•*>■■ n v-';v rf ' <• ^ SURGEON GENERAL'S OFFICE LIBRARY Section___ Form 113c iVo. W.D..S.G.O. ,.1US£S \ ERNJfENT PRINTING OFFICE ^ ^ V^w >^^C^^sC,lK>Ptare>;* r>; < "-'J THE STUDENT'S MANUAL AND HAND-BOOK FOR THE DENTAL LABORATORY. SECOND EDITION. BY L. P. HASKELL, PROFESSOR OF PROSTHETIC DENTISTRY, DENTAL DEPARTMENT OF THE NORTH- WESTERN UNIVERSITY, CHICAGO. To which is appended Dr. E. H. Angle's System of Appliances for Correcting Irregularities. PHILADELPHIA 189c. Copyright 1890, by The Wilmington Dental Mfg Co, Philadelphia. CJLaa^vn_-C_JL wu H343s 1830 PREFACE TO FIRST EDITION. AT the urgent advice of members of the profession, I have prepared this work, for which there seems to be a place in the laboratory of the young dentist, to say nothing of the older members of the profession, who, in these days of rubber plates, have had little experience in metal work. The text-books are too diffusive, embodying too many methods for the same object, confusing to the student, and inconvenient as hand-books. This book will embody the result of forty years' expe- rience in the dental laboratory and exclusive attention to prosthetic dentistry, furnishing methods which have been thoroughly demonstrated as simple and effective, producing satisfactory results. It is not intended to take the place of the text-book in the dental college, though the student will find it there a valuable aid in the prosecution of his preparatory work. PREFACE TO SECOND EDITION. FOR the flattering reception the first edition of this work received at the hands of the Dental Journals, and the profession at large, I desire to return my thanks. Suggestions from several sources as to additional illus- trations have been heeded. My reason for including in this work Dr. E. H. Angle's system of appliances for correcting irregularities is, that it is the most simple, and at the same time effectual, of any thing that has been devised, avoiding plates and ligatures, occupy- ing but little room in the mouth, unintermittent in its operation, and requiring no additional appliances for retain- ing purposes. Dr. Angle has re-written and largely illus- trated his work. The suggestion has been made that I embody a chapter on crown and bridge-work. This covers so broad a field, with such an infinite variety of methods, and constantly increasing, that a work devoted to this subject is necessary, and such a one has already been prepared by Dr. George Evans. CONTENTS. General Principles................................................ 5 The Laboratory.................................................... 6 Tools and Appliances............................................ 8 Blow-pipe, etc.................................................... 9 Impressions...................................................... VI Plaster Casts............................................... .... 14 Dies............................................................. 17 Swaging Plates.................................................. 20 Fitting Plates.................................................... 23 Clasps............................................................ 24 Investing, Backing, Soldering........................................ 26 Preparation of Metals and Making Solders........................... 29 Attachment of Teeth to Plates.................................... 31 Relative Value of the various Materials for Plates ................. 32 Combination Work.............................................. 33 Continuous-Gum.................................................. 35 Cast Metal Plates............................................... 43 Vulcanized Rubber................................................ 45 Celluloid......................................................... 4S Repairing...................................................... 49 Selection and Arrangement of Teeth............................... 51 Temperaments................................................... 54 Temporary Work................................................ 64 Adjustment in the Mouth ........................................ 65 The Angle System of Regulation and Retention of Teeth............... 67 Fractures of Maxillary Bones ...................................... 90 CHAPTER I. (JEXERAL PRINCIPLES. IN examining the mouth for the insertion of an artificial denture, there should be taken into account all its condi- tions, viz.: the shape of the jaws, long or short, deep or shallow, hard and unyielding, soft and yielding; a solid, alveolar ridge, or one from which the bone has been absorbed, leaving a flexible condition; the relative position of the jaws, whether the lower is receding or protruding; and then the remaining teeth, if there are any ; for often a few teeth are left, sometimes useful; but often not only useless, but interfering with the comfort and usefulness of the artificial denture. If the patient is better off without them, advise their extraction. The first object to be attained is comfort and usefulness; next, artistic appearance, or resemblance to nature, not only in the size, shape, color, and arrangement of the teeth, but in forming the artificial gum, be it rubber or porcelain, so as to restore the contour of the lips. The selection of material for plates the patient should leave to the dentist, presuming he has been properly educated as to the relative value of each. Whatever materials and methods will secure the best results should be adopted. The remark is often made, " I do not have any demand for metal plates." That is true, in consequence of the uni- versal use of rubber; consequently you must create the demand by showing your patients the superiority of the metal, and the disadvantages of the rubber. 5 CHAPTER II. THE LABORATORY. IT should not be a machine shop, but adapted to, and arranged for, the object intended. It sho.uld be large enough for all the purposes of a dental laboratory, well lighted, and easy of access from the opera- ting-room. The work-bench should be in front of the window, as it is difficult to work advantageously by a side light. The bench should be of hard wood, about 18 inches wide, 1J inches thick, and of a proper height to sit down and work at easily. The gold drawer should be 2 feet long, 18 inches wide, 6 inches deep, with the front cut out in a half circle, so as not to be in the way in filing. In it should be a " gold- pan," 14x10, and 1£ inches deep, with a top depressed in the centre, and perforated with small holes for the filings to pass through. There should be a hard-wood knob in the bench over the draAver to file on. If there is plenty of room, a second drawer Avith knob, for rubber-Avork, is desirable; also a drawer for refuse AA^ax, and OA-er Avhich to "wax-up." The plaster-bench should be constructed Avith a hole in the centre, for refuse plaster to drop through into a box or barrel; shelf for flasks, and a tin can for plaster. The molding-box may be 18 inches square and 4 inches deep, placed as a permanent fixture, Avith shelves for flasks, dies, etc. The lathe should be a permanent fixture on a bench, Avith good light, and sufficiently high to stand at. A ma- chinist's lathe is not adapted for dental purposes, AA'hile we have dental lathes admirable in all their appointments. Have a rack for the appliances. 6 AND HAND-JBOOK. / Fig. 1. The tools should be arranged at the back of the bench, within easy reach, and never in a draAver. Have in the rack only such as are needed for dental purposes, laying duplicates aside. A movable swaging-block (Fig. 1), to be kept under the bench, by the side of the gold-drawer, is made as folloAATs: 8 inches Avide at the top, and 11 inches at the bottom, just high enough to pass under the bench. Make it of pine, Avith a plank bottom, to Avhich attach heavy castors, a handle on one side, and a pocket for the ham- mer. Have an iron six inch cube cast, and nearly filling the box full of saAv- dust, place the cube in it so it Avill extend 2 inches aboAre the box. If you intend to make Continuous- gum Avork, provision should be made for a furnace. MOVABLE SWAGING BLOCK. CHAPTER III. TOOLS AND APPLIANCES. D ENTAL depots are filled Avith appliances, many useless, others sometimes useful, but not necessary. The fol- lowing are indispensable: FOR METAL WORK. Straight Shears, with openings for the Plate Nippers. fingers. Plate punch. Hammer, for swaging. Horn or wood mallet. Files, round and half round. Small vise and anvil. Slate, for borax. Sheet-iron soldering pan. Articulators. Lathe appliances. Felts and brushes for polishing. Acid dish, lead. Sieve. Molding flask, 5 in. diameter, 3 in. deep, of iron. Plate Benders (lower.) Gas-pipe, so arranged as to be used for soldering, "waxing up," vulcanizing and melting metals. FOR RUBBER WORK. Pliers, cutting. Pliers, round-nosed. Pliers, flat-nosed. Hammer, riveting. Plate burnisher, flat. Tweezers, for solder, etc. Reamer, for countersink. Blow-pipe, mouth. Carbon or asbestos soldering-block. Lathe, cone-bearing. Circular saw, large and small burs, and drills Two ladles. Stick for packing. Two lizes of rings for counter dies. Vulcanizer. Wrenches. Scraper, round shape. Chisel, with thin edge, for trimming around necks of teeth. Small pointed instruments for finish- ing between the teeth. Saw-frame and saws. An instrument for waxing up, straight and pointed at one end, and slightly curved at the other (Fig. 12). Bowls, medium size. Shellac bottle (wide mouth). Flasks. Press. Calipers. Files, two grades. Plaster-knife. Heavy tea or dessert spoons for mix- ing and handling plaster. Oil bottle. AND HAND-BOOK. 9 FOR CELLULOID. All tools used for rubber except vulcanizing flasks and press, substituting celluloid flasks and press. FOR CONTINUOUS GUM. Furnace. Muffles, slides, tongs, and poker. Porcelain Boxes, for mixing material. Camel hair pencils. Instrument for applying material. Stiif Brush. TO THE ABOVE CAN BE ADDED : — Automatic blow-pipe. Rolling Mill. Furnace, or melting apparatus. Tongs for crucible. Ingot Mold. Plate gauge. BLOAV-PIPE, ETC. Every student should learn to use the mouth bloAv-pipe. The first thing to be done is to secure a proper bloAv- . pipe. Those usually sold at the depots are made for jewelers, who solder small objects Avith a Ioav grade of solder, and not invested as teeth are. The Wilmington Dental Manufactur- ing Company have bloAv-pipes made at my suggestion. The mouth aperture is f, and the small one 1-16 inch. The end should not be taken between the lips, as it tires the muscles too much, but pressed against them. There must be a supply of air in the lungs constantly, so do not alloAv a complete collapse of the diaphragm, at the same time pressing the tongue against the palate to prevent the lips collapsing Avhile drawing in a fresh supply through the nose. A little practice, observing these rules, Avill soon enable one to use it successfully. The automatic blow-pipe, operated by foot belloAArs, is useful in the laboratory. The are tAvo very desirable ones, one of AAThich is Dr. L. M. MattheAv's -'Little Giant," manu- factured by TheWilmington Dental Manufacturing Company. CFig. 2). The other is manufactured by The Buffalo Dental Manufacturing Company, knoAvn as Xo. 6F. 10 STUDENT'S MANUAL Fig. 2. DR. L. M. MATTHEW'S " LITTLE GIANT BLOW-PIPE." The proper gas-jet for soldering is a wire bulb, made by leaving the end of the gas-pipe with no burner and winding over it fine binding-wire, till a bulb about one inch in diam- eter is secured; the same results may be obtained by making a bulb of several thicknesses of fine wire-gauze over the end of the pipe, and bound tightly to it. The Mcintosh Battery Company, Chicago, have recently, at my suggestion, made a wire gauze burner that can be screAved to the gas-pipe. The object is to break the force of the gas, and add more oxygen to it; in this way, a flame like an alcohol lamp is secured, which can be easily controlled by the Woav- AND HAND-BOOK. 11 pipe, and in heating up, the Avhole flame can be taken within its scope. The gas fixture should be horizontal, Avith two lengtlis, so as to place in the most coiwenient position Avhile using. Fig. 3. USING BLOW-PIPE, AND SHOWING BURNER AND SOLDEI CHAPTER IV. IMPRESSIONS. THE success of the artificial denture depends on a correct impression as the foundation for the work, therefore care should be taken to insure success. As to materials, I differ Avith many instructors. In some cases, good impres- sions can be taken in Avax, more in the modeling compound, but plaster is a material always to be relied on. It may be accepted as an axiom that the more difficult the case to obtain an impression of, the greater need of plaster. For a Full Upper, spread a large napkin over the dress; select a cup as near the size of the ja-Av as possible; as it is necessary to obtain a high impression over the cuspids, place a little wax OA>er the outside of the cup at those points, also over the posterior corners, if the tuberosity is deep, and raise the palatal surface at the rear a little if the arch is deep. Mix the plaster to the consistency of thick cream, and add a pinch of salt, at the last moment, after the plaster is ready, as you do not want to hasten the setting till after placing in the mouth ; stand at the right side, and with the left hand distending the lips, press the rear of the cup into place, and so, forcing any excess forward, press the cup into place, at the same time telling the patient to " keep the tongue quiet, and not to be concerned about what runs over at the rear," then pressing the lip so as to force the plaster well up under it. If there is nausea, tell the patient to resist the tendency, as it will be over in a few moments. As soon as the plaster has set, Avhich can be ascertained by breaking off a piece of the surplus in front, remove by raising the lip high, and working the impression so as to let in the air. For a Fall Lower, proceed as above, only standing in front of the patient, and as the cup is passed into place, press 12 AND HAND-BOOK. 13 the cheeks aAvay from the cup, so there shall not be a fold ol membrane underneath. For a Partial Lower, Avith the anterior teeth remaining, select a cup Avith an opening for the teeth, and through AA'hich they will pass easily. Wet a piece of paper and lay over the opening, and, holding the cup in the palm of the hand, put in the plaster, and place in the mouth, ahvays pressing away the plaster from the front before inserting, so as to have as little outside of the teeth as possible, as it will facilitate its remoAral. If there are molars remaining, so that the sides of the cup will not go deep enough, place wax on the outer edges. Sometimes the teeth stand in such a position that the plaster must, of necessity, break ; this is of little import- ance, as the pieces Avill readily go together again. For a Partial Upper, proceed as with a full upper, only, before inserting, press aAvay the plaster from the sides of the cup Avhere there are teeth, as there Avill be enough to go out- side. Do not let the plaster set as hard as in full cases, or the cup will leaA-e the impression, and the plaster have to be broken away in pieces. This can ahvays be avoided, and should be, as it is very unpleasant for the patient. Never take an impression in wax, and then plaster in it; for while the plaster Avill break just the same, it Avill often be difficult to replace, or even save the pieces, Avhen the}' are thin; there is nothing to be gained by it. Be sure your impression is good before dismissing the patient. It is a simple process, only avoid using an excess of plaster, and too large a cup. CHAPTER V. PLASTER CASTS. HILE there are various methods of preparing the impression, I much prefer shellacing, ahvays using it thin, so it Avill strike in, and not make a skin on the surface. By shellacing it is easy to tell Avhat is cast and AAThat is impression, Avhen separating. Next, oil lightly, and turn the impression face down Avhile mixing the plaster. Mix the plaster the same as for the impression, about the consistency of thick cream; place but little in the impression at first, and jar thoroughly so as to drive out all air. When hard, remove the cup, and Avith a sharp knife pare the impression to near the teeth, if there are any, or to the cast. With a blunt-pointed knife, proceed to break it aAA7ay, beginning at the heel and pressing with the thumb to guard against the knife going into the cast. For a full upper, make the folloAving changes in the cast. In most cases, the palate is hard in the centre, and as the rest of the surface will yield invariably to pressure, the plate Avill bear hard and irritate, and rock. Therefore relief should be provided by raising the plate Avhere the palatal bone is hard. If it is to be a rubber plate, scrape a portion from the plate Avhen finishing. For a metal plate, it is better to raise Avith a thin film of Avax along the entire hard palate, about 3^ inch in depth, graduating to the edges so as to shoAV no line. The amount of surface thus covered will vary in different mouths; some quite Avide, others narroAv. At each