1EMTAL WMim 000OO00 IM©S§EW DENTAL DRAWING DENTAL DRAWING BY EDWARD DROSEN, D.D.S. in HEAD, DEPARTMENT OF DENTAL DRAWING, MARQUETTE UNIVERSITY COLLEGE OF DENTISTRY WITH ILLUSTRATIONS AND TWENTY-TWO FULL PAGE PLATES FROM ORIGINAL DRAWINGS BY THE AUTHOR BROOKLYN, NEW YORK DENTAL ITEMS OF INTEREST PUBLISHING CO LONDON CLAUDIUS ASH, SONS & CO. 1924 Copyright, 1924, BY DENTAL ITEMS OF INTEREST PUBLISHING CO. Printed in the United States of America by J, J. LITTLE AND IVES COMPANY, NEW YORK FOREWORD The object of this text is not to produce artists but to develop the student’s or practitioner’s ability for drawing, and by drawing tooth form to teach dental anatomy. In the very earliest lessons to the youngest children, the alphabet is taught by writing the letters on Lhe blackboard. This is the commencement of the study of free-hand drawing. As they learn to write the letters of the alphabet, they unconsciously draw them, for writing is, in fact, only drawing from memory. Drawing is the language of form, having but two letters in its alphabet, the straight line and the curved line. In this respect, our pictures will be like our own written words, made up of combinations of straight and curved lines, with this difference, that, while the word may suggest a name or a thought, the drawing suggests the thing itself. Both drawing and writing depend, for attainment, upon the faculty of imitation; though drawing, being simpler in its elements than writing, is more easily acquired. From this we can conclude that every person who has been taught to write may, therefore, be taught to draw. Edward Drosen, D.D.S. June, 1924 Milwaukee, Wise. CONTENTS CHAPTER I PAGE The Benefits Derived from a Course in Dental Drawing 1 CHAPTER II How Art Is Associated with Dental Procedure 4 CHAPTER III Drawing Instruments and Their Use 7 The Drawing Board 7 T Square 8 Drawing Paper 8 Fastening the Drawing Paper 8 Drawing Pencils 9 Triangles 10 Compasses 11 Drawing Ink and Ruling Pen* 12 Scales 16 Drawing Pen and Holder 17 CHAPTER IV Cleaning Drawings 18 CHAPTER V Preliminary Directions 20 The Drawing Paper 20 Pencil Sketch 20 Inking 20 • CHAPTER VI Lettering 22 Spacing of Letters 22 Unaccented Slanting Letters 23 vii viii CONTENTS PAGE Unaccented Vertical Letters 26 Accented Slanting Letters 26 Accented Vertical Letters 26 CHAPTER VII Shading 30 CHAPTER VIII Shadows 34 CHAPTER IX The Teeth 36 Tooth Surfaces 37 Upper Central Incisor 38 Lower Central Incisor 40 Upper Lateral Incisor 42 Lower Lateral Incisor 44 Upper Cuspid 47 Lower Cuspid 48 Upper First Bicuspid 50 Lower First Bicuspid 53 Upper Second Bicuspid 54 Lower Second Bicuspid 56 Upper First Molar 58 Lower First Molar 60 Upper Second Molar 62 Lower Second Molar 65 Upper Third Molar 69 Lower Third Molar 69 Buccal Surfaces of Permanent Teeth 71 Lingual Surfaces of Permanent Teetli 71 Occlusal Surfaces of Permanent Teeth 71 Deciduous Teeth 71 Lower First Molar and Alveolus 74 The Mandible—Lower Jaw Bone 74- Occlusion of Permanent Teeth 78 CONTENTS ix CHAPTER X The Evolution of the Face 79 LIST OE PLATES 1. Unaccented Slanting Letters 25 2. Unaccented Vertical Letters 27 3a. Accented Vertical Letters 29 3b. Accented Slanting Letters 29 4. Shading 31 5. Upper and Lower Central Incisors 39 6. Upper and Lower Lateral Incisors 43 7. Upper and Lower Cuspid 46 8. Upper and Lower First Bicuspid 51 9. Upper and Lower Second Bicuspid 55 10. Upper and Lower First Molar 59 11. Upper and Lower Second Molar 63 12. Upper and Lower Permanent Teeth—Buccal View 66 13. Upper and Lower Permanent Teeth—Lingual View 67 14. * Bicuspids and Molars—Occlusal View 68 15. Upper and Lower Deciduous Teeth 70 16. Lower First Molar and Alveolus 73 17. The Mandible 75 18. Occlusion of the Teeth—Side View 76 19. Occlusion of the Teeth—Front View 77 20. Evolution of the Face—Infancy 80 21. Evolution of the Face—Maturity 81 22. Evolution of the Face—Senility 82 DENTAL DRAWING I THE BENEFITS DERIVED FROM A COURSE IN DENTAL DRAWING Dental drawing is the art of representing the form, size, and arrange- ment of teeth and parts associated with the teeth on a plane surface, as on a sheet of paper. In the course which this book outlines, the drawing of the teeth will prove of great assistance to you in determining the location of cusps, planes, ridges, grooves and surfaces of the teeth. The importance of root canal work is realized, and among the areas which you will he required to draw are the pulp cavities of all the teeth. This will familiarize