ANIMAL DENTISTRY. 19 



ring to it as the "right-first-superior molar," the "left- 

 fourth-superior molar," the "left-inferior-lateral," or the 

 "left-inferior canine," etc., throughout the dental arcades. 



DIVISIONS OF A TOOTH. 



Anatomically a tooth is divided into the crown, neck, 

 fang, roots, table, infundibulum and cup. The crown refers to 

 the projecting portion, or in other words that part of a nor- 

 mal tooth that is visible. The neck is the part covered with 

 gums, or the part between the crown and alveolar margin. 

 The fang is the imbedded portion or the part between the al- 

 veolar margin and the projecting roots. The roots are the 

 small projections at the imbedded extremity of the fang. 

 The table refers to the grinding or contact surface. The 

 infundibulum is the cavity on the table produced by the in- 

 folding of the enamel, while the cup refers to the unfilled 

 portion of the infundibula of the incisors. 



The surfaces of the teeth are frequently referred to as the 

 "buccal surface," the "labial surface," or the "lingual sur- 

 face." In the case of the molars the buccal surface is the 

 external and the lingual, the internal, while in the incisors the 

 lingual refers to the posterior surface, and the labial to the 

 anterior. 



Other names frequently used in the study of dentistry are 

 "alveolar margin," referring to the outer border of the alveo- 

 lar cavity; the "gingival margin," which refers to the outer 

 border of the gums, and "contact margin," which implies 

 the cutting border of a tooth such as an incisor of carnivora. 



STRUCTURES OF THE TEETH. 



A tooth is composed of hard and soft tissues, of which 

 the former predominates in volume and importance. The 

 hard tissues comprise a body of dentine, capped with enamel, 