side of the hard palate, at the posterior edge of the plate, scrape the east slightly, so the plate will hug snugly there 14 w AND HAND-BOOK. 15 (Fig. 4). If there is a flexible ridge in front, its normal condition is where the plate Avhich has been worn has pressed it, and Fig. 4. there it should remain, for no change of posi- tion Avill im- prove it; it AA-ould be better if the patient would submit to its removal. No air cham- bers are needed in full plates. If the plate comes in close contact with the membrane, there will be all the adhesion necessary to sustain the heaviest Avork. Mix plaster, spread on a smooth surface, and set the cast into it, so as to make the Avhole about If inches high ; if the cast is slightly under-cut, raise the front a little, and then form the plaster around the sides so as to have them flaring. The object is to facilitate the removal of the cast from the mold, as it Avill deliver itself better than if rented Avith the fingers. Fig. o. If the case is badly undercut, either in front or at the posterior corners, make a "core" (Fig. 5) as folloAvs: Set the B 16 STUDENT'S MANUAL cast, after it is ready for molding, on a smooth surface ; oil the surface, where undercut; mix plaster and asbestos, equal parts, and lay on the surface J inch wide at the base, up to the top of the cast; when hard, remove, trim, and dry perfectly for molding. For full lower, prepare for molding as above, having, pre- viously to filling the impression, removed a little from the sur- face of it, in the extreme depression, or what represents the summit of the jaw, so the plate will set more easily. If the lower case, either full or partial, is badly under- cut, make a " core," in two sections, one transversely across the heel to past the cuspid, and the other to lap on to this one (Fig. 6). In this way a perfect die may be obtained. Fig. 6. If it be a partial lower, leave the anterior teeth on the cast, building up with plaster against the front to have the cast flare, cutting off all other teeth from the cast. Yov partial uppers cut off all teeth. If for suction, relieve the hard center, as in full sets ; or if deemed best, put in an " air-chamber." Some patients will wear a plate without, others will think they cannot. CHAPTER VI. DIES. THE qualities requisite for a dental die are these: non- shrinking ; hard, so as not to batter in swaging ; cohe- sive, so as not to break ; furnishing a smooth surface ; fusing at a low temperature. Babbitt metal is the only alloy that furnishes all of these qualities. My use of it for thirty-five years has fully demon- strated its complete adaptability to this use. But as there are many formulas, it is important to have one suited to this purpose. This is: copper, one part; antimony, tAA*o parts ; tin, eight parts. These should be melted in the order named, as tin would oxidize badly before the first Avas melted if all Avere placed in the crucible together. As a strong heat is required, it is Avell to use a furnace, or a blacksmith's forge. Melt and turn off into ingots, and re-melt. Babbitt, made from this formula, can be had of the leading dental supply manufacturers. If it should not be found to run freely from the ladle, Avhen making a die, add some tin. For Counter Dies. As lead fuses at a higher temper- ature than Babbitt, and AA^ould adhere to it Avhen poured on it, reduce the melting temperature by the addition of tin,— five parts lead, one part tin ; this also hardens it, Avhich is an advantage, as lead is too soft for the counter die. The use of oiled, sand is of great advantage, because it can be used many times Avithout re-oiling, when properly prepared, avoids bubbling and other delays incidental to AAretting sand, and can be packed harder. Use sAAreet oil, making the sand of the same consistency as when Avet. If too much is in, add more sand. AAroid the use of sand which is very fine. The molding-box, ring, and flasks have been described in a previous chapter (II). It is necessary to sift the sand 17 18 STUDENT'S MANUAL only after u?ing several times, and then only on the surface of the model. Pack hard at first around the sides, so the sand will not drop out of the ring, and then gradually add- ing and packing till full. In most cases, the model will drop when lifting the mold. If it does not, jar the edge of the ring on the edge of the molding-box. A potato-masher is well adapted for packing the sand, using the small end for the sides, and large end for the top. It is a good plan to rub pulverized soap-stone on the model before molding, especially when the sand is first used. Melt the Babbitt, and do not pour Avhen very hot, but stir till it has cooled a little, so it wilL not burn the sand much. Be careful not to injure the metal by over-heating it. Do not cool the die suddenly in water, as it tends to make it brittle. After it is cool, coat with whiting, wetting and rubbing it on with the finger. Set it into the sand half its depth ; place a small ring or flask around it (Fig. 7); melt the lead Fig. 7. DIE READY FOR CASTING THE COUNTER. and turn, but do not fill the ring full, leaving space to grasp it Avith pliers, and plunge into AATater. It is never necessary to swage in the ring. AND HAND-BOOK. 19 In molding an under-cut case, put the " core'"' carefully in place, and mold as before ; the AAThole Avill drop out; replace carefully the core, and pour the metal. When cores are needed at the posterior corners, or in loAver cases, before making the counter die pack a little sand into the undercut, so the die and counter will separate; then, after the plate has been swaged as far as the counter will permit, bring the plate into place in the under-cut Avith the flat burnisher, or, if necessary, Avith a round faced hammer. It is sometimes necessar}7 to make a second die, but not generally Avhere Babbitt is used. If the case has a deep arch, make a half counter, just filling the arch, and not extending on the ridge ; by so doing there is less danger of tearing the plate in the arch, Avhen sAvaging. The use of Babbitt metal for dies very greatly simplifies the making of metal plates. CHAPTER VII. SWAGING PLATES. CUT a pattern for the desired plate; for this there is nothing so good as Japan tea-chest lead; it is thicker and stronger than the Chinese. The grain of the plate should ahvays be crosswise of the die, as in the SAvaging there is far less danger of its tearing, and, of course, is stronger in wear. Oil the dies to prevent, as far as may be, base metal from adhering to the plate ; if metal adheres, Avipe it off, as it will eat into the plate when heating. Anneal by heating to redness; as the surface oxidizes, clean by dropping while hot into equal parts sulphuric acid and Avater. For an acid dish there is nothing so good as lead; it is easily made by forming it of thick sheet lead, over anything of proper size, about 4 inches diameter, 1 inch deep, Avith a handle cut in the same piece. Sulphuric acid can be boiled in these, and they Avill last for years. If the case is a full upper, use the mallet in the arch, and if deep, sAvage Avith the half counter; the bending pliers (loAver ahvays) will be found of value in shaping the ridge; to save time, and against Avhich there is no possible objection, cut the edge of the plate in front, lap, and, after fully SAvaging,solder. If the plate is soft,like 20 karat,or pla- tina, tAvice annealing is sufficient, ordinarily ; always cleanse in the acid after annealing. There is danger of over-swaging. If the case is under-cut, after full SAvaging place on the plaster cast, and burnish into the depression more fully. With the Babbitt metal die it will be seen that the plate fits the plaster cast snugly, so much so that sometimes it Avill not come full up to the cast in the centre; it will, however, come to its bearings at that point in the mouth. 20 AND HAND-BOOK. 21 To aid in restoring the contour of the lip, trim ahvays so as to have the highest points over the cuspids, but drop suddenly back of those points so as to give free play to the muscles. (Fig. 8.) The plate can seldom be Avorn as high Fig. S. as the impression indicates back of these points, but leave the plate high enough, so that on trying in, it can be trimmed as desired. Be sure there is room for the frsenum by cutting or filing an opening for it. Ahvays extend the plate over the maxillary tuberosities, hoAA^ever large, as it aids in keep- ing the plate in place, preventing its slipping forward. The edge of a plate should never be SAvaged to form a " rim," because the edge should be left for trimming by the mouth. If a rim or binding is needed, solder one on; it is easily done, and looks better. It is best not to solder a Avire or rim to a loAA^er plate, either full or partial, because it is often necessary to alter the margins. If it is a gold plate, it should be a rubber attachment, and this makes a good finish to the margins. If continuous gum, double the edge all around | inch wide. Then, if alterations are needed, the appearance of the work is not marred. In SAvaging a lower plate, use the bending pliers first. If the gum is flat, double the plate about 1 inch in the center. 22 student's manual In trimming a lower plate, it should be remembered that much trouble arises from its being made too deep, so as to infringe on the muscles and loose integuments. The plate is thus lifted by them, and they in return are irritated by the plate. In swaging a partial lower, the plate should be SAvaged in two pieces, as it facilitates the process, and doubles it where needed. Cut each pattern so as to extend from the posterior to \ inch beyond the cuspid, or bicuspid, if any remain. Always carry the plate above the necks of the teeth, about half way, as often the attachment of the muscles is so high it necessitates making the plate very narroAV, unless it is carried higher, and it will set firmer for so doing. Swage each piece separate, and then SAvage together; putting borax betAveen, clamp Avith small wire clamps (hair- pins make good ones); one of the pieces will usually overlap the other, or if it does not, both may need trimming; trim one, leaving the overlap on the other till after soldering, so as to lay the solder on the OA^erlap, draAving through till it can be seen on the other edge. In swaging a partial upper, use the mallet first, and the bending pliers if needed. If it is to be a clasp-plate, extend the plate \ inch beyond the tooth to be clasped, as the plate Avill set steadier. Double around Aveak points, either each tooth separately, or in one piece \ inch wide around the Avhole plate, laying the solder on the overlapping points, and draAving through; if laid on the inner edge, there is danger of flowing it on the plate. It is neATer Avell to double the whole width of plate. CHAPTER VIII. FITTING PLATES. IN the full upper [date, see that it sets steady. If the ridge is flexible, it must inevitably yield to pressure. The point of great importance in securing suction is at the posterior margin, in the centre. See that it sets close enough to exclude the air. This can be done by wetting it before placing in the mouth, and then by a pumping process, watch- ing for the escape of air-bubbles; if any appear, place on the model and burnish closer. It is equally necessary to see that it does not press so hard at that point as to irritate and then loosen ; this is often the case. After trimming the outer margin, turn with the pliers, the extreme edge about one thirty-second of an inch, to guard against irritation. Plates can be worn higher than many dentists imagine, judging by the Avay they are usually trimmed. They should be worn as high as possible, especially over the cuspids. In fitting a partial upper plate, see that it does not in- fringe on the necks of the teeth, wearing, making them sore, and displacing them, and preventing the plate coming to its place on the membrane. In fitting a full lower plate, see that it sets steady; have the patient raise the tongue to the palate, and see if it lifts the plate; then lift the lip in front and at the sides, and, if there is interference, trim accordingly. In fitting a partial lower, see that it does not press against the teeth, and obseiwe the rules as in the full loAver. Ahvays be satisned that your plates fit before taking further steps. 23 CHAPTER IX. CLASPS. THE use of the clasp is not objectionable if properly adapted, and kept clean. Often, Avhen bridge work is used, a nicely adjusted narrow plate, properly clasped, would be less objectionable than unremovable fixtures,- saving, instead of destroying, the teeth attached to. Clasps should not be so Avide as to cover a large portion of the tooth, being cumbersome, and looking badly. Neither should they be very narroAv, as is the custom with English dentists, as they Avear into the enamel. Asa rule, about one-eighth to three-sixteenths of an inch Avide is sufficient. The material should be eighteen karat alloyed with platina, so as to be springy; in thickness about twenty-four gauge. In selecting teeth for clasping, the second bicuspids are preferable, if the way is clear for using them, because of their straight sides, and being in a position to sustain the plate in balance. The second bicuspids are preferable; if none, then the first, especially if there is to be a small plate of few teeth. The first molar next, especially if it is a large plate. It is not advisable, except in rare instances, to wedge or file teeth for the purpose of using clasp3. If those to be clasped to are the only teeth left of the upper set, the clanger that eventually they may be lost would indicate the advisability of making a suction plate, so that the plate would still be useful; but while they remain, use clasps to steady the plate in mastication. Fit the clasps to the plaster teeth as accurately as pos- sible ; then fit them to the natural teeth ; if the clasp is on a bicuspid, do not let it pass in the front if it can pass around 24 AND HAND-BOOK. 25 the back; in other words, avoid its showing, if possible. If it is on a molar, and can pass all around, let the ends meet at the labial surface. After fitting, spring open slightly, so as to remove easily ; with Avax firmly attach it to the plate, uniting the tAvo, and placing in the mouth, press both into place, and carefully remove. Invest the clasp and a small portion of the plate in plaster and pumice; Avarm and re- move the wax; fasten the plate and investment together with a Avire clamp, so that they may not become separated Avhile heating ; if there is a space betAveen the clasp and plate, as it is sometimes not advisable to put the clasp high up on the tooth, put a piece of gold betAveen when solder- ing the clasp to the plate. Never unite them for a space of more than three-sixteenths of an inch, thus leaving full play for the elasticity of the clasp. To prevent the solder flowing beyond this point, put plaster into the joint. Adjust but one clasp at a time, and round and thin the ends in finishing. CHAPTER X. INVESTING, BACKING, SOLDERING. IT is well to have several sizes of sheet-iron rings, one inch deep, to invest in. Select one a little larger than the case, then there will not be superfluous plaster to heat up and keep hot; and the case is secure from accident in handling. Mix equal parts of plaster and sand (some use asbestos, but it is more expenshre, and is not so solid to back-up in). Be sure it comes in contact with the plate, for if there is a space underneath, there Avill be danger of melting a hole in it. When hard, Avarm and remove the Avax, then, setting it in the sink, dash hot Avater on it. I prefer backing-up in the investment, as it avoids the necessity of investing separately and heating up and solder- ing twice, and it can be done as Avell as by the other method. For backing, the gold should be thicker than the plate. I use clasp material. Cut off a strip the Avidth of the teeth ; shape the end to the plate; put coloring, ink, or other material, on the head of the pin, and press the gold on it, and punch ; enlarge the surface of the opening with a small " countersink;" if it is a back tooth, cut off" the gold even with the croAvn ; if a front tooth, it looks better a little shorter, Avith the ends rounded and chamfered. If they are gum teeth, shape to the shoulder on the gum, and let them meet only at that point. If plain teeth, do not let them meet at all. After it is shaped, bend slightly so it will fit snugly, and AATith a sharp, chisel-shaped instrument split the head of the pin; it is better neArer to rivet, as, if only split, the solder will Aoav around the pin in the hole, and fasten more securely than riveting, as the solder Avould hold only 26 AND HAND-BOOK. 27 on top of the pin. It is Avell to cut off the head of the pin, if too long, before putting on the backing. If there are spaces under the teeth, fill Avith foil. These should be avoided, as far as possible, by close grinding. See that the surface of the plate is clean; mix pul- verized borax on a slate or glass, having it sufficiently wet to spread easily. Cut the solder small and lay it where you wish it to floAV. Place it to heat over the gas, and let it heat sloAvly for fifteen minutes, then turn on the full heat, and Avhen as hot as that will make it, place in a small soldering pan (Fig. 9), and throAv a full blast on the outside Fig. 9. SOLDERING PAN. first, then upon the plate, heating equally plate and backing, till the solder flows. If the solder is Avhat it should be, it Avill sweat down Avhere it lays and blend in with the plate. To insure this, the solder should be of the same karat as the pla^e, eighteen to twenty. The nearer the melting point of the plate, the better the results, and the less labor in finishing. The entire surface of the plate should be exposed. If it is a loAver partial, cut out the plaster in the centre entirely, so there will be an opening to prevent the flame rebounding. As soon as cool, place in Avater to soften, remove the investment, and place in the acid to boil; this cleans the 28 student's manual plate and remoATes the borax. To remove the acid from under the teeth, put the case into a solution of soda. With the file remove all sharp corners and edges; Avith fine, small corundum smooth the surface OATer the pins and wherever the solder has not flowed properly. Drive a pine stick into the chuck hole of the lathe, and with a sharp pocket-knife turn it to a point and finish the entire surface with pumice, following with small-sized, soft brush-wheels, and finally with Avhiting or rouge. CHAPTER XL PREPARATION OF METALS AND MAKING SOLDERS. IF a dental depot is easy of access, better buy than prepare plate and solder; jewelers are not usually expert in preparing them. Gold plates of a loAver karat than eighteen should never be used; I prefer twenty. It should be made with pure gold alloyed with pure copper and silver, one part of the former to tAvo of the latter. For tAventy karat, one ounce of gold and four pennyweight of the alloy; for eighteen karat, one ounce of gold and six pennyweight of the alloy. Place in a crucible with plenty of borax, and melt, and turn into the ingot mold. Roll lengthwise to the necessary width of plate; then anneal, and roll to guage twenty-eight, which is a suitable thickness for all plates, except lower, which should be thicker; additional strength in special cases being obtained by doubling. To Dispose of Scraps, Filings, and Old Plates.