you with the relationship of the pulp chamber to the dentine. By drawing the teeth, you will gain knowledge as to their various forms and sizes, as well as instruction as to the number of roots which the teeth have. The plate, representing the occlusion of the teeth, shows you their anatomical arrangement and their relationship to one another, as far as their inclined planes are concerned. It is also our object in this course, to study facial form and facial dimen- sion, as well as harmony and symmetry of the mouth and face. In drawing the plates which deal with the evolution of the face, you will note the change of facial form that has taken place from infancy to senility. Note the falling inwards of both lips in old age; the loss of expression in the margins; the 1 2 DENTAL DRAWING formation of heavy lines at Lhe corners of the month, and the general loss of vigor. A study of these things will be of benefit to you in your prosthetic work. This treatise offers you a practical course in lettering, which you can adopt for general use and for other classwork in your curriculum where lettering is required. A study of shading is included. Shading is necessary to make the object stand out and to represent different surfaces and textures. Dental drawing will increase your powers of observation and stimulate a taste for art and an appreciation of the beautiful. One does not need to he horn an artist in order to make use of this teaching. Every product of constructive dentistry, operative or prosthetic, will give greater satisfaction to your patient and to yourself if fashioned in lines of beauty and harmony, in addition to utility. It is also of decided advantage, if to good taste, there be added such skill with brush and pencil, that the desired effect can be pictured to the patient in advance of production. Dental invention is greatly aided by skill in freehand drawing. The order of procedure is this:—First, the idea, then the freehand drawing; next the working drawing; next the pattern in wood and finally the completed article. . v • Dental drawing trains the hand to obey the mind. One cannot draw what one cannot conceive. Dental drawing makes the observation and memory much keener. It is easier to remember what we draw, because drawing impresses the facts upon the mind. Dentists become workers with their hands; hence dental drawing, which gives a knowledge of design, proportion and construction, is hand work and should be understood. It may also be stated, that most dental instruments are handled in the same manner as a pen or pencil, the pen grasp. This similarity brings to light another benefit, that of developing precision and accuracy in the use of dental instruments. Dental drawing will give you skill of hand in expressing ideas and concepts in visible form, so that others may see and comprehend. It will prove more effective DENTAL DRAWING o O than the most elaborate print. Upon the completion of your course in dentistry, you will no doubt he called upon to give clinics and demonstra- tions in some field of dentistry, in which you may elect to specialize. As a clinician you will then realize the interest you can create during the evolu- tion of your sketch. This interest has a high educational value, for the drawing and its associated facts are impressed upon the minds of the audience. How frequently will a few rapid lines aid in a description. In fact, the man who has become a master of drawing will find that, almost unconsciously, he uses his ability to draw to assist him in his oral descriptions. II HOW ART IS ASSOCIATED WITH DENTAL PROCEDURE The skill of an able dentist is a matter of artistry and craftsmanship. This artistic skill, as applied to dentistry, is in a great measure constructive or restorative. The dentist first conceives the construction or restoration mentally, in the idea, and then executes it by practical, artistic skill so as to duplicate Nature to the closest possible degree compatible with the individual environment and requirements. This is well illustrated in the construction of the full denture. The teeth are placed in the proper position so as to harmonize with facial and arch form. They are neither too light nor too dark, but graduate in color, as in a landscape. In a landscape, the artist portrays the colors of the foreground, darker and deeper than those in the distance. The darker colors of the foreground, diminish in tone in the distance and sky. In the teeth, the deep colors are found