THE BONES OF THE HEAD 



117 



which gives origin to the anterior belly of the digastric. Coin- 

 ciding with the position of the external oblique line there is the 

 internal oblique line or mylo-hyoid ridge. This commences near 

 the symphysis below the lower genial spine, and, passing obliquely 

 backwards and upwards, it terminates a little behind the last molar 

 alveolus. It gives origin to the mylo-hyoid muscle over its whole 

 length, whilst at its upper and back part it gives attachment to 

 some fibres of the superior constrictor muscle of the phar\-nx and 

 the pterygo-mandibular ligament. Below the posterior part of this 



Coronoid Process 

 Temporal Musde 

 Lingnla 



Inferior Dental Furamen 

 Buccinator 



Fossa for Submaxillary Gland 



Internal Oblique Line 



Fossa for Sublingual Gland 



Interna! - - - 

 Pterygoid 



Upper Genial 

 - - ' ' Spine and 

 Genio-hyo-glossus 

 Lower Genial 



Spine and 

 Genio-hyoid 



Mylo-hyoid Groove 



Digastric Impression and 

 Anterior Belly of Digastric 



Fig. 73. — The Left Half of the Inferior Maxillary Bone 

 (Internal View). 



ridge is the submaxillary fossa for the submaxillary gland, and above 

 fk& anterior part is the sublingual fossa for the sublingual gland. 

 t The superior or alveolar border is excavated into sixteen alveoli 

 or sockets, eight in each half of the bone, which correspond with 

 those in each superior maxilla. The outer surface of the alveolar 

 border, over the extent of the three molar alveoli at either side, 

 gives origin to some fibres of the buccinator. The inferior border 

 or base terminates, at either side, on a level with the anterior 

 border of the ramus. It projects more than the superior border, 

 and gives insertion on its outer aspect to a portion of the platysma 

 myoides. Near its termination it is marked by a short vertical 

 groove for the facial artery. 