— Save all clean scraps and portions of old plates that are free from backings, clasps, and solder, and melt. All else, in- cluding filings, through which a small horseshoe magnet has been passed to remove steel particles, should be subjected to a strong heat with saltpetre. If it does not come out touo-h, subject it to corrosive sublimate. If this does not do, send to an expert. This product usually has enough platina in it for clasp material, and can also be used for backings. To -make clasp gold, take tAventy karat plate and add two penny Aveights platina. Melt the gold, and rolling the platina as thin as possible, drop into the gold when melted. The gold acts as a flux, and the platina is melted. Gold Solder.—The leading dental depots provide now an admirable quality of solder. But if you wish to make it, 29 30 STUDENTS manual the following recipe, by an old expert, Dr. D. H. Goodno, makes a solder that has all the qualities desired, being remark- ably tough, floAvs readily, and does not discolor in the mouth. He says he has rolled it as thin as a ribbon of pure gold: Forty grains pure gold, tAvo-and-one-half grains pure silver, tAvo-and-one-half grains pure copper, three grains pure zinc ; place the zinc in gold foil and place at the bottom of the cru- cible ; cover with borax; cut the other material fine and place in the crucible, and cover Avith borax ; melt and roll. Another recipe is made as folloAvs, by first making an alloy : three pennyAveights pure silver, three pennyAveights- pure copper, one-and-a-half penny Aveights pure zinc. Roll the zinc in gold foil and place in the crucible, and cover Avith borax ; place the copper and silver on it and cover Avith borax, and melt; roll thin, and use according to the karat you Avish; for tAventy karat, five pennyweights pure gold, one pennyAveight alloy ; for eighteen karat (and there is no- necessity for using a loAver karat in the mouth), five penny- Aveights gold, one-and-a-half pennyweights alloy. Ahvays test your solder by floAving on silver plate. • Silver.—For partial sets, when the patient cannot afford gold, silver makes a good substitute. But coin silver should never be used, as it oxidizes badly in the mouth. Pure silver, alloyed Avith platina, makes a good plate, Avhich, of course, discolors from the presence of sulphuretted hydrogen . in the mouth, but is easily cleaned ; tAvo penny Aveights of platina to the ounce of silver is sufficient. For clasps for silver plate use gold ; and I prefer to solder Avith gold, using eighteen karat. Silver solder is made as folloAvs: Silver, six parts; copper, three parts; zinc, tAvo parts; melting the copper and silver, and then adding the zinc. • CHAPTER XII. ATTACHMENT OF TEETH TO PLATES. AS a rule, in partial sets, the teeth should be backed and . soldered. In full upper sets, it is no longer necessary to use the single gum teeth, and it is not advisable, for it is impos- sible, with them, to secure proper arrangement, articulation, and restoration of contour; besides, the work is not cleanly, on account of secretions getting between the teeth and plate. By using single plain teeth, and pink rubber attachments, the best results can be attained, next to continuous-gum. For partial lower on gold, this method is the best, for the reasons mentioned, and also because there is such a ten- dency of the process to give Avay, in these cases, that it is necessary, from time to time, to remove the teeth and set them higher, and this, of course, is easily done, if the rubber attachment is used. Sometimes partial uppers may be constructed in the same manner, especially when all the back teeth are replaced. The method of attaching is to invest the case, as if it were to be a rubber plate ; then solder platina loops at inter- vals on the plate ; the loops may be T*ff inch wide, one-quarter inch long, .soldering the ends, or soldering the middle with the ends turned up. In an upper case put four such near the upper edge and four on the ridge. After soldering on the loops, place the flasks together, and see that none of the teeth come in contact with the loops so as to prevent closure of flask. Another method is to spur the surface Avith a sharp in- strument; this, hoAArever, cannot ahArays be relied on, but deep spurs in the cast metal plate are sufficient. c 31 CHAPTER XIII. RELATTVE VALUE OF THE VARIOUS MATERIALS FOR PLATES. FOR full upper sets, continuous-gum stands pre-eminently the most perfect, in all respects, of anything ever devised, provided it is made as it ought to be, and full advantage taken of its capabilities. It most nearly resembles nature, not only in the arrangement of the teeth, but in the disposal of the gum and imitation of the palate; it is the most cleanly, and the materials are in no Avay objectionable in the mouth; I have found it the strongest work. More than thirty years' use has demonstrated the truth of these statements. Next in value for full upper and in nearly all partial cases is gold. This has been used from the earliest history of artificial dentures, and has been fully tested. Next in order for full uppers may be mentioned platina, with rubber attachments. For partial uppers, some use platina ; but if it is pure it is too soft for the purpose; it may, however, be alloyed with iridium. For partial lower, gold is the best, Avith exceptional cases, AAThen rubber (the black or the maroon) is perhaps better. For full lower sets, where the gums show, which is rare, continuous-gum, should be used. Cast metal plates, with rubber attachments, using Watts', Weston's, or Reese's metal, make a good lower denture. Aluminum is used to some extent, but is objectionable for several reasons. If the plate should crack from any cause, there is no solder suitable for the mouth, Avith which to re- pair ; often there are iron spots in it, which rust through, 32 AND HAND-BOOK. 33 making holes. Recently, however, a method of casting these plates has been devised, Avhich seems to produce excellent results, and is the method Avhere pure aluminum is used. Next in order is rubber, used the world over more than any other material. But, while thus used, it is open to serious objections, doing in many cases much harm to the mouth; a subject it is not necessary to discuss here. It is not, however, an unmixed evil; it enables many people to wear artificial teeth Avho would otherwise be unable to afford them; then for temporary Avork it answers every purpose; in some cases for partial loAver it is Avell to use it. The last on the list, celluloid, is the least in ATalue; hav- ing given it a thorough trial, for six years, I AAras compelled to abandon it. I could not recommend it to my patients longer. The objections to it are those pertaining to rubber, besides being more uncleanly, absorbing the secretions. It is difficult to repair, and is injured in appearance by the process. There is still another material, the porcelain plate. But to make this requires long practice, and eA^en then it is im- possible to secure all the results necessary for a perfectly artistic denture. When done it is ahvays difficult to repair.^ and sometimes impossible. COMBINATION AVORK. There is but one kind of " combination work " that is advisable, and that is metal plates and rubber attachments. The combination of continuous-gum on a rubber base Avas made quite extensively twenty-five years ago, and, as might have been expected, Avas abandoned. It, however, came to light again, across the Atlantic, a feAV years since. The objection to it is the difficulty of repair. If a tooth is broken, the continuous gum-portion must be removed and repaired, and a neAV rubber plate made, involving too much expense for the replacement of a tooth. The same objection holds good in continuous-gum and cast metal plates. 34 STUDENT'S MANUAL The combination of rubber and celluloid is a difficult kind of work to make, for which a good price should be charged, and then the price charged would have paid for a metal plate, Avhich would have been far preferable. The combination of celluloid and gold is objectionable, for the reasons that apply to the celluloid alone, and also that the celluloid does not adhere to the plate, and jn case of repair is just about ruined. I CHAPTER XIV. CONTINUOUS-GUM. THIS is the most difficult to make, and yet the most per- fect when completed. It has stood the test of time, and remains to-day unparalleled as an artificial denture. I do not see hoAv there can be anything superior to it, at least in its adaptation where a porcelain gum is an absolute necessity, and must be very high and very thin, Avith no seams. There cannot be too much care bestowed on its construc- tion, and it amply repays the careful operator who avails himself of all its possibilities; Avith this work the shape of the teeth can be modified by grinding, or building on to, and Avhen it is finished, the enamel, where ground, has again fused. The plate should be swaged the same as for gold, using the best French plate, gauge twenty-eight. After fitting, and articulating bite secured, place in the articulator and remove the wax. With lead make a pattern about I inch Avide, covering the entire posterior of the plate, and around the corners. This is for a "doubler," (Fig. 10,) and should be gauge thirty. Fig. 10. First swaging doubler. slightly to the top of the tuberosity; clamp with tAvo clamps across the center, after putting in a little borax; solder (always using 35 36 student's manual pure gold, as alloyed gold would discolor the gum in bak- ing) for about J inch; removing the clamps, replace on the model, and burnish again closely, and clamping, solder still farther, and so continue, by degrees, until finished. Take round wire, gauge eighteen and roll to gauge twenty- one. File one edge flat, and beginning where the inner edge of the " doubler" is turned up, at top of tuberosity, fit the wire with pliers for the distance of If inches, clamp and solder only I inch; then place on the model, and fit closely, a short distance each way, and solder again, always clamping tight, and so on till it is all attached. The teeth being arranged, insert, in equal parts, plaster and asbestos, leaving it about J inch thick underneath and all around. When hard, warm slightly and remove the wax, finally dashing boiling water into it, so as to thoroughly cleanse of wax. Turning up the pins, make three patterns, one each covering the molars, bicuspids, and cuspids, and one piece covering the six front teeth, Avith a foot-piece three-sixteenths of an inch wide, resting on the plate. Make the backings (Fig. 11), same thickness of the plate; cut the edges for foot-pieces in slits, the width of foot-piece, and turn at right-angles, and with an in- strument (I use a worn-out scraper) press into place, under the pins. The front- piece, of course, will lap over backings. the side pieces, on the cuspids. Have the pure gold rolled very thin, cut in small pieces, and lay underneath the foot-piece, and a piece under each pin as it is turned doAvn, pressing the backing snugly to the plate ; Use no borax. AND HAND-BOOK. I prefer soldering in the furnace, the first thing after the fire is made. It can be done, however, : Avith a bellows bloAv-pipe. After cooling, remove the investment, wash thoroughly, and there is no need of boiling in acid. Place on the model, and press into place; see by J the articulator if the position of any of the teeth has been changed, and if so, correct. The only instrument needed for applying the body is a Avax-knife, straight and pointed at one end, and slightly curved and pointed at the other. (Fig. 12.) In addition to this there is required a quill tooth-pick, camel's hair-brush, a stiff' dry brush, a set of boxes, setting one into the other (used by artists), a spatula, a small cloth for absorbing, and a small glass of AATater. The materials, body and gum, are ready pre- pared, and sold at the dental depots. I have always used that made by S. L. Close, New York. Apply the body, Avhich has been moistened so as to be quite thin, Avith the flat end of the instru- ment to the outside; beginning at one end, Avork it thoroughly under and around the teeth, by jarring ; then absorbing Avith the cloth, apply more, after having thickened it someAvhat; continue this pro- cess of jarring and absorbing, then packing hard; Avhen built up sufficiently, dry partially over the gas or lamp, contouring the gums and trimming around the necks of the teeth. Then apply to the palatal surface in the same manner Avith the curved end of the instrument, but thin; brush all particles from the teeth or plate; place on a slide and run into the furnace gradually on a sheet-iron shelf/ attached to the furnace, occupying perhaps half an 38 student's manual hour, the heat meantime coming up, so that Avhen the case is in the furnace and the muffle closed, there is a baking heat. The proper amount of heat must be judged by the appearance of the body, it having a glossy look; place in a cooling muffle and close, remaining till cool. Care, of course, must be taken not to over-bake. The baking is not easily learned, except through personal instruction, and must be closely AA^atched. It will be found that the body has shrunk, and left crevices, which must be filled up thoroughly, and the surface built up to the proper contour again, and at this stage the ruga? may be formed. The case is again run into the muffle slowly, as before, and baked. After cooling, the gum enamel is applied. This is done Avith the same instrument as the body, but care is required to put on a uniform coat, with proper shadings; and unless properly done, it is liable to curl up from the body. It is baked the same as the body, and Avith the same test. After cooling, file the binding even Avith the enamel, rounding the edge of plate and binding ; file the " doubler " AAdierever it can be reached, and use a small, fine corundum where the file does not reach. Finish with pumice and pine stick and polishing brushes. In making a lower set, do not put on a wire, nor turn the edge, but double the edge \ inch wide all around, and let the material extend to the edge. Repairing is easily done, with a little experience. First invest the entire case \ inch thick in asbestos and plaster, and place in the back of the muffle before lighting the fire, allowing the heat to come up slowly, and the case to remain till red; cool, and remove investment. Grind out the remains of tooth or teeth to be replaced, as also some of the gum, outside and inside; select the teeth (rubber teeth will do), and fit them to their places. If there is but one in a place, it can be held there with the body (which should be of a loAver fusing quality), applied carefully and dried. If there are several teeth, arrange with a little wax, and- then over the ends, and also on one or two adjoining teeth, place AND HAND-BOOK. 39 a thin coating of plaster and asbestos; remove the Avax and pack the body around, quite thin at first, and run the case into the muffle someAvhat more slowly than a new case. It will not require as much heat. After cooling, place enamel where needed, and bake. Fig. 13. CONTINUOUS-GUM FURNACE. 