in the necks of the lower anterior incisors. The incisal halves of the upper central incisors are the lightest, and the tone becomes darker as it shades away into the lateral incisors and cuspids. This produces a spot of high light in an artistic manner. The dentist shows his artistic ability by considering the color value of teeth, and by arranging the teeth slightly irregularly, and, if possible, so as to assume the positions formerly occupied by the patient’s natural teeth. We are confronted by similar problems in crown and bridgework. An artistic anterior bridge is one so constructed that very little metal shows. The pontics harmonize with the facial contour and complexion of the patient. Arch form must also be considered in the construction of an artistic bridge. 4 DENTAL DRAWING 5 The porcelain jacket crown stands preeminently a restoration indicating the highest standards of artistic skill in dentistry. In many instances a transfor- mation is effected, so surprisingly beautiful, that Nature is almost challenged. This crown can be used to correct such irregularities as protrusion, rotation, lingual malrelation, as well as every known tooth deformity. In a jacket 0 crown, art relates to the reproduction of individual characteristics in form and color of the natural tooth. Art has also progressed in operative dentistry. The gold inlay, ana- tomically carved and highly polished, is replacing the old, discolored amalgam filling. The result, while not perfect, is more pleasing and has a higher esthetic value than amalgam. The modern root canal technician exercises great care in his work, so as not to discolor the tooth, and if the tooth be discolored, steps are taken to decolorize the dentine to its natural shade. The highest form of art, however, is wrought by the hands of the skilful orthodontist and oral surgeon. The unfortunate child, with irregular teeth and malformed face, which may be even repulsive, is at times transformed into an attractive or even beautiful being. I cannot but recall at this time an interesting hare-lip case. The opera- tion was completed save for the suturing of the vermilion tissue which was to form the child’s future lips. At this stage of the operation, the oral sur- geon, with the soul of an artist, used one of the fair nurses as his model, so that the lips might be properly formed and so that this child might take its place on this earth with no such handicap. I was fortunate enough to see this case after a lapse of several years, and I would challenge the average layman to detect this congenital deformity. Such efforts to create and restore, can only originate with one who appreciates art and the beautiful; one possessing a knowledge of the laws of harmony and symmetry. Art is also associated with periodontia. Highly inflamed tissue, con- taminated with pus, is regenerated into healthy pink, firm tissue. Teeth 6 DENTAL DRAWING are cleaned and ground in corrected occlusion, so as to overcome elongation and irregularities, thus restoring them to artistic harmony with their approxi- mating neighbors. Such is the progress of art in dental procedures. Dentistry has progressed through the dentist’s application of art to dentistry. III DRAWING INSTRUMENTS AND THEIR USE The Drawing Board Tiie drawing hoard (Fig. 1) should he made of well seasoned straight- grained pine, the grain running lengthwise. To avoid the tendency of the Fig. 1. board to warp, the wood, of which it is made, is thoroughly dried before it is put together. But, as wood absorbs moisture from the air, warping will not he avoided if the hoard is kept near a stove, radiator, or other source of heat. The tendency to warp can he counteracted, to a considerable extent, by the manner of constructing the board. Most boards are either veneered, or hardwood cleats are screwed to the hack, to prevent the hoard from bending or warping. o o DENTAL DRAWING The drawing board should be so arranged that the artist can do his work conveniently and to the best advantage. T Square The T square is used for the drawing of horizontal lines. The short cross-piece of the T square (see Fig. 1) is called the head, and the long piece Fig. 2. is called the blade. The head of the T square should be firmly held against the left edge of the drawing board when drawing horizontal lines. You observe that it is quite a simple matter to draw horizontal lines accurately and easily by the use of the T square by drawing your lines along the edge of the blade and