MANDIBLE 



109 



zygomatic process of the temporal bone, completing the 

 arch. 



The Mandible, forming the lower jaw, is horseshoe in shape, 

 with vertical processes at the ends. The body supports on its 

 upper border the lower row of teeth, and near the middle line 

 on the outer surface is the mental foramen through which the" 

 mental nerve emerges. In the middle line of the body a faint 

 ridge can be seen, the symphysis, indicating that the bone was 

 developed in two halves and fused in the middle line. On the 



Left 



Left Condyle 



Condylar 

 Tubercle 



Impression for Temporal 

 Muscle 



Incisor Fossa 



AJental Protuberance ,' 

 Mental Tubercle 



Posterior 

 --Border of Ranms 



Angle 



Mental Foramen 



FIG. 44. THE INFERIOR MAXILLA (MANDIBLE). 



inferior border on each side of the symphysis is the digastric 

 fossa, a small concave surface for the digastric muscle, and on 

 the inner surface of the bone is found an oblique line or ridge, 

 the mylo-hyoid ridge, slanting from above downwards and 

 forwards. 



The posterior vertical portions are called rami; they pass 

 upwards from the posterior extremities of the body of the bone 

 forming the angle of the jaw, which varies with different 