145995 40 student s manual Sometimes the grinding surfaces of the molars and bi- cuspids appear rough after baking; it is from the presence of lime, coming from the secretions of the mouth. Put a slight coating of borax upon them before the second baking. If "blisters" appear, grind into them, and fill with re- pairing body, and enamel over it. For furnace, both the coke, and gas and "hydro- carbon " are being used. I prefer and use the coke furnace. I like a large-sized muffle; it is more convenient to work in. I am using the Boulter furnace, No. 2, made in Philadel- phia. Have a table made three feet square, two feet high, and covered with tAvo layers of brick, enclosed, over which place galvanized iron. If you wish to shut the heat out of the room, have a wire frame made, over sides and top, and setting against the chimney, with a removable front, and holes corresponding Avith the furnace openings, and cover with asbestos felt. (Fig. 13.) Make a socket in the front of the table, in which to support a removable upright, on Avhich to rest a shelf, to place the slide on Avhile running it into the muffle. Lea\7e space around the furnace-pipe, where it enters the chimney, for heat from the outside of the furnace to pass oft'. The muffle should be luted Avith fire-clay only at the front, leaving the rear free, as there will be less danger of its cracking across the middle from shrinkage in a high heat. The clinkers should, from time to time, be removed from the sides of the furnace with a cold-chisel, striking sudden blows, so as not to injure the lining. Tees' Lilliput Furnace I have used often in demonstra- ting. It works nicely; my principal objection to it is that the muffles are small and thin. There is a hydro-carbon furnace, made by Hoskins, Chicago, Avhich some use; the heating arrangement may also be used for a melting furnace, for refining gold, etc. AND HAND-BOOK. 41 The Verrier Gas Furnace is very objectionable for tAvo reasons—its constant liability to " gas " the work, and the lilliputian dimensions of the muffle; some sets could not be put into it. One of the best gas furnaces is Dr. C. H. Land's, (Fig. 14), of Detroit. He claims there is no liability to " gasing " in its use. (Send for illustration and full descriptive circulars Fig.14 DR. LAND'S GAS OR GASOLINE FURNACE. 42 student's manual to Dr. Land, or to The Wilmington Dental Manufacturing Company, Philadelphia.) Since the first edition of this work was published a very simple and excellent gas furnance has been placed on the market, by Drs. Parker & Stodard, of Boston. Instead, how- ever, of the bellows Avhich they use, Dr. Berry, of Milwau- kee, makes use of a cylinder of compressed air. Any One intending to undertake the construction of continuous-gum work had better take instructions of some competent dentist who has had experience in the work, as there are many little details which can only be learned in this way. CHAPTER XV. CAST METAL PLATES. FOR full loAver plates these are extensively used, first, because of the weight, which is a valuable adjunct of lower sets. Then we have metal in contact with the membrane, Avhich is an advantage over rubber, and being a non-shrinking metal (tin and bismuth), cast on a non- shrinking model (plaster and pumice, or sand), furnishes a more perfect fit than by swaging, and as alteration of the margins of lower plates is often necessary, Ave are able to do it without injuring the appearance of the work. The process is as follows: Fill the impression with plaster and pumice, or marble dust, equal parts; remove the impression with care, as it is not as strong as pure plaster; form a wax plate, and double the edge | inch wide, which will have the appearance, Avhen finished, of a " rim;" invest the model in Watts' (Fig. 15) or Weston's flasks, using equal Fig. 15. watts' flask. parts plaster and pumice, or marble dust; Avhen hard, Avarm slightly and remove the wax. Cut gates in the plaster, about fV inch diameter, from the extreme point of each heel, 43 44 STUDENT'S MANUAL opening into the flask gates; apply heat gradually till all moisture has disappeared, evidence of which can be had by holding a hand-mirror OArer the plaster. Then close the flasks, apply the clamp, and pour the metal from an iron spoon. Have a wet cloth at hand, so if there should be a leakage, apply it quickly. When cool, finish with coarse file and sand-paper. Spur the surface with a graver quite deeply. Arrange the teeth as in a rubber set, and attach Avith pink rubber. CHAPTER XVI. VULCANIZED RUBBER. ARRAXGE on the plaster cast a Avax plate,—or Avax and . gutta-percha plate is preferable; arrange a rim of Avax on it, and get a " bite," to shoAV the impression of the loAver teeth and relative position of the jaAvs. If a full upper and loAver, arrange the loAver Avax and trim by the mouth to the right length ; then place the upper and obtain a closure, and Avhile in position make several lines in the Avax; remove and trim and replace to see if the closure is the same each time. It is not necessary to attempt to secure the proper fullness and length in the Avax; this Avill have to be done Avhen arranging the teeth, Avith the patient in the chair, avIiether full or partial cases, as it is only by the mouth that the proper arrangement and expression can be secured. Place the cast and " bite " in an articulator, to retain the relative position of the jaAvs, and aid in arranging the teeth. After arranging the teeth, form the Avax for the gum, so as to restore contour of features, trying in the mouth till patient and dentist are satisfied Avith the result. Invest in the flasks. If it is a full case, invest to the margin of the Avax; smooth the surface, shellac, and oil; place the other half of flask in place, and before turning in the plaster, spread some of it with a knife over the surfaces of the teeth, so as to be sure it will fill all spaces betAAreen, then turn in a portion of the remainder, and jar, so as to be rid of air-bubbles. To remove the Avax, place in pan of cold water over the gas, and as soon as it begins to boil remove and separate, and it Avill be found, usually, that the Avax can be easily removed. Then, to clean thoroughly, dash hot Avater 45 46 student's manual upon it; cut narrow gates one-half inch apart all around, and scrape the entire surface slightly to insure closure of flasks. To pack, place the pieces of rubber on a plate of tin or zinc placed over a pan of hot water. If you Avould be specially accurate of the amount of rubber, measure as follows: Have a glass test-tube, or some similar utensil; save the Avax, roll it up and put it in the tube, filling Avith water carefully; remove the Avax and in its place put the rubber, till the water is at the top again, and then add a little for excess. Observe, Avhen waxing up, whether one side requires more material than another, and bear this in mind in pack- ing. Pack small pieces behind the teeth, and then use strips, and one piece sufficient in size to cover the palate. For rubber, the red, colored with bisulphide of mercury, is objectionable; serious results have sometimes followed its use. The black and the maroon are free from deleterious substances. For the surface of the gums use the pink. The color of this is improved by bleaching Avith alcohol in a glass jar exposed to the sun for half an hour or more. The palatal surface should be covered with tin foil; cut a piece the proper size, and Avith a cloth, or tissue paper, rub it to the cast, and it Avill adhere sufficiently. Then slightly coat with soap, to prevent its adhering to the rubber when ATulcanized. Put the flasks together, and place in the press, immersing both in the hot AArater; bring gradually together. If yon have any doubts of a lack of rubber, open and examine (having placed a piece of cloth over the rubber so it will not adhere to the foil in opening), for though there may be enough it may be unequally distributed. Instead of using the bolts to hold the flask, the " spring- clamp " is preferable. As to vulcanizers, you can take your choice. Some are more easily adjusted and handled than others. A vulcanizer arranged with a steam gauge is more reliable than one with thermometer attached. The Gartrell Gas Regulator and AND HAND-BOOK. 47 Steam Gauge, furnished by The Wilmington Dental Manu- facturing Company, I like very much. If the rubber is very thick, the heat should be applied more sloAvly than with thin rubber, to avoid its becoming porous. The black rubber requires loAver temperature and longer time. In fact, in this way all rubber is stronger, so that instead of vulcanizing at three hundred and tAventy degrees for forty-five or fifty-five minutes, two hundred and eighty degrees to three hundred degrees for two hours pro- duces tougher rubber. On opening the flasks, try the rubber by breaking off a gate, to see if it is hard enough. With coarse file, shape the margins and surface of gums ; then use the large bur for the lingual surface, using the calipers to avoid making it too thin, yet give the patient all the space possible for the tongue, without sacrificing strength. Also, by use of the large bur festoon around necks of the teeth. With thin, sharp chisel, trim around the necks of the teeth, and, Avith small sharp points, be- tween. Use the round scraper for the palatal surface. Sand- paper (ISTo. 0 or 00) thoroughly, and finish Avith pumice, either Avith a pine stick in the hand, felt cone, or both, and finally with small, soft brush wheels. A partial case, where there is no rubber outside the gums, should be invested in the deep part of the flask, cover- ing the teeth entirely. D CHAPTER XVII. celluloid. THE process for celluloid is similar to that for rubber, but requiring a different flask. Instead of packing a soft material in the molds, to be hardened, a hard material is placed between, to be softened and pressed into place. The celluloid is prepared in blanks, of various sizes and shapes. When the case is ready for the blank, it is placed between, sometimes altering by filing, or heating in boiling water and bending, so as to bring into better shape for the flasks. There are two methods of applying heat, dry and steam. There are various appliances for this purpose. The latest and most perfect is the New Mode Heater, Avhere, though steam is used, the case is in a dry air chamber. Finish the same as rubber. It should never be allowed to remain out of the mouth Avithout being placed in Avater, as it has a tendency to warp. The cheaper heaters for this work are not desirable, and have long since been abandoned by most of those Avho have used them. I have given celluloid six years thorough trial, and am convinced it is the Avorst material used in the mouth. 48 CHAPTER XVIII. REPAIRING. GOLD OR SILVER. REMOVE the remains of the broken tooth and the back- ing. Select a tooth and wax into place; insert in plaster and sand, or marble dust, and put on the backing. These repair cases should be heated slowly, taking an hour for the purpose, then solder. Cool off sloAAiy, and it will be a rare occurrence that a tooth is cracked. If the plate has cracked and spread, let it remain in that condition, as it has followed a change in the gums. Lay a piece of Avet tissue paper over the crack on the under side, so the plaster will not get into the crack. Scrape the surface of the plate; invest and fit a small piece of plate over the crack; lay the solder in small pieces along the sides; heat and solder. If your solder is right and you give it proper heat, it Avill not only flow under the piece of plate, but also into the crack. To solder a gold plate in repairing, Avhere there are rub- ber attachments, take a turnip or potato and enclose in it the rubber portions, and proceed to solder the tooth, clasp, or crack. RUBBER. Remove the broken tooth, and file aAvay the rubber back of it; select a tooth that Avill go into the impression of the neck of the former tooth, and Avax into place; insert in the deep half of the flask; remove the wax, scrape the surface of the rubber, and, Avith a hot spatula, spread rubber on the surface. Then pack the balance, and complete the invest- ment and Arulcanize. 49 50 STUDENT'S MANUAL If the plate is cracked, cut away the length of the break, from each side, £ inch, and nearly the thickness of the plate at the break. If the break has extended to the outer edge, under the teeth, remove one of the teeth, cut aAvay a portion of the break, wax the tooth into place, and wax over the break, invest, and wash out all the Avax, and, if necessary, remove the tooth, and pack the rubber back of it, then re- place and pack elseAvhere, and vulcanize. In repairing a partial lower, carefully place the fractured ends together and Avax into place ; insert and cut away the rubber for a space of I inch each side of the fracture, and at the fracture to its full depth ; pack as before described. CELLULOID. Prepare as in rubber, and, after removing the wax, scrape the surface, apply camphor, and place a piece of celluloid, wet with the camphor, where needed, and put into the press; apply a strong heat, and press into place. CHAPTER XIX. SELECTION AND ARRANGEMENT OF TEETH. IX no department of dental practice is more skill, judg- ment, and experience needed than in this ; and in none is there so little manifest, if we judge from the average artificial dentures in wear, especially full sets. Dr. W. W. Allport, of Chicago, well expressed it in an address before the Boston Academy of Dental Science: " He who has but moderate ideas of symmetry, harmony of expression, and color, is constantly pained by the lack of that artistic selection and arrangement of artificial teeth which serve to restore to the face the shape and expression left on it by the Creator, the absence of which in artificial dentures stamps him, who should be an artist, an artisan, as a mere mechanic—a libeler of the soul—a deformer of the human face divine. That mechanical dentistry should have very largely fallen into the hands of this inferior class of practitioners, will hardly be wondered at by those who have watched the history of this branch of the practice. For so simple are the modes of attaining tolerable mechanical results, with the methods noAV usually employed in this department, by the use of rubber plates and ' gum sections,' that one possessing & high order of appropriate talent is seldom found devoting much time to it." It is difficult to giAre oral or Avritten instruction on this subject; it requires the clinic, often repeated. As the dentist is constantly at work upon the natural teeth, he should study the subject from that standpoint. The indiscriminate use of " gum sections " is largely responsible for many failures, for it is impossible to secure proper results, in all respects, where they are used. Their .appearance is sometimes an outrage on the human face. 51 52 student's manual I long ago ceased to use them, using instead, plain teeth and pink rubber gums. The question is asked by dentists : " Suppose your patient says she Avants a more natural-looking gum? " I tell her it is better to sacrifice somewhat on the color of the gum than so much in other respects, by the use of gum teeth. I never yet have had to change the teeth in such cases. I arrange the teeth and a wax gum, and tell the patient that the wax will be replaced with a gum, but do not say Avhat kind, and they seldom speak of it afterwards. If there is prominence of the upper jaw and short lip, the Avorst class of cases to deal Avith, the gum teeth are utterly out of place, because while a porcelain gum is a neces- sity, it must be very thin, high, and seamless. In these, the continuous-gum process is the only available one, as by it a thin gum can be secured and yet be strong, because it is baked to the plate. In selecting teeth, if there are teeth remaining in the jaw, there is little difficulty, because it is only necessary to match, in shape and color, these natural teeth. Do not use gum teeth unless it is absolutely necessary. If it is, look for teeth with the gums extending but a short distance below the neck of the tooth, as the natural gum has receded and needs to be matched in this respect. The corners of the gum on a single tooth should be rounded and ground, to match nicely the natural gum. Generally there is not room for the plate behind the gum, without making the gum too thin, or preventing the setting of the gum far enough in to match the natural gum. The gum as well as the teeth should match in shade. As far as possible, select front teeth Avith the pins per- pendicular; occasionally the bicuspids and molars require " cross " pins. In partial