running the T square upward or downward. Drawing Paper The quality of drawing paper recommended for this series of lessons is smooth Strathmore, or Bristol hoard. These papers have a hard surface, and ink dries on them rapidly. Strathmore board has the advantage of with- standing erasures better than Bristol board. Either, however, will be found satisfactory. Fastening the Drawing Paper The paper is fastened on the drawing board by means of thumb tacks (Fig. 2) which are small tacks, having large, flat heads. When fastening a sheet of drawing paper on the drawing board, lay the paper on the drawing DENTAL DRAWING 9 hoard with the edges parallel to and equally distant from the sides. Insert a thumb tack in the upper right-hand corner, about l/\ inch from the edge of the paper, and press it in, until the head hears evenly on the paper all around. Line the upper edge of the paper so that it is parallel with the ruling edge of the T square blade. Then, by sliding the hand lightly and diagonally toward Fig. 3a. Fic. 3b. Fig. 4. the lower left-hand corner and holding the paper there, press in another thumb tack, as before. Lay the left hand on the middle of the sheet, slide it very lightly towards the upper left-hand corner, and insert another tack. The fourth tack is inserted in the same way as the third, except that the left hand is slid from the center to the lower right-hand corner. Drawing Pencils For drawing lines and laying off dimensions, a 4-H pencil, of any good make, should be employed. Do not use a pencil softer than this for this kind of work, as the point of a soft pencil wears away so fast that accurate work cannot be done. 10 DENTAL DRAWING This pencil should be sharpened as shown in Fig. 3A. Cut the wood away so as to leave about l/\ °f an inch °f lead projecting; then sharpen it flat by rubbing it against a fine hie or a piece of fine emery cloth or sandpaper that lias been fastened to a flat stick. Grind it to a sharp edge like a wedge (Fig. 3A), and round the corners very slightly, as shown in Figure 3B. Wooden Triangles Steel Triangles Fig. 5. For sketching in your layout a softer pencil is used. This pencil is sharpened to a point as shown in Fig 4. Triangles Triangles are used for drawing perpendicular lines, angles and parallel lines. The triangles most generally used are the 45 degree and 60 degree triangles, as shown in Fig. 5. DENTAL DRAWING 11 To draw a vertical line, place the T square in position to draw a hori- zontal line, and lay the triangle against it, so as to form a right angle. Hold both T square and triangle lightly with the left hand, so as to keep them from slipping, and draw the line with pen or pencil held in the right hand, and Fig. 6. against the edge of the triangle. Fig. 1 shows the triangles and T square in position. Compasses Compasses (Fig. 6) are used tor drawing circles and for dividing lines into specified lengths. They are fitted with two arms which may he adjusted to meet various radii. One of these arms is fitted with a steel point which acts as a center, when a circle is drawn. The other arm has a socket, into 12 DENTAL DRAWING which may he fitted several extensions. One extension is used when drawing circles in pencil; one for drawing circles in ink; and the other, the steel point, is used for dividing a line, or a given space into parts. The compasses when used with this steel point are called dividers. Have leads sharpened flat and Fig. 7. not to a point. Always sharpen the leads in this way, and insert them in the extension, so that the flat surface at the point of the lead will always face out- ward when a circle is being drawn. This insures a fine, clean line. Fig. 7 shows how the compass should be held for drawing circles. DENTAL DRAWING 13 Drawing Ink and Ruling Pen The ink recommended for drawing is waterproof, liquid, India ink (Fig- 8). A (pull is attached to the cork of every bottle of this ink, by means of which the pen may be filled. The quill is dipped into the ink and Fig. o. the end then passed between the blades of the drawing pen. No more ink than will fill the blades for a quarter of an inch, should he used; if too much is used, the ink is liable to drop and cause blots. The cork should be replaced in the bottle every time the pen is filled. Before the drawing ink is used, the bottle should be well shaken, because some of the ingredients of the ink settle to the bottom and, if the ink is not well mixed, the lines will appear gray. If the ink becomes too