12 VETERINARY DENTAL SURGERT. 



second, which is thinner, is somewhat roughened for 

 muscular attachment. The inferior border is divided 

 into two portions, straight and curved, the latter 

 being convex and thick, the first rectilinear, thick and 

 rounded in the young animal, but becoming sharp 

 with age. The union of the two forms the angle of 

 the jaw. The posterior extremity presents two 

 eminences, a coronoid process anteriorly and a con- 

 dyle posteriorly. These eminences are separated by 

 a deep notch, the sigmoidor corono-condyloid notch. 

 The anterior portion of the inferior maxilla is a 

 single piece, flattened above and below and widened 

 anteriorly. The anterior border is convex and con- 

 tains six alveoli (in Ruminantia eight), which receive 

 the inferior incisor teeth. Just posterior to the 

 incisor teeth are two cavities, one on either side, which 

 contain the canine teeth. On the external surface, 

 about midway between the canine and first molar 

 teeth, is a foramen (Fig. 1-27), the inferior orifice 

 of the dental canal, which transmits the inferior 

 dental artery and inferior division of the fifth pair of 

 nerves, which supply the teeth with sensation. At 

 this place the bone is constricted to form a neck. 

 Superiorly there is a ridge, more or less sharp, which 

 helps form the inferior interdental space. 



SINUSES. 



Sinuses are winding cavities in the bones of the 

 face communicating freely with each other, and with 