rubber sets, the rubber can often be used for gums, and when possible, it is better. If the bite is so close in front, there is not room for the AND HAND-BOOK. 53 thick rubber teeth, select a plate tooth, and solder a backing,, with a foot-piece that can be enclosed in the rubber. If the bite is very close over the lower posterior teeth, make use of cuspids, or else what are known as " crown " teeth, instead of bicuspids and molars, and have the lower teeth close on a rubber surface. In case of a gold plate, Avhen this condition of things exists, attach the teeth with rubber, or make a shoulder of gold to bite on. In the selection of teeth for full upper sets, the lower are usually a guide in color and size. I say in size, in this Avay: the upper teeth, when properly articulated, should be so ar- ranged that the cusp of the lower cuspid is between the upper lateral and cuspid ; so that upper teeth which do this, it may safely be assumed, are the size of the natural ones. This allows of the interlocking of the bicuspids, as nature arranges for. If, in the preparation of the mouth, there should be extracted a central incisor, be sure to retain it as a guide in the selection of artificial teeth. The patient will sometimes insist that you have selected teeth larger than the natural. I have often in this Avay shoAvn patients that I have selected teeth no larger, and sometimes a trifle narroAV, when they have supposed their new teeth were larger. There is a great tendency to use small and white teeth, Avhich often give an insignificant expression to the mouth, the patient looking as though Avearing their deciduous teeth. I sometimes remind them that it is time they had shed their "baby" teeth. The dentist must be guided by the general appearance of the natural teeth. The study of physiognomy and tem- perament is of great value in deciding what to do when all the natural teeth are missing. As a guide, I have prepared the folloAving table, abbreviated from the elaborate one of Dr. J. Foster Flagg's, Avhich will be found serviceable. Of course, there are variations from these, as there are combina- tions of temperament. HAIR. EYES. LIPS. TEETH,SHAPE BTLTOUS. SANGUINEOUS. Tall, angular, Square-built. Full, firmly Hounded, Robust. NERVOUS. Delicate, Slightly built. CRANIAL CONTOUR... Angular, high ; pounded and Full. Oval. cheek hones. Black and curling. Golden to light : Brown, wavy, chestnut. fine. Black. Blue. Dark brown. Rudd}r and full. Fine, grayish pink. lymphatic. Bulky, clumsy. Flat-faced. Coarse, straight, drab. Gray. Large, Brownish, Purple. Large, longer than Well propor- | Long wide, tioned, curved andi aimond.suaped. Angular. Large, not shapely. Brownish, TEETH, COLOR......j Yellow, I Opaque. rounded. Straw, yellow, translucent. Pearl-blue, translucent. Large, width predomi- nating. Dark gray, opaque. AND HAND-BOOK. OD All teeth are variably yellow at the neck (some very slightly). They become darker from the cuspids to the pos- terior. The cuspids are ahvays more yelloAv than the incis- ors, and the bicuspids and molars darker still. This rule, hoAvever, is not followed by the manufacturers, but the dentist, in matching partial sets, at least, should see that the posterior teeth are the darker. Usually, there is more yelloAv in the loAver than in the upper teeth. It is not, hoAvever, ahvays possible to secure just the shade required from the stock to Avhich you have access; neither is it the case in the large stocks. This is partly be- cause so many dentists are indifferent, or do not know what is proper. If dentists had more cultivated tastes and were more particular, so as to make an imperative demand for better shaded and shaped teeth, they Avould speedily be made. There are certain general directions that may be given for the arrangement of the teeth. Be careful not to make the teeth too short. This is a very common failure, patients often appearing as though they had no teeth. Remember that when the teeth have been extracted many years, and too short teeth have been worn, the lips contract, consequently make the teeth longer than you othenvise Avould, as the muscles will lengthen again. Always arrange the upper teeth first, in full sets, as they give the character to the face. Arrange the ten anterior teeth, so that if placed upon a flat surface they will rest evenly: arrange the molars shorter and on an oblique line. The loAver teeth arranged to these, Avill shoAV, upon a flat surface, only the incisors and second molars touching. This arrangement, is, of course, nature's, and Avill effectually pre- vent the lower denture sliding forward, as is sometimes the case. In all cases Avhere the cuspids have been missing for a year there is absolute necessity for the plate to be higher, (Fig. 16) and the gum fuller, than elseAvhere, so as to restore the contour of the lips. 56 STUDENT S MANUAL Fig.' 16. If the upper lip is short, the natural teeth show much more than Avhen it is long. Some persons can scarcely cover the natural teeth; they shoAV the Avhole length of teeth and much of the gum. If the upper lip is very long, the natural teeth do not show at all. The loAver teeth do not generally shoAV as much as the upper; seldom are the gums seen. Rarely alloAv a drawn-in appearance to the upper teeth. It sometimes occurs in the natural organs, but is usually a deformity, like some other irregularities, not to be followed. The teeth, as a rule, should stand perpendicular, avoiding either an inward or an outward slant. Of the six front teeth, the cuspids should generally be the most prominent, espe- cially at the neck. The bicuspids should drop inside a trifle of the range of the cuspids, and from there back be nearly on a straight line. There are various irregularities of the natural teeth % such as over or under-lapping of the laterals and centrals. If it is a pointed jaAV, and the loAver front teeth are con- tracted, the centrals should be the most prominent, and the laterals dropping back a little, and the cuspids still more. If the arch is broad, the laterals should overlap, if not in a line with the centrals. We should set the teeth apart in some mouths Avhere there is plenty of room, and close or even lapping Avhen there is a small arch, and in some mouths make the teeth quite irregular, if it is a person of large build, especially if his loAver teeth are croAvdedand irregular. AND HAND-BOOK. 57 Xever consider it necessary to make the teeth absolutely ugly to look natural. For a lady of regular features, irregularities, except slight ones, are to be avoided. Nothing more than the set- ting apart, or slight tipping of a lateral, is needed. Where both sets are being inserted, they should always be arranged together. In the arrangement of the loAver teeth, after the length is decided on, the Avidth of the six anterior teeth should be such as to bring them Avithin the proper compass for a correct articulation; that is, so the point of the lower cuspid comes betAveen the upper lateral and cuspid. Then there is no difficulty in securing a correct apposition of the bicuspids and molars. To do this, it is usually necessary to crowd the lower teeth, unless the uppers are large. The over-lapping and irregularity of the loAver teeth are generally in the line of nature, and always give a natural appearance. Of all places, gum sections are most out of place on the lower jaw. The necessity of setting the teeth sufficiently in over the ridge makes it generally impossible to get them there Avithout grinding away the gum too much; Avith them it is next to impossible to give the proper arrangement of the teeth, so as to secure a correct expression and articula- tion. If gum sections are used on the upper jaw, they should at least be discarded on the loAver. The utmost stress must be laid on the correct closure of the teeth. There are more failures arising from this cause than from misfits. The jaAvs should close so as not to dis- turb the position of the plates, otherAvise there is trouble. It should be borne in mind that whenever the patient SAval- lows, as they are constantly doing, without thought of it, the jaAvs close tightly, and this, of course, displaces the plates if the teeth are not properly articulated. A common fault is the interference of the anterior teeth. When they strike before the posterior teeth do, the upper plate is croAvded forward and down from the rear. 58 student's manual The six anterior should never meet, except Avhere men tioned later. When, as is usually the case, the upper close outside the lower, they should drop not more than £ inch below the ends of the lower, and there should be at least | inch space horizontal between them, and even then, in time, by the settling of the gums, they will come together, and need grinding to prevent strong pressure. If it is a protruding lower jaw, let the upper teeth be arranged over the ends, but not meeting; the back teeth being long enough to take the pressure off the front teeth. In excessive prominence of the lower teeth, arrange the ends of the upper teeth inside of the lower, as nature had done; then if they do meet slightly, the pressure will be favorable to the upper. The posterior upper teeth should never be allowed to drop on an inclined plane from the cuspid to the molar. The expression is bad, and the possible advantage claimed by some in use is not sufficient compensation. The manner in Avhich the surfaces of the bicuspids meet is of importance. The posterior side or slope of the lower bi- cuspid should press on the anterior side of the upper. The lower anterior teeth should be set well in over the ridge, otherwise there is undue prominence of the lower lip. The pressure should fall mainly on the bicuspids and first molars, not allowing the second molars to meet, because Avhen there shall be a closer approximation of the jaws by the settling of the gums, these teeth will feel the pressure excessively, and there Avill be irritation of the membrane and crowding forward of the plates; this Avill be felt specially on the lower jaw, and require the shortening of these molars. If there are wisdom teeth standing alone on the lower jaw, they are usually inclined forward, so the surface is often at an angle of 45°. They should be avoided in arrang- ing the upper teeth, for if they meet it Avill result in crowd- ing the plate forward, and the difficulty will constantly increase. AND HAND-BOOK. 59 A difficult condition of things is met when a full upper set is inserted, and there remains on the lower jaw the six anterior teeth, and on one side one, or, perhaps two bicuspids, and nothing on the other. Here there is nothing to counter- balance the pressure on these bicuspids. The insertion of partial lower would be of no value, for they would soon yield to pressure; but, if these bicuspids were extracted, and on both sides Avere artificial teeth, the difficulty would be removed ; the patient would have a good masticating sur- face, and no displacement of the plate. In such instances the best interests of the patient should be consulted, and not mere sentiment about extracting sound teeth. If all the teeth remain on one side and none on the other, make a virtue of necessity, as there is so much involved in the sacrifice. Build a biting surface for the lower cuspid ; if it is a rubber plate, insert a small piece of a tooth, with the pins in it, in the rubber back of the upper cuspid. The articulation of teeth is sometimes very difficult. Great care must be exercised that there is no one tooth nor one side meeting before the other. When the lower anterior teeth are much longer than the bicuspids, shortening of them is always desirable, or some- times building up these bicuspids or placing croAvns on them is essential. If this is not done, make the upper bicuspids sufficiently long to throw the jaws apart, so that the upper will not close too far below the ends of the lower. If the surfaces of the bicuspids are inclined planes, grind, if possible, so as to make a square biting surface. The general position of the lower posterior teeth should be such that the force of the pressure is toward the center of the upper ridge, and not outward. It is usually more difficult to properly arrange the lower set than the upper. The two sets should always be arranged together, then finish one and try in, and correct any faults arising from the two sets in Avax arranged at once. In ninety-five per cent, of mouths, there is more depres- •60 student's manual sion at the left side in the region of the cuspids than at the right, so that the teeth need to be extended lower from the plate, to secure a proper range with the lips ; and also more thickening of the artificial gum, to restore the contour of the lip. A valuable article upon "Typical Tooth Forms," by Dr. E. T. Starr, appeared in the Cosmos for August, 1889, from which Ave quote the folloAving suggestive paragraphs. They will be found a great aid in arranging teeth, and we -advise their careful study. " Some years since, Dr. W. G. A. Bonwill read a paper be- fore the Odontological Society of Pennsylvania, in Avhich he made the following:; claims: " That the loAver human jaAV forms an equilateral triangle, the base of which is the distance from center to center of the •condyles, and the sides the distance from these points to the median line of the inferior incisors, the average measurement of the sides of the triangle being about four inches. " That in ninety-five per cent, of cases the superior jaAV projects beyond the inferior, the depth of the underbite vary- ing from three-eighths to one-sixteenth of an inch, and that in not more than five per cent, of articulations do the incis- ors come directly together. " That the ramus has a definite curvature, and that the depth of the underbite and the length of the cusps of the bicuspids and molars correspond thereAvith. " That the teeth in the arch posterior to the cuspids are almost directly in a straight line toAvard the center of the condyles. " The substantial correctness of these conclusions appears probable. " Plate III, Avhich is a perspective view of the occluding surfaces of the set of natural teeth illustrated in Plates I and II, shows the equilateral triangular basis of the inferior jaw. A-B shows the width of the base or hinge of the jaw ; A-C and B-C show the length of the line from the condyloid pro- cess to the center of the curve of the inferior incisors. AND HAND-BOOK. 61 The Superior and Inferior Jaws in Occlusion. PLATE I.* The Superior and Inferior Jaws Open. Copyright, 1889, by E. T. Starr. 62 student's manual PLATE III * * Copyright, 1889, by E. T. Starr AND HAND-BOOK. 63 " The centers of the tips of the anterior superior teeth are in the arc of a circle, the center of which is found by measur- ing from betAveen the centrals along the median line of the mouth a distance equal to the combined widths of the supe- rior central, lateral, and cuspid, taken at the lines of greatest breadth. A line, at right angles to the median line of the head, through the center of this circle, which is knoAvn as the circle of the mouth, Avill pass through the centers of the second bicuspids; and a similar line, parallel to the first, through the posterior periphery of the circle, Avill pass through the posterior edges of the second molars. " The cuspid and the anterior buccal cusp of the first molar, it Avill be remembered, have been previously spoken of as forming respectively the primary and secondary springs of the superior arch ; that is, they mark decided changes in its direction. In Plate III the superior central, lateral, and cuspid, as has been said, lie in the arc of the circle of the mouth. At the cuspid the direction changes ; the buccal faces of the teeth betAveen the cuspid and the anterior buccal cusp of the first molar lie in a straight line. At this latter point, which is usually prominent, the arch is again deflected slightlv inward. " In the inferior jaAV there is no secondary spring of the arch. The four incisors are more nearly in a straight line than their corresponding teeth in the superior jaAV. The direction changes sharply at the cuspid, and thence forms a continuous, gentle curve along the buccal faces of the teeth, though the lingual faces of the posterior teeth approach very closely to a straight line. (These latter points do not appear in Plate III, as the teeth Avere drawn in position to give a perspective instead of an exact face-vieAv.)" In order to make practical these suggestions have differ- ent sizes of tin circles, and select, by use of dividers, one Avhose radius is the Avidth of the central, lateral and cuspid teeth of the set you have selected for the case in hand. E CHAPTER XX. TEMPORARY WORK. PATIEXTS dislike to go very long Avithout teeth, and it is unnecessary. Long experience has satisfied me. that, as a rule, the teeth should be inserted within forty-eight hours after extraction, taking the impression as soon as the bleeding has stopped, and before the gums haA^e swollen. When the front teeth or their remains have just been removed, I make use of the sockets to insert, for a short distance, the necks of the artificial teeth, giving, of course, a natural appearance to them. There is rarely room for an artificial gum in temporary cases, and then only that furnished by the rubber plate being allowed to cover the alveolar ridge. On the lower jaAV, if many teeth have been extracted, it is better to wait till the gums are healed; but if the patient is desirous of having them at once, make them; if the re- mains of the front teeth have just been removed, set, as in the upper, the necks of the teeth into the sockets. It is seldom possible to cover the outside of the a Areolar ridge with the plate, without projecting the lip. Injury comes to the ridge by wearing the temporary plates too long. It causes excessive absorption where it presses too hard, and is quite annoying. The patient should visit the dentist occasionally that changes may be made in the plate or grinding surfaces of the teeth, as the gums settle. 