THE MOUTH, ORAL OR BUCCAL CAVITY 253 



all, and its place is afterward taken by the second 

 permanent bicuspid. 



Of the permanent teeth the incisors are the 8 central 

 cutting teeth, 4 each above and below, the former 

 being the larger. They are bevelled at the expense 

 of the posterior surface. The canines (cuspidati) are 

 2 in each jaw, being situated 1 behind each lateral 

 incisor, the upper and larger being called the eye 

 teeth. The bicuspids (premolars or false molars), 



4 in each jaw, lie 2 each behind the canines, the upper 

 being the larger. The molars (true molars or multi- 

 cuspidati) are the largest teeth, and number 6 in 

 each jaw, 3 each behind the posterior bicuspids above 

 and below. They present 4 tubercles on the upper, 



5 on the lower crowns, and the root is subdivided into 

 from 2 to 5 fangs. The first molar is the largest and 

 broadest, the second smaller, and the third (wisdom 

 tooth) the smallest. 



Fio. 95 



Pulp Cavity. . 



Root. 



Vertical section of molar tooth. 



A vertical section of a tooth shows it to be hollow, 

 the cavity being continuous with the aperture in the 

 fang and filled up with the soft dental pulp, and is 

 hence called the pulp cavity. The pulp is sensitive, 

 highly vascular, and consists of connective tissue, 

 with cells, vessels, and nerves. The hard substance 

 of each tooth consists of three parts: the iwry or 

 dentin, the enamel, and the crusta petrosa or cement. 