thick, it may be diluted by adding a solution composed of one ounce of water and four drops of aqua ammonia, until the ink is of the proper consistency again. Pure water alone, should not be used to dilute the ink. India ink that 14 DENTAL DRAWING has been frozen cannot he used, as the lines will be very gray and indistinct. IJie ink bottle should always be kept tightly corked when it is not in use. India ink dries quickly on a drawing, which is desirable; it also dries quickly on the blades of the pen, which is not desirable, because it prevents Fig. 9. Fig. 10. the ink from flowing freely, especially when the pen is adjusted for fine lines. The only remedy is to wipe between the blades frecpiently with a cloth. The blades should always he wiped out before the pen is laid down for any length of time. If the ink does not flow well, it may be started by moistening the end of the finger and touching it to the point, or by drawing 4 slip of paper between the points of the blades. The ruling pen is used for drawing lines of various widths. This ruling pen is fitted with two blades (Fig. 9). To fill the pen, dip the quill attached to the cork of your ink bottle and DENTAL DRAWING 15 insert between the blades of the ruling pen. No more ink should be placed in the pen than will extend from one-quarter to three-eights of an inch upward from ihe point of the ruling pen (Fig. 10). Visible outline light. Visible outline heavy. Jnvisjb/e _outline. Center line. Dimension line. r r -* Drown with correct position of pen as at A. Drown with correct position of pen but varying the__ pressure of pen against T-square .thus closing the nibs. Ragged line caused by slope of pen as at B so that both nibs are not in contact with the paper. er^a^^t^^an^^ contact of inked line with T-square blade. Also by failure to keep nibs dean. Fig. 11. Fig. 12. The edges of the T square, or triangle, are to he used only as a guide for a ruling pen. Both points of the blades of the pen must touch the paper. If they do not, your lines will be ragged (Fig. 11). Be sure that you hold 16 DENTAL DRAWING the pen perpendicular when using it (Fig. 12). Do not bear heavily on the pen, nor press it too hard against the edge of your rule, or guide. By regulat- ing the set screw, which holds the two blades of the ruling pen together, and then drawing lines along the edges of the T square, the width, or thickness of these lines may be regulated. Fig. 13. Fig. 14. Fig. 15. A little practice in drawing lines with this ruling pen will soon enable you to produce a great variety of effects, smoothly and easily. Scales Scales are used for laying off dimensions on drawings. The scales that are generally used, are triangular in shape, as shown in Fig. 13, or flat, with beveled edges. The edges of the triangular scale are graduated for different scales, but for our work the full-size scale is to be used. The full size scale is divided like the ordinary foot rule. DENTAL DRAWING 17 Drawing Pens and Holder For general purposes the best pens are probably Gillott’s No. 170 and No. 303. They are fairly flexible when broken in and are not too sharp. For lettering use the Gillott’s No. 303 pen. Gillott’s No. 170 pen (Fig. 14) can be used for shading and general work. Fig. 15 shows a satisfactory holder. IV CLEANING DRAWINGS A drawing is almost sure to become soiled from the rubbing of your sleeves and from dust. This may be prevented to some extent by covering the work, except the part on which work is being done, with paper thoroughly Fig. 16. Fig. 17. secured at the edges so as not to interfere with the operation of the triangles and T square. It is good practice, before commencing a drawing, to clean carefully the scales, triangles, and T square. The drawing board should be dusted before the drawing paper is tacked in place on it. An inked drawing should not be erased until the ink has thoroughly dried. 