64 CHAPTER XXI. ADJUSTMENT IN THE MOUTH. AFTER the work is completed, be careful to adjust it in . the mouth so as to leave as favorable an impression as possible. If it is a clasp plate, see that the clasps spring into place so as to hold, and yet not be injuriously tight. See that the teeth are articulated in partial sets, so that the pressure is thrown on the natural organs. In adjusting a full set the greatest care must be taken to see that the articulation is correct. Say to the patient: If you find the plate hurts you, call soon and have the pressure relieved, for it is not necessary to suffer; relief should be afforded at once. It is advisable to see the patient in a few days, to be sure that the articulation is correct. Too much stress cannot be laid on this point. " Articulating paper" is very useful to indicate when grinding is necessary. The ordinary black transfer paper will ansAver, although rather thin. If there seems to be undue pressure at any spot on the hard palate, it may be located upon the plate, by spreading a little moistened rouge upon the spot and pressing the plate into place. There are mouths where all the conditions are favorable, so that it is easy to secure results satisfactory to the patient as Avell as to yourself. There are mouths where all the con- ditions are unfavorable, and after the dentist has done all that care, skill, and experience can accomplish, the patient Avill complain, and wonder why the teeth do not work as satisfactorily as Xeighbor Blank's. It is often because the conditions of the mouth are entirely different or unfavorable 65 66 STUDENT'S MANUAL to the best results. The only thing is to impress the im- portance of patience and constant use of the teeth. Time and perseverance Avill accomplish Avonders. A feAv hints may be given on the use of artificial teeth, as, for instance, in biting an apple; if the teeth are used as the natural teeth are, they are liable to be thrown down from behind. The new teeth must be pressed against in biting. In masticating,, if the food is all placed on one side, the leverage is such that the plate is displaced; and yet, in time, the patient will learn to eat on one side; but at first divide, and with the tongue place the food on both sides. CHAPTER XXII. THE ANGLE SYSTEM OF REGULATION. AND RETENTION OF TEETH. EDWARD H. ANGLE, D.D.S., PROFESSOR OF HISTOLOGY AND LECTURER ON COMPARATIVE ANATOMY AND ORTHODONTIA IN THE DENTAL DEPARTMENT OF THE UNIVERSITY OF MINNESOTA. SIXCE the publication of the first edition of this work, experience in the treatment of a large number of cases has resulted in the subjection of these appliances many times to the most seA^ere tests. As a result of this, several modifications haATe been developed, both in the application as Avell as the proportions of the different parts, together with an entire change in the material from Avhich the appli- ances are constructed. The little pipes Avere originally con- structed from Avire containing seams. They are now made seamless, which is an advantage. It is belieA^ed that the set of appliances shown in Fig. 17 is very nearly faultless. Fig. 17. angle's appliances. It is not my intention at this time to give a full and complete treatise on Orthodontia, but rather to give my own 67 68 STUDENT S MANUAL method of accomplishing the different movements in the correct adjustment of malposed teeth, believing that most practitioners will succeed far better by adopting one method and thoroughly familiarizing themselves Avith the principles of the same, than they Avill by but a general understanding of the almost innumerable methods and appliances which have been brought out from time to time. To those who Avish to pursue the subject as to the Eti- ology, together Avith the history of methods and appliances in general, I would recommend the excellent works on the subject by Drs. Guilford and Kingsley. In studying the construction and application of any system having for its object the treatment of dental irregu- larities, the fundamental principles will be more easily un- derstood if we remember the movements of the teeth in regulating are limited to one or more of the folloAving: Forward in line of arch; backward in line of arch; from without, inward; from within, outward; rotation, and occasionally elongation or depression. The physiological principles governing all these movements are the same, so that by understanding the principles governing one, we may comprehend all. In applying force to a tooth, it should be direct, and sufficient to accomplish the desired movement as rapidly as is consistent with the physiological law governing the absorption of bone in each case. This law varies so greatly with different individuals, and at different ages, that no fixed rate, or even approximate rate, can ever be established. The judgment of the operator must determine. In no instance should the pressure exerted be great enough to occasion pain; if so, the normal rate of absorp- tion is interfered with. A very safe rule to apply, whether the pressure be con- stant or irregular, is to see that it does in no instance exceed a snug feeling. I am convinced that this feeling is the true indication of the proper amount of force. AND HAND-BOOK. 69 Another very important principle Avhich should ahvays be borne in mind Avhile performing the movements of a tooth is, that pressure should never be wholly relinquished. The movement of a tooth may be arrested as often as necessary, but never allowed, by reason of removal of pres- sure, to spring backward, thus interfering with the process of repair. I am convinced that disregarding this principle (as has usually been necessary in the ordinary regulating appliances, by the reason of the faulty principles on Avhich their con- struction has been based, necessitating their frequent removal for purposes of modification and cleansing) has been the occasion of nearly all the pain and soreness in regulating. The result of this in many cases has been discourage- ment on the part of the patient, and much annoyance and frequent failure on that of the operator. The movement of a tooth, if intelligently accomplished, should be painless. Another very important principle to be remembered is, that support and perfect rest are essential to a tooth after it has been moved into the desired position. Any appliance for retaining a tooth Avhich necessitates its frequent removal should never be used. Again, a retain- ing appliance should be so delicate that it may be worn Avithout inconvenience to the patient, until perfect firmness has been established, and should never be under the control of the patient. It may be needless to remark that a tooth so retained will become firm in its new position much more speedily than if subjected to occasional disturbances. It is believed the folloAving system of treating dental irregulari- ties enables the intelligent operator to easily fulfill the re- quirements so far enumerated. In deciding upon a proper course of treatment in any given case, much care and judgment should ahvays be exer- cised, beside a careful study of the features and the due con- sideration of the probable modifying effects of the proposed changes, the establishment of correct occlusion, etc. 70 student's manual A valuable assistant Avill always be found by first obtain- ing careful and accurate models of both jaws, and correctly articulating the same. Such models not only assist in forming a basis for cor- rectly establishing the proper line of operation, but are exceedingly valuable as reference during the AAdiole course of treatment, for, from such models accurate measurements may be taken from time to time, and comparisons may be made Avith the teeth as the case progresses. In this way Ave may not only judge of the exact speed of the moving teeth, but unfavorable mo\Tements of the anchor teeth may be detected. In order that these models may be of any value they must not only accurately shoAV the positions of the teeth and cusps, but they must also indicate the rugte, gums and as much of the roots and positions of the same as is indicated by the shape of the gums and ah^eoli up to the point where the attachments of the muscles render obscure the further shape of the jaw. From the large number of imperfect models that I have received from dentists, I am of the opinion that the value of correct models is not sufficiently appreciated. After trying all kinds of impression materials and dif- ferent methods of taking impressions, I am Avell satisfied that the best material is plaster,* and it should be used as follows: In the first place, the impression cups for sale at the different depots are all incorrect and ill adapted to the purpose of obtaining impressions of a jaw containing full dentures, for the reason that they are all intended for obtain- ing impressions of edentulous jaAvs. The rim of these cups, as well as the proportions covering the palatine process, are entirely too low; they should be much higher. * Since writing the above I have been experimenting with Teague's Im- pression Compound, a substance similar to plaster, which is probably in some respects superior. AND HAND-BOOK. 71 By obtaining a feAv sizes of the cups designed by the author, as represented in Fig. 18, the difficulty of taking Fig. 18. impression cups for irregularities. impressions high up or Ioav doAvn (depending upon Avhether it be the upper or loAver jaw) is Avholly obviated. When a cup suitable to the case has been selected, it should be slightly oiled, or coated with a film of fine castile soap, Avhich can be easily accomplished by moistening a small pledget of clean cotton in water, rubbing it over a piece of soap, and then over the cup. It is also %vell to coat the teeth in the same manner. When the impression plaster has been mixed to the usual consistency, and distributed in the cups, nearly as it 72 student's manual should appear after the impression is taken, and the patient, provided Avith a clean towel about the neck, has been in- structed to sit upright, the mouth is opened and the cup inserted. The head should be someAvhat throAvn forAvard to prevent the plaster from falling into the throat. The cup should be pushed up first at the heel, then the lips raised, and the anterior part of the cup forced Avell up into position ; then the lips should be draAvn down OATer the edge of the cup, and a slight pressure exerted from the outside in order to force the plaster well up against the muscles. The plaster should be alloAved to become hard and thoroughly set, after which the cup and all surplus pieces of plaster should be carefully removed, leaving the impression still in the mouth. With a blade of a penknife cut two grooves in the impres- sion, the positions of the grooves being parallel to the lines of axes of the cuspid teeth. These grooves should be quite deep, but not entirely through the impression to the gums or crowns. This being done, the point of the penknife should be in- serted in one of the grooves, and Avith a quick pry, the exter- nal plate of plaster betAveen the grooves is readily removed. The plates at the sides can noAv be readily broken outward betAveen the thumb and finger, the line of fracture will follow the cutting edges of the teeth, then the large piece of plaster covering the roof of the mouth is readily worked loose and removed in one piece. If the operation has been carefully performed, the impression Avill consist of but four pieces. After drying a feAV moments, they are readily replaced in their proper positions, in the order in Avhich they were removed, and secured by wax, or, better still, moistening the edges of the fracture Avith celluloid dissolved in ether, as suggested by Dr. Van Duzee. Never attempt to re-unite the pieces by placing in cups. AND HAND-BOOK. 73 The impression should noAv appear as shown in Fig. 19. Fig. 19. impression re-united. Xot later than one-half hour after the impression has been taken, the inside should be thoroughly coated Avith shellac varnish ; at the expiration of another half hour, again coated with sandarac varnish, and at the end of still another half hour, it should be very carefully filled with plaster and turned upside down on a glass slab. After the plaster is thoroughly set, the pieces of the impression may usually be readily separated in the same order in Avhich they Avere removed from the mouth. The model can noAv be trimmed, and not only will there be a surface as smooth as the most finely polished mar- ble, but each cusp, and all the interdental spaces, as well as the rugae, and even the minute " stipples" of the gum will be most accurately and beautifully shoAvn. The models should now be neatly labeled, and will serve all the purposes of study and reference already enumerated. We noAv come to another most important principle, 74 student's manual "SS^t-J '-K^'O*^ stationary anchorage. which should be remembered in the movement of a tooth; that is, that correct or stationary anchorage should be secured. Teeth that have been selected as anchorage should be attached to in such manner that tipping and consequent movement Avould be impossible, or if moA^ement of such a tooth does take place the anchorage should be so rigid that the tooth must be dragged bodily through the alveolus, the apices of the root moving fully as much as the crown. This principle is Avell illustrated Fig. 20. in Fig. 20, in which the anchor-teeth are banded, and a pipe or sheath through Avhich the screAV pulls is rigidly attached by means of solder, as the bands on the anchor-teeth are firmly cemented. It Avill be seen that perfect anchorage is established and consequent tipping of the same is thereby rendered impossible. The dotted lines in the diagram indicate the moATements Avhich must take place. Fig. yig. 21. 21 shoAvs the same principle Avhere the motion is pushing in- stead of pulling. The base of the jack-screAv in this case is soldered to the band. It will be readily compre- hended hoAv greatly anchorage is increased over the old method, when advantage is taken of this method of anchorage. Figure 17, Angle's Appliances, shows the simple appli- ances from Avhich all the various combinations used in the method may be made. " A " is a large traction screw in- cased in its accompanying tube, and used for pulling Avhere the resistance is great. " B " is a smaller traction screw, used in the same way where the resistance is slight, or where from any reason a delicate appliance is desired. " C " and if. " '-.