<uO ANATOMY. 



Sublingual Fossa, near the genial tubercles, for the sublingual gland. 



Fossa, below the sublingual, for the anterior belly of the digastric muscle. 



Submaxillary Fossa, below the ridge, for the submaxillary gland. 



Describe the Kami of the Inferior Maxillary. The rami, or ascending 

 portions of the bone, are 2 in number, and each present the 



Coronoid Process, anteriorly, for the insertion of the temporal muscle. 



Condyloid Process, posteriorly. Its condyle articulates with the glenoid 

 fossa of the temporal bone, its neck receives the insertion of the external 

 pterygoid muscle, its tubercle has attached to it the external lateral liga- 

 ment of the lower jaw. 



Sigmoid Notch, a deep depression separating the above-named processes 

 from each other, and crossed by the masseteric vessels and nerve. 



Groove, on the coronoid process internally, and prolonged downwards upon 

 the body, for the attachment of the buccinator muscle. 



Ridges, on the external surface, for the insertion of the masseter. 



Spine, a projection on the internal surface, for the attachment of the internal 

 lateral ligament of the jaw. 



Inferior Dental Canal, opening behind the spine, lies within the ramus and 

 body of the bone for the inferior dental vessels and nerve. It communi- 

 cates with each alveolus and with the mental foramen. 



Mylo-hyoid Groove, below the spine, for the mylo-hyoid vessels and nerve. 



Rough Surface, behind the groove, for the internal pterygoid muscle. 



Angle of the Jaw, at the junction of the posterior body of the ramus with 

 the inferior border of the body, for the insertion of the masseter and in- 

 ternal pterygoid muscles, and the stylo-maxillary ligament. 



Describe the Articulations and Development of the Inferior Max- 

 illary bone. It articulates with one pair of bones, the temporal. It is the 

 earliest formed bone in the body except the clavicle, and is probably developed 

 by 2 centres, one for each lateral half, the two halves coalescing at the 

 symphysis about the 1st year of age. In adult life the ramus arises almost 

 vertically from the body, and the dental canal lies about the middle of the 

 body. In old age the ramus extends obliquely backwards, the angle becoming 

 very obtuse ; and the alveolar portion being absorbed, the dental canal is near 

 the superior border. 



What Muscles are attached to the Inferior Maxillary? They 

 number 15 pairs, the masseter, internal and external pterygoids and temporal, 

 4, to the ramus ; the genio-hyo-glossus, genio-hyoid, myio-nyoid, digastric, 

 and superior constrictor, 5, to the internal surface of the body ; the depressor 

 labii inferioris, depressor anguli oris, leyator menti, orbicularis oris, platysma 

 myoides, and buccinator, 6, to the external surface of the body. 