18 DENTAL DRAWING 19 All soiled spots and pencil lines can then he removed with an art-gum eraser (Fig. 16). This soft eraser will not injure the ink lines. In order to remove an inked-in line, or an ink blot, a hard eraser made of a mixture of rubber, Fig. 18. and emery or glass, should be used (Fig. 17). It is even sometimes neces- sary to use fine XX sandpaper to remove some ink blots. Do not use chemical ink eradicators, as they leave a yellow blotch on your paper. Fig. 18 shows a celluloid shield, with which it is possible to erase particular spots, without touching and thus injuring other parts of the drawing. V PRELIMINARY DIRECTIONS The Drawing Paper The size of the drawing paper to be used for the drawing work given in this course is 8j/2 x 11 inches Strathmore or Bristol board. Pencil Sketch The entire plate should first be penciled and the dimensions laid off accurately before any part is inked. Of course, the pencil work must not be so heavy that the ink will not take well to the surface of the paper. This pencil sketch, known as the “layout,” is first submitted to your instructor for his approval before it is finally inked. Full directions for laying out each plate are given later in the text. Inking When your pencil sketch has been approved, you may proceed to ink in the work. Allow yourself plenty of room when inking. Your arm should be free and unobstructed in its movements. Nobody can ink well in a cramped position. When inking, do not try to make speed at first; speed will come with practice. Draw slowly to begin with, taking care that each line is black and that the edges are clean. Be sure that your ink flows freely and does not clog the pen. When inking your horizontal lines, you will find it well to draw them along the edge of a ruler or a straight edge, tilting it so that the edge which is nearest the line is raised about l/\ of an inch above the paper. This 20 DENTAL DRAWING 21 method may also be used when inking your vertical lines, by running the head of your T square along the bottom of your board, taking care that the edge of the blade is raised so as not to catch up ink and blot your paper. Solid spaces will, of course, need to be first outlined in ink, then filled in. VI LETTERING Every student of dental drawing should have a thorough knowledge of lettering. You will learn how to make simple, clean lettering for practical purposes. The letters must be of uniform thickness and of the same style or “font,” as it is technically called. We will employ for our work the unac- cented letters, which are of two kinds, slanting and vertical; and the accented letters, slanting and vertical. Unaccented letters are adapted for drawings having many parts that are to be labeled, or on drawings where the space of lettering is limited, as the letters of this form can be condensed, without materially affecting their legibility. The slant style is the most natural, as the strokes approximate the direc- tion of the strokes in ordinary writing. Accented letters are generally used for main titles and subtitles. We will use the Gillott’s No. 303 pen for lettering (Fig. 14). It is possible to make more uniform lines with a pen after it has been used for a short time, than when it is new. Waterproof ink dries quickly and for this reason the point should be wiped frequently. A cloth free from lint, as the one enclosed with your waterproof India ink, should be used for this purpose, as the lint would get between the nibs of the pen and clog it. Spacing of Letters By spacing is meant the placing of letters at such distances apart as to give the appearance of equal spacing between all letters. The shapes of letters vary, some having slanting sides, some straight sides, and some rounding sides; others have projecting stems, so that only 22 DENTAL DRAWING 23 very general instructions can be given for spacing. Good judgment must he used for this. The letters of a word must be spaced so that the word will have an even appearance, and there will be no unduly large white space, or dark spot, at any point. More space is required between two letters, both of which have straight sides, than between two letters, one of which has a straight side and one a round side. Less space is required between two letters with rounding sides, as 00 or DO, than is required in either of the pre- ceding examples. The space at the bottom between the two capital letters, AL, should be small so that the space between them at the top will be reduced to the minimum. The capital letters, AW, have parallel sides, consequently, considerable space is required between them. The letters that cause the most trouble in spacing are A, W, V, X, and Y. Unless good judgment is used, their slanting sides pro- duce unequal white space. Letters with projecting strokes as F, J, L, and T, are difficult, at times, to combine with other letters. The letters that are most easily spaced are those with straight sides as H, B, N, D, etc. Unaccented Slanting Lettering This form of lettering is shown on Plate 1. The direction of the strokes is indicated by