-t Zi'*- >' lateral movement. AND HAND-BOOK. /D " D " are tubes Avhich are soldered to bands placed upon the teeth to be moved, into Avhich the ends of the traction screw are hooked. "J " is a jack screAv, used for pushing, the end of Avhich is beaten flat. "E " is an extra piece of tubing, by means of Avhich a longer jack screAv can be made. " F " are coils of band material. " G " is a gold Avire used in re- taining the teeth after they have been moved into the desired positions ; also, to assist in securing an anchorage in some cases; and " R " are small retaining tubes designed to be soldered to bands into AAThich the retaining wire accurately fits. " L " are piano-wire levers of Ararying sizes, giving different degrees of poAver. It Avill thus be seen that the appliances are very simple, and few in number, they being limited practically to three, viz.: the lever for rotating, the screw for pushing, and the traction screw for pulling, the other pieces being for the pur- pose of securing attachments, and, aside from the advantages of simplicity, efficiency and cleanliness, stationary anchor- age, non-relinquishment of pressure, and firm retention may be easily accomplished by their intelligent application. As it Avill be seen that the Magill band (Fig. 22) plays an important part in attaching the different parts of the appli- ances to the teeth, I Avill here describe the quickest, easiest, and most accurate Avay of making and setting these bands. First, the rubber dam should be slipped over the tooth to be banded, and at least one more on each side, and it is usually better to include all the teeth to Avhich the appliance is being adjusted. The surface of the tooth to be banded is then carefully cleansed by means of a pledget of cotton moistened in alcohol or ether. A loop of the band material is then slipped over the tooth. I prefer German silver to any other metal, on account of its great strength ; it mav be rolled to extreme thinness, thereby occupying a small amount of space. The ends should iioav be grasped close to the tooth Avith a pair of closely-fitting, flat-nosed pliers, and the band drawn tightly 76 STUDENT s manual around the tooth, a strong burnisher being applied at the same time, to make it conform still further to the shape of the tooth; remove the band, Avhich noAv presents the appear- ance shown in Fig. 22. Place a small bit of silver or gold Fig. 22. solder and borax at the junction, and carry the band in contact Avith the flame of the soldering-lamp. After it is soldered, clip the ends off, and the band is now ready for any at- tachment which may be made; after Avhich it is cemented in position on the tooth, being gently driven to place by means of a foot-shaped plugger and small mallet. If the teeth are firmly croAvded together, space may be gained for the band by forcing first a thin spatula between them. We might illustrate, without limit, the different Avays of attaching and operating these appliances in accomplish- ing the movements of the teeth ; but sufficient number of the many modifications of Avhich they are susceptible is here shoAvn to enable the average operator to become sufficiently familiar Avith them to treat all ordinary cases. The movements of rotation of a tooth is accomplished by means of the lever shoAvn at " L," Fig. 17. The tooth is banded in the manner already described. One of the small pipes, " R," Fig. 17, is soldered to the buccal surface of this band, and the band cemented in position upon the tooth ; one end of the rotating lever is inserted into the pipe ; the other is sprung around and latched into a hook soldered to a band encircling a suitable anchor MAGILL BAND. (Greatly Enlarged). Fig 23. ROTATION. tooth. Fig. 23 shows a lateral in- AND HAND-BOOK. 77 <3isor while being rotated by this appliance. It will be seen that a poAverful and constant force is being exerted upon the tooth to he moved. It will also be noticed that the anchor-tooth is re-in- forced by a piece of the gold Avire, "G," Fig. 17, passing through a pipe soldered to the lingual surface of the band; the ends of the gold wire resting upon the lingual surfaces of the first bicuspid and molar. The appliance is shown Frc- 24- in detail in Fig. 24. After- the tooth is in proper po- sition, it is retained by means of a short piece of the gold wire, Avhich ROTATING APPLIANCE IN DETAIL. RETAINER. passes through the tube, and extends upon the central, as seen in Fig. 25. This Avire is kept in place by a small pin, Avhich is tightly fitted in a very small hole drilled through both tube and one side of the Avire, as shoAATn. Fig. 26 shows Fig. 25. two poAverful cuspid teeth Avhile being rotated by this method. It will be seen that the lever may be applied Avith an equal effect upon either the inside or outside of the arch, and in this case one anchor tooth is made to serve as an- chorage for both levers. It is necessary to exercise care and judgment in the use of the poAverful levers. First, the lever should not be alloAved to touch at any point upon the teeth inter- vening betAveen the tooth being rotated and the anchorage, lest the moving tooth be pried outward; second, care should be taken that the moA^ement is not Fig. 26. ROTATION. 78 STUDENT s manual accomplished more rapidly than the absorption of bone takes place, otherAvise the tooth Avill be sprung outward by reason of the external plate of the alveolus Avhich, being thinner, offers less resistance, and will be gradually bent outward. Fig. 27. When the teeth are to be rotated in opposite directions at the same time, as the central incisors, shoAvn in Fig. 27, double rotation may be accom- plished by one appliance. Both double rotation. the teeth are banded, and a tube soldered to each band; one being horizontal and the other vertical. A piece of the lever "L," Fig. 17, is bent at right angles at one end, and then sprung into position, as seen in Fig. 28. The tendency of the Fig. 28. wire to straighten itself will ro- tate both teeth at once. Recent experience has shoAvn that a better way of applying the lever is to at- tach both pipes horizontally, using a double rotation. straight lever, springing and sliding it into the last pipe in the same manner in Avhich a bolt is slid in position in fastening a door. The piano wire used in making this lever should never be heavier than ]STo. 13, German. Heavier will not do. It may be necessary to occasionally remove and straighten the lever a little, in order to maintain the pressure. Should one tooth be rotated sufficiently before the other, further move- ment may be arrested by removing the band and soldering a lug on the lingual surface, resting against the lateral inci- sor. When in position, they are retained by substituting a piece of the non-elastic gold Avire, " G," Fig. 17, for the spring Avire. The backAvard movement of teeth in the line of arch is accomplished by the appliance shoAvn in Fig. 29. The first molar is banded in the usual manner, and the tube of AND HAND-BOOK. 79 RETRACTION OF CUSPID. Fig. 29. the heavy traction screAv, shown at UA" Fig. 17, rigidly soldered to the band. The cuspid to be moved is banded, and one of the short tubes, shoAvn at UD" Fig. 17, is soldered to the band to receh^e the large traction screw, "A" Fig. 17. On turning the nut, traction is produced and the cuspid pulled or tipped into place. Fig. 20 shoAvs a side vieAv of the same. The screAv may be applied either upon the out or inside of the arch, and should the cuspid also require to be drawn into the line of arch, as Avell as backAvard, it may be accom- plished at the same time, by bending the screAv at the point Avhere it enters the long pipe. It will gradually draAv into the pipe as the tooth is moved back thereby accomplishing both movements. The easiest Avay to adjust this appliance is to first cement the band upon the cuspid tooth. After the cement has become thoroughly set, the angle of the traction screAv is hooked into the pipe, and the other band is now latched over the molar. The greatest care should be taken to make this attachment accurate, using the strongest cement. The nut should never be tightened enough at one time to strain the attachment. After the tooth is moved back, it is retained by the screw already in position, or that may be removed and a piece of the gold Avire be inserted in its place. The movement of a tooth forward in the line of arch is accomplished in the same Avay, only selecting teeth from the 80 STUDENT'S MANUAL opposite side to be used in overcoming the resistance of the teeth which are being moAred. The moATement of a tooth from Avithin, outAArard in the line of the arch, is shoAvn in Fig. 30, and is accom- Fig.30. plished by the jack-screAv ilJ," Fig. 17. A firm anchorage for the resistance of the screAA7 is obtained by banding and tubing the left cuspid and passing through the tube a piece of gold Avire, long enough to extend to and rest against the adjoining teeth. The opposite cuspid to be moA^ed is banded and a retaining tube, " R," Fig. 17, is soldered to the labial surface. The lingual surface has a slot cut in it to receive the flat end of the jack-sereav ; the other end of the tube, in which the screw plays, is so notched Avith a file that it rests securely against the re-inforcement Avire, and the tube against the lingual surface of the cuspid band. Movement is accomplished by tightening the nut, After being brought into position, the tooth is retained by passing a short piece of the gold wire through the retaining tube on the labial surface, as shown in Fig. 31, AA'hich is held in place until the tooth has become firmly set in its neAv position. RE-INFORCED ANCHORAGE. UM. - LFlG. 31. RETAINED AND HAND-BOOK. 81 OUTWARD. Fig. 32 shows a cuspid tooth being moved outward. The base of the FlG 32 jack-screw is sol- dered to a band en- circling the opposite cuspid, and re-inforced by a spur, resting against the first bi. cuspid, and also by the large traction screw which is hooked into a pipe, soldered to the labial surface of the band, and passing in front of the incisors through a tube, against which the nut works, soldered to a band on the labial surface of the lateral incisor. In this case, the left central and lateral were moved for- ward in the line of arch, thereby closing the space between the centrals, and, at the same time, providing space for the out-moving cuspid. The large screw was beaten flat and polished before insertion. Fig. 33 shows the same case after completion. Another Fig. 83. method of securing resistance for the base of the jack-screws, in accomplishing the outward movement, is shown in Fig. 34, where two central in- cisors are being forced out of in-lock, pipes were soldered to the palatine sides of bands, encircling the second bicuspids; the ends of a wire arch were slipped through these pipes, CASE AS COMPLETED. 82 STUDENT'S MANUAL and rested against the FlG- 34- molars. Two short pipes were soldered to the wire arch, oppo- site the teeth, to be moved in lines corre- sponding to the direc- tion of the movement. Two jack-screws were slipped into these pipes, the flat the arch as anchorage. ends of the same were inserted in slots formed in the lingual sides of the bands encircling the teeth to be moved. The screws in this case were only one-fourth of an inch in length. After the nuts on the screws had traveled the length of the threads, they were again screwed back, and the wire arch moved forward and keyed into position by delicate pins, passing through holes in the pipes on the anchor teeth, as shown in the engraving. (The pipes into which the jack- screws rest should have been represented as being soldered to the upper side of the wire arch, instead of the lower, as shown in the engraving.) Another method of re-inforcing the anchorage in moving a tooth outward is shown on the right in Fig. 35. The second bicuspid is made the principal anchor- age against which the base of the tube is soldered. The band encircling the lateral incisor has a slot cut in it to receive the end of the jack-screw. The anchorage is re-inforced by means of a wire loop which hooks into tubes upon the adjoin- ing central and cuspid, and Fig. 35. INCREASED ANCHORAGE. AND HAND-BOOK. 83 is looped OArer a spur upon the body of the jack-screAv tube. The central and cuspid cannot be pushed outward on account of this re-inforcement, and the three teeth constitute the anchorage instead of one. The several parts of this appliance are shoAvn at Fig. 36. Outward movement is accomplished by another simple Fig. 36. method, sIioavh on the left of Fig. 35, as folkrws: A strip of band material shoAvn at "F," Fig. 17, is looped about the malposed ,, ,, , , . , THE SEVERAL PARTS OF THE tooth, the ends resting upon the appliance. labial surfaces of the adjoining teeth. To one end of this strip is soldered a tube UC," Fig. 17,' placed vertically, Avhile to the other end a similar tube is attached horizontally. Into these tubes the small traction screAv " B," Fig. 17, is placed, being bent to conform to the shape of the arch, and being used in this case to push instead of to pull. The parts of this device are shoAvn separately at Fig. 37. Fig. 38 sIioavs the teeth retained after the Fig. 37. case AAras completed. Expansion of the arch is accomplished by banding and tubing the first and last teeth of those to be moved, on eaoh side, and connecting them by means of steel wire passing through the tubes. The jack-sereav is then placed in position across the arch from Avire to Avire. Collars or short tubes are soldered to the Avires at intervals to keep the screAv in proper position. These collars must be attached by soft solder, that the temper of the steel Avire may not be disturbed. The jack-screw may be moved fonvard or backAvard accord- in to the Ararying requirements of the case. DEVICE FOR OUT- WARD MOVE- MENT. RETAINED. 84 STUDENT S MANUAL Before placing in position the Avires Avhich pass along the sides of the arch they should be bent to correspond to the shape of the sides of an ideal arch, or exactly as Ave wish the teeth to be arranged after the desired position is gained. The appliances in position are accurately shoAvn in Fig. 39, Avith the exception that the tubes attached to the posterior bands should be nearly perpen- dicular instead of hori- zontal. The movement from Avithout, inward into the line of the arch, may be accomplished,as shoAvn in Fig. 40. The cuspid tooth is banded and a piece of the gold Avire bent sharply at right angles hooked into a pipe, soldered to the lingual surface. The other end of the Avire is soldered to a pipe through Avhich the small traction screw is slipped and against which the nut works. The other end of the traction screAv is hooked into a pipe soldered to a band encircling the first molar. The anchor- age of this tooth is further re-inforced by a piece of the gold Avire, Avhich is slipped through a tube sol- dered to the buccal surface of this band, EXPANSION. Fig. 40. 4 AND HAND-BOOK. 85 the end of the Avire resting against the adjoining teeth. Re- tention is accomplished in a manner similar to that shoAvn in Fig. 38. Another very nice method of gaining anchorage for the small traction screAv in draAving teeth inward into line of arch is illustrated in Fig. 34, using the Avire arch to pull to, instead of pushing from, as illustrated. In using the traction screAv in this way, it should be, of course, cut very short, so that the movements of the tongue may be interfered Avith as little as possible; and if the tongue be abraded by the end of the screw as it emerges from the nut, a very nice Avay of protecting the tongue, as in all similar cases, is for the patient to lay over the end of the screAv a small piece of the very common article known as cheAving gum. With the above appliances, any form of irregularities may be treated. There is one form, hoAvever, characterized by excessive prominence of all the superior teeth, and illus- trated by Fig. 41, in Avhich the force required for mov- ing backAvard all of these prominent teeth is usually too great to be borne by the posterior teeth as anchorage ; and, owing to this insuffi- ciency of anchorage, the usual result is excessive protrusion. that the molar teeth are frequently tipped fonvard, and faulty occlusion estab- lished, without accomplishing the desired result. On this account I have devised an appliance to be used in these special cases, the anchorage of Avhich will be transferred to the back of the head by means of the occipital bandage. It is known as Appliance Xo. 2, and shown in part in Fig. 42. It is 86 STUDENT' MANUAL PART OF ANGLE'S APPLIANCE NO. 2. Fig. 42. made and applied as follows: The first molars are carefully and accurately band- ed. Pipes, ^ of an inch in length, arc soldered on the buc- cal surface of the bands, on a line par- allel Avith the gum. A Avire of hard- draAvn, platinized gold, about Xo. 19 gauge, and long enough to encircle the dental arch, and carefully bent to conform to the shape of the same,provided the dental arch to be correct in form; but if it be contracted and the teeth occupy irregular positions, no attention is paid to the form of the existing arch, but an ideal arch is formed for the case ; or, in other Avords, the Avire arch is bent to exactly the form to which Ave Avish the teeth to be arranged Avhen the operation is completed. The ends of the ideal arch are iioav slipped through the pipes on the molars. The anterior part of the arch is kept from slid- ing up and im- pinging upon the gums by resting in suit- a b 1 e notches formed in the delicate bands encircling and cemented to the central or lateral incisors. It is shoAvn in posi- tion upon the teeth in Fig. 43. APPLIANCE NO. 2 IN P03ITIOK. Fig. 43. AND HAND-BOOK. 87 Fig. 44 represents a traction bar used for conveving the Fig. 44. TRACTION BAR. force from the occipital bandage and distributing it to the wire arch. A spur or standard Avill be seen in the center of this bar, provided Avith a socket in the end, Avhich, when in position, engages a small ball soldered to a delicate tube encircling the center of the Avire arch, as is shoAvn in Fig. 40- If the reader is familiar Avith the appliance so far described, it Avill be seen that the force received from the occipital band- age is distributed to the Avire arch through the ball and socket joint. The ends of the traction bar may, therefore, be moved in any direction Avithout interfering Avith the pres- sure from the bandage. The advantage of this attachment is that, in consequence of the freedom of motion, an}- jar or shock upon the traction bar Avill not be transmitted to the tender teeth. As the bandage and bar are to be avoiti only at night, shocks from contact Avith the pilloAv Avould be