130 



ANIMAL DENTISTRY. 



alveolar cavities for superior incisor teeth. It consists of a 

 body and two branches extending- 1>ack\vard. The upper 

 branch passes apward and backward along the superior 

 maxilla to the base of the nasal peak, where it enters into the 

 formation of the maxillo-nasal notch. The lower branch is 

 a thin plate loosely attached to its fellow and the superior 

 maxilla to complete the roof of the mouth anteriorly. 



The tongue of animals is a very strong, motile, musculo- 

 membranous organ, having a fixed attachment to the spur 

 process of the hyoid bone posteriorly, and a free extremity 

 anteriorly. It is held to the floor of the mouth by its mucous 

 membrane. Its upper surface is thickly paved with epi- 

 thelium. It is a tactile, gustatory, prehensile and masticating 

 organ. In mastication it serves the useful purpose of keep- 

 ing the food between the molars while grinding-, and to assist 

 in its backward passage when mastication is complete. 



The hard palate is a dense fibrous cushion covering the 

 entire roof of the mouth from the incisor teeth to the soft 

 palate. It presents a number of transverse bars which meet 

 in a longitudinal raphe. It serves the purpose of preventing 

 food from slipping freely outward, and to assist the tongue in 

 passing food backward. 



The cheeks arc composed of the buccinator muscle cov- 

 ered externally with the skin and internally with the buccal 

 mucous membrane. It is a loose curtain attached just be- 

 yond the alveolar border of each molar arcade. In masti- 

 cation it serves to keep the food between the teeth and to 

 complete the lateral boundaries of the mouth. 



The masseter muscle is a thick, wide and short muscle 

 located on the lateral aspect of the lower jaw. Its fixed at- 

 tachment is the maxillary spine and zygoma and its movable 

 insertion the external face of the lower jaw. Its function is 

 that of closing the jaws and drawing the inferior maxillary 

 slightly forward. 