small arrows and the order in which they are made is shown by numerals. To produce well-formed and neat appearing letters, the direction and order of the strokes, as given, should be observed. Three elements enter into the construction of the form of letters. These are the straight line, the loop, and the hook, as shown on Plate 1, upper line; or modifications of the loop and hook, as will be seen by referring to Plate 1, second line. The loop is the main 24 DENTAL DRAWING element in the letters a, b, d, g, p, and q, and modifications of it enter into the construction of the letters c, e, and o. In the letters a, d, g, and q, the point of the loop is at the top, and in the letters b and p the point of the loop is reversed. The hook, with the turn at the top, is used in forming h, m, and n, and the reversed hook is used in u. The only difficulty that will be experienced in making the letters v, x, and y, both lower case and capitals, is to draw the sides of the letters at the proper angle. These letters will be well formed if the sides of v, and of the v part of the x and y, are drawn so that the upper extremities are equally distant from an assumed center line at the angle to which the letters are made, as shown on Plate 1, second line. Until the student becomes proficient in drawing the lines of letters at a uniform slant, a templet of the slant used in the illustrations may be used for drawing guide lines. It may be of either cardboard or wood. The angle, or slant, for the templet may be found by stepping off on a vertical line of any length, points to divide it into eight equal parts, and then stepping off three of these equal divisions on a horizontal line. A line drawn through the extremities of the vertical and hori- zontal lines will give the hypothenuse of a triangle of the correct angle or slant, and this angle may be laid off on a templet of any size. In practising the drawing of letters, care should be taken to have the slant and curved lines of all letters extended fully to the guide lines, and the letters should be of proportional width. If these instructions are not carefully followed, the letters will present an uneven appear- ance. Care should be taken to have the ascending stems of letters as b, d, f, etc., extend fully to the upper guide line; the descending stems of letters as f, g, j, etc., should extend the same distance below the base guide line that the ascending stems extend above the guide line for the height of the lower case letters. adcjq bfa ceo htnn xz vy /jf/t % t> 0 /?? x v; t~Y >y l %»i Z/-A L— 7Ai /^A // r' Jp J TT1 / bjS J ;A\ /Ak 1 f 7ii l 7 /2 / p / ?7 /"7-/ /-/-l 7 ./ y / / yA / \ 4 ); q / 4~* 1‘ / 7 Vy/ / A l / I f mokkmvm&m f ij H. /M 4? * i PLATE / fl. oEPurcmn/ 25 26 DENTAL DRAWING The rounded letters, as c, e, and o, are usually the most difficult to make, and close attention should be given to their construction. The loops and curves of letters should be practised until the hand becomes so accustomed to the movements that they can he made with ease and facility. Unaccented Vertical Lettering The unaccented, vertical letter, Plate 2, is a good form letter, but the beginner will find it harder to make the strokes uniform than in the ease of slanting letters, which are also more easily condensed. The formation of the vertical style of letters is shown on Plate 2, which also shows the order and direction of the strokes. The forms should be carefully studied and the order and direction of strokes followed. The rules given for the spacing of slanting letters will apply to the spacing of the vertical style. Accented Slanting Lettering This is the style of lettering shown on Plate 3B. It will be used for the main titles on subsequent drawing work. The slant of the letter- ing is 60 degrees and is made with a triangle. The rules given for spacing the unaccented letters apply to this alphabet. Care must be taken to have the letters the same thickness throughout. Accented Vertical Lettering Another type of lettering, shown on Plate 3A, is also used for large headings, or titles of the plates. The width of the spaces between the letters depends on the combination of the letters in words; the best plan to follow in this alphabet is to compare the spacing between the various letters as shown in the illustration. Note the space /\ l\ ~ D *1 *1 (( i . i :~~ v~p -v— ■ —"— i ii |i ii u i|\ /ii ih\ i ,L„ 2 ’ ] 1 3i i 1 y 2 i 1 l ’~|j |1 if \ H t— \/ I) 11 N /T 11 ~~ H c A *~ll lj T |i i y\ i i 1 1