VETERINARY DENTAL SURGERT. 11 



Posterior, it is thin and completes the interdental 

 space. (In the Ruminantia the pre-maxilla is broad, 

 its inferior surface flat and destitute of alveolar cav- 

 ities, hence it possesses no incisor teeth but instead i s 

 covered by a dense cartilaginous pad, against which 

 the lower teeth press the food while the animal is 

 grazing). The processes are external and internal. 

 The external is the largest and longest, its outer sur- 

 face convex and smooth, its inner surface being 

 covered by the mucous membrane of the nose. The 

 internal process is flattened and thin, the superior 

 surface forming part of the floor of the nasal fossa. 

 The inferior surface forms part of the hard palate. 



The inferior maxilla (Fig. 1-25) is a large V- 

 shaped bone situated below the upper jaw and with 

 which it articulates. It consists of two symmetrical 

 branches which are flattened on both sides, wider 

 posteriorly than anteriorly, curved upward at the 

 upper third and joined anteriorly so as to leave a 

 space, which is known as the intermaxillary space. 

 The external surface is smooth anteriorly and rough 

 posteriorly. The internal surface is smooth and flat 

 anteriorly, and rough and concave posteriorly. It 

 presents a large opening, the inferior dental foramen, 

 which passes through the bone below the roots of 

 the molar teeth. The superior or alveolar border is 

 straight anteriorly and concave posteriorly. The 

 first contains six alveoli for the lower molars. The 