Arery liable to occur and occasion much pain, Avere it not that the bar is proATided Avith this freedom of movement. This is a point of advantage Avhich I think all Avill appreciate, and one possessed by no other device AvitliAvhich I am famil- iar. The usual method is to attach the traction bar, or its equivalent, to a SAvedged or A-ulcanite cap covering, and firmly resting against all the teeth to be moved. As the heavy rubber ligatures of the bandage act during the night onfv, proArision must be made to hold through the day Avhat is gained at night. This is accomplished hv the spring-dogs attached to the pipes, fastened to the bands en- •circling the anchor teeth, catching into the delicate notches in the wire arch, as they pass through the pipes, as shown in Fig. 43. This effectually prevents the loosened teeth from 88 student's manual springing back and interfering Avith the healing process- Another advantage of the device is, that not only the prominence of the teeth is reduced, but teeth that are irregular are gradually forced to take regular positions and conform to the shape of the ideal arch; something impos- sible with devices having fixed caps of vulcanite or gold. Still another advantage is, that if the arch needs expanding,, as is frequently the case, it may easily be accomplished at the same time the teeth are being moved backward, by lac- ing to the Avire arch such teeth as need to be moved outward. For the bandage proper, I greatly prefer the common silk traveling cap, shown in the engraving, or the knit jersey cap, to the contrivances usually used for this purpose, as these fit the head snugly and distribute the force exerted by the strong ligatures over more surface, and are, consequently more easily Avorn. Tavo ligatures should be attached to the cap, on each side, one above the ear, and one below the earr as shoAvn in Fig. 45. If FlG 4,5 the bands be of equal Avidth, the force Avill be exerted in the direction of the meatus of the ear. This is the point to Avhich, in most cases, the force should be directed. In some cases, hoAvever, the teeth should be compressed in their sockets as Avell as draAvn backAvard. This is easily accomplished by dis- pensing with the ligature beloAV the ear, using the upper only, but of double strength, attaching it at a point on the cap as far for- occipital anchorage. ward as desired. AND HAND-BOOK. 89 After the teeth have been moved into the desired posi- tion, they are effectually retained by the Avire arch, and the head gear and traction bar are, of course, dispensed Avith. Extra care as to cleansing the teeth should be observed by the patient Avhile Avearing this, as well as all other appliances. The traction bar and bandage may also be used to great advantage in the movement of single teeth, or in assisting other appliances, as for example a single prominent incisor? encircled by a band, on the labial surface of Avhich has been soldered a ball Avhich engages the socket in the spur of the traction bar. Or a cuspid may be moved backAvard in the same manner; but in this case, the spur should be moATed from the center toAvards the end of the traction bar, and the ligatures attached to the long end of the bar should be of less strength. The bandage and bar may be used to assist the appli- ances shoAvn in Figs. 27 and 28, in double rotation. Should these teeth begin to shoAV undue prominence as they rotate, by reason of pressure from the adjoining teeth, the bar and bandage, applied for a feAv nights, Avill effectually remedy this annoyance. It may also be used to advantage, in the same manner, in assisting the lever in single rotation. Other appliances of this bandage and bar might be given, but they Avill suggest themselves to any one in Avhose hands the appliances may be. CHAPTER XXIII. FRACTURES OF MAXILLARY BONES. IX the treatment of fractures of the jaAvs the all-impor- tant principle, after securing perfect apposition of the parts, is that they shall have rest—absolute, uninterrupted rest. But, owing to the A^ast number of movements to which the inferior maxilla is susceptible in health, and the many causes tending to produce these movements, it becomes ex- tremely difficult to secure the requisite amount.of rest to enable nature to effect the needed repair. Dr. Xorman Kingsley has Avell said, " Of all the frac- tures the surgeon is called upon to treat, there is more diffi- culty in the management of those of the inferior maxilla than those of any other bone." And Dr. Charles G-. Brown makes a statement in the Medical Record of October 6,1889, which it is Avell to remember while considering this subject. He says: " In the treatment of fractures of the inferior maxilla, as in fractures of all other bones, our success is in direct ratio to our recognition and antagonization of the physiological contraction of muscles, restoring the lost bal- ance of action, and thereby securing rest in proper position." Xow in order to soh-e the problem of securing rest, almost innumerable devices are used. Some of these are extremely complicated, difficult to make and to apply, and many of them extremely cumbersome and annoying to the patient, and, OAving to the faulty principles on Avhich they are constructed, accuracy and certainty of correct results are only probable, and Avith many of the ap- pliances, impossible. In treatment of fractures of the maxillary bones, I shall divide the subject into three classes. 90 AND HAND-BOOK. 91 The first class comprises all cases of simple fracture in Avhich the teeth are good, especially on each side of the region of the fracture. They should be sufficiently sound and firm in their attachments to afford good anchorage for the appliance which supports the fracture. The second class comprises all fractures where the teeth are unsuited, from any cause, for anchorage, but sufficient to give a correct articulation of the jaAvs Avhen they are in proper occlusion. The third class comprises all fractures of jaAvs which are edentulous. the device used in the treat- ment of fractures of the I first class, and a description of the case as treated by myself will be sufficient to convey an idea of the line of treatment. May 29, 1889, Xels Pe- terson, aged tAventy-one, was admitted to St. Anthony Hospital, of this city. He had fallen from a lumber pile fifteen or tAventy feet to the ground, and, besides receiving severe bruises, had sustained a simple fracture through sym- physis, terminating however, in front, betAveen the central and lateral, on the left side, as shoAvn by the line in the en- graving. The fractured bone, Avhen first seen, Avas quite Avidely separated at the top, and the left central incisor much loosened. He Avas treated as folloAATs: The ends of the fractured bones Avere carefully placed in their proper positions and temporarily fastened by lacing the teeth together with silk ligatures. The cuspid teeth, being very firm, Avere carefully banded in the manner already described on page 75. Pipes were soldered to these bands horizontally. The large traction REDUCING FRACTURE WITH ANCHOR SPLINT, 92 student's manual screAv shoAvn at " A," Fig. 17, Avas iioav slipped through the pipes, and the bands firmly cemented in position upon the teeth. The nut Avas then turned upon the screw until the fractured ends of the bones Avere drawn snugly together. This appliance Avas avoiti without displacement or further trouble for tAventy-one days, Avhen it was removed, the bones having become firmly united. I may add that, during the time the appliance Avas AArorn, so firmly Avas the jaAV supported that the patient suffered but little inconven- ience, and after the third day partook regularly of his meals, using his jaAV freely, but, of course, aAToiding the hardest food. After removing the appliance, a careful impression of the jaw was taken, a model made, and the appliance placed upon it, from which the engraving here figured Avas made. The loAver part of the jaAV is, of course, diagramatic, as added by my engraATer. It should be borne in mind that the principle on Avhich this appliance is based is not the same as Avhen the teeth are simply Avired together, but very different, for, in Aviring, the upper part of the fracture only is tipped or drawn together, while no pressure or support is given to the loAArer part. While in the principle here shoAvn it Avill be seen that because the bands and pipes are rigidly attached to the an- chor-teeth tipping is impossible, and pressure is exerted equally on the loAver and the upper part of the fractured end of the bones, since they are drawn together by the screw. This is another illustration of the correct anchorage described on page 74, or, as a friend remarks: " It is a Malgaigne splint, if you please, except that the hooks are not foreign bodies." This device may be applied in any locality in either jaAV, provided suitable teeth for anchorage be not too remote from line of fracture. The screAv may be bent to accommodate the curve in the jaAV, should the fracture occur in the region of the cuspids. AND hand-book. 93 The treatment for cases of the second division may be understood from the folloAving case, also treated by myself, and illustrated in Fig. 47. fracture on the right side, beginning Avith the socket of the second bicuspid, extending down and backward, and involv- ing the socket of the first molar. The second bicuspid had fallen out, and the first molar Avas much loosened. The sec- ond molar had been lost years before, Avhile the third molar, as Avell as all the remaining teeth, were much abraded and loosened by salivary calculus. The second fracture Avas situated on the opposite side, high up in the ramus of the jaAV. I could not detect the exact course the line of the fracture had taken, but the grinding of the ends of the bones and the great pain occa- sioned by the same Avere unmistakable evidences of a frac- ture. The patient, as is usual in all such cases, Avas unable to close his jaws. The fracture on the right side Avas Avidely separated, and the anterior piece much depressed by reason of the action of the digastric muscle. The posterior piece of bone being drawn firmly up and the molar teeth occluding by reason of the contraction of the masseter muscle, he Avas treated as folknvs: Bands Avere made to carefully encircle all four of the 94 student's manual cuspid teeth (they being most firmly attached in their sock- ets). The fractured ends of the bones Avere placed in careful apposition, and the loAver jaAV closed carefully, antagonizing the loAver teeth Avith the upper, using considerable force, hoAvever, and occasioning so much pain that anaesthetizing the patient became necessary. The points on the bands, Avhere the little pipes shoAvn in the engraving should be attached, Avere carefully noted and marked. The bands Avere slipped off, and the pipe soldered to the same. The bands Avere then cemented in their proper position upon the teeth, and tAvo small traction screAvs, shoAvn in the engraving, and also at " B," Fig. 17, inserted in the little pipes. The jaAvs were closed and the nuts turned on the screAvs until the jaAvs Avere draAvn firmly together, and each tooth occupied its exact position. During an attack of coughing in the night folloAving, one of the bands Avas Avrenched loose, but AATas easily replaced, the next day. Xo further accidents or trouble occurred, the patient readily taking nourishment through the spaces be- tAveen the teeth. Thus the fractured jaAV was firmly sup- ported, Avithout the least motion, for tAventy-tAvo days, Avhen the appliance Avas removed, shoAving most excellent results. That the patient Avas a great lover of the clay-pipe is shown in the engraving, by the much-Avorn ends of the lateral incisors, which resulted from holding the stem of the pipe- While AATearing the appliance he Avas not debarred from his favorite comfort. He. was, hoAvever, compelled to grasp the stem betAveen the lips, instead of the teeth. • Case Xo. 3 possesses several points of special interest, although the fractures occurred in regions similar to the case just described; and the appliances, though involving similar mechanical principles, Avill be found to be greatly simplified. December 28th, Thomas Brennan was admitted to the Dental Infirmary of the University of Minnesota, suffering from the effects of a blow received on the left side of the jaAV from a cant-hook, Avhile Avorking in lumber camps of AND HAND-BOOK. 95 Wisconsin, which produced fracture of the jaAV in two places. The first fracture Avas on the left side, beginning betAveen the first and second bicuspids, and extending doAvnward and backward so far as to involve the lower part of the anterior root of the first molar. The second fracture was on the right side, directly through the angle of the jaw. The fractures had occurred thirty-two days previous to his ad- mission to the infirmary, during which time nothing had been done to reduce the fracture. He reported that he had called upon a physician, Avho supposed the trouble was merely an abscessed tooth, and had lanced the gum Avith the view of reducing the swelling. Later, the patient had called upon a dentist in one of the smaller towns, who also failed to diagnose the fracture, and extracted both bicuspids in the hope of giving relief. Upon examination, I found considerable swelling in the region of this fracture, with the usual result; the patient being unable to close his mouth by reason of the anterior piece ©f the fractured bone being drawn down by the con- traction of the depressor muscles. A false joint had also become established. The bone could be easily worked with- out causing pain. At the fracture of the right side, there was little or no displacement; the swelling was also slight. With the assistance of Prof. Leonard, the patient was anesthetized; the ends of the bones were then rubbed forcibly together, with a view of breaking up the false attachments and stimulating activity in repair. The ends of the bones were now placed in perfect appo- sition, and the jaw closed, taking great care to articulate the teeth in their correct position against the upper ones. The jaAV was now firmly bound in this position to the upper teeth, in the same manner as described in case Xo. 2, Fig. 48. only that method Avas improved upon A §P2T BTl by using clasp bands, as shown in i^HT^v Xo cement Avas necessary; and, angle's fracture bands. a 96 student's manual instead of the screws, small metallic buttons were soldered to the sides of the bands (as shown in the cut), around which were wrapped, in the form of the figure 8, fine binding wire, as shown in Fig. 49. Fig. 49. FRACTURE REDUCED. Four bands were used encircling the four cuspid teeth. Those bands shown upon the molar teeth in the engraving were not used, but are shown for the purpose of illustrating their use in such cases as might occur. At the end of seven- teen days, the bands were removed and the patient dis- charged, the bone having been firmly united. It might be urged, as an argument against this method, that the teeth being closed, and the jaws being firmly bound together, the patient would be unable to take sufficient nour- ishment. This, however, is untrue; for it rarely happens that a patient is found without some teeth missing, thereby leaving abundance of space for the passage of the liquid foods; and, even if all the teeth were sound and in perfect position, it has been proven there is plenty of space between the teeth, and behind the molars, and between the upper and lower incisors, for taking all nourishment necessary. Of course, in such rare cases, much more time would be necessary in taking nourishment. AND HAND-BOOK. 97 With suitable sized bands of this style almost any one could readily reduce in a few minutes a fracture belonging to this class, and in cases where crowding of the teeth ren- ders difficult the slipping of the band between the teeth, space may be made by forcing a thin spatula between the teeth for a few minutes. The third class, comprising fractures of edentulous jaws, is fortunately very rare. The method of treatment I propose is similar to that already described in the first class. The appli- ance to be used is based upon practically the same principle; only in place of the teeth small bone hooks are used, drilling for their reception a suitable cavity on each side of the fracture, comparing in position to the original sockets of the teeth, the same as implanting were intended, only the cavities thus made need not be nearly so large or deep. They should also be drilled obliquely, to correspond to the course taken by the bony hooks. The hooks, before insertion, should, of course, be made antiseptic. In conclusion, I may add that the extreme simplicity and great efficiency of this system of treating fractures, to- gether with cleanliness and comfort to the patient will, I believe, be appreciated by all who are interested in this branch of dental surgery. EDWARD H. AXGLE, D. D. S., 13, 14, 15 Syndicate Block, February 5, 1890. Minneapolis, Minn. 32gQ • -vn* uoijoas vnan ap™o s«ivHaMaoS^oaoHiis 5>'- V ■t; --..->