MICROSCOPIC EXAMINATION OF A CASE OF CARIES OF A 
MONKEY’S TOOTH. 
W. D. MILLER, M.D., D.D.S., BERLIN. 
(Reprinted from the Dkntal Cosmos for November, 1892.) 
It is well known that the Quadrumana are not exempt from decay 
of the teeth. Particularly in captivity they are by no means infre- 
quently subject to this disease. I doubt, however, if many are aware 
of the terrible havoc sometimes wrought upon the teeth of these ani- 
mals by decay ; nor has, to my knowledge, a microscopic examina- 
tion of the decayed tissue ever been made. 
It is not difficult to find traces of caries in every collection of apes’ 
or monkeys’ skulls, but some of the most pronounced cases I have 
ever seen are in the possession of Dr. Barrett, of Buffalo,—among 
others, the skull of a monkey from the London Zoological Garden, 
in which every single tooth with the exception of the lower incisors is 
decayed. The right superior central incisor is decayed to the pulp, 
and one-third its length broken off; the left superior incisor is a com- 
plete ruin, and shows evidences of alveolar abscess. Other skulls 
show ravages quite comparable to the worst cases of decay seen in 
human dentures, complicated with diseases of the alveolar process, 
abscess, necrosis, antral troubles, etc. 
I have in my possession the skull of a monkey, which was pre- 
sented to me by a former pupil, Zahnarzt Sietas. The twenty-seven 
teeth now present show fourteen cavities of decay. Particularly the 
masticating and buccal surfaces of the molars are attacked ; also the 
approximal surfaces of the incisors, the lower centrals being decayed 
on both approximal surfaces. I obtained material for microscopic 
examination from one of the molars by placing it for twenty-four 
hours in water to soften up the dry tissue. I was then able to scoop 
out a piece of the decayed dentine with a spoon-shaped excavator. 
This was at once cut on the freezing microtome, and stained by the Gunther modification of the Gramm method. A section under a 
power of about 500 diameters is reproduced in the accompanying 
figure. 
It will be seen that the same appearances repeat themselves here 
that have been found in human teeth, both living and dead, in caries 
of horses’ and dogs’ teeth, etc. In the deeper parts we find the 
Carious Dentine from a Monkey’s Tooth. Circa 500: 1. 
tubules crowded with bacteria and much distended ; nearer the sur- 
face the basis-substance is broken down, the tubules melted together, 
and the whole mass of the tissue in a state of dissolution. In the 
case before us the destruction has been effected chiefly by micrococci; 
only at isolated points a few bacilli may be found by careful exami- 
nation under the microscope.