THE MANDIBLE 



97 



The condylar process consists of the condyle [capitulum mandibulae] and the 

 narrowed portion by which it is supported, the neck. The condyle is oval in 

 shape, with its long axis transverse to the upper border of the ramus, but oblique 

 with regard to the median axis of the skull, so that the lateral extremity, which 

 presents the condylar tubercle for the temporo-mandibular ligament of the 

 temporo-mandibular articulation, is a little more forward than the medial ex- 

 tremity. The convex surface of the condyle is covered with cartilage in the recent 



Fig. 121. — The AIandible. (Medial view.) 



External - 

 pterygoid 



Articular 

 capsule 



->.*..*12 



Lingula 



Mandibular 



foramen 



Spheno-mandib 



ular ligament 



Superior 



constrictor 



Mylo-hyoid 



groove 



Internal 

 pterygoid 



Stylo-mandibular 

 ligament 



Groove for sub- 

 lingual gland 

 Genio-glossus 



Genio-hyoid 



Digastric 



Mylo-hyoid Groove for submaxillary gland 



Mylo-hyoid line 



state, and rests in the mandibular fossa; the neck is flattened from before back- 

 ward, and presents, in front, a depression [fovea pterygoidea] for the insertion 

 of the external 'pterygoid muscle. 



The coronoid process, flattened and triangular, is continued upward from the 

 anterior part of the ramus. The lateral surface is smooth and gives insertion 

 to the temporal and masseter muscles; the medial surface is marked by a ridge 

 which descends from the tip and becomes continuous with the posterior part of 

 the mylo-hyoid line. On the medial surface, as well as on the tip of the coronoid 



Fig 122 — Mandible showing Relations of Meckel's Cartilage in Human Fcetus of 

 8 CM. Crown-Rump Length. (After KoUmann, Handatlas der Entwickelungsgeschichte.) 



Malleus 



Groove for teeth 



Incus 



Meckel's cartilage 



Annulus tym- 

 panicus 



process, the temporal muscle is inserted. The mandibular notch, the deep semi- 

 lunar excavation separating the coronoid from the condylar process, is crossed 

 by the masseteric nerve and vessels. 



Blood-supply.^Compared with other bones, the superficial parts of the mandible are not 

 so freely supplied with blood. The chief artery is the inferior alveolar which runs in the man- 

 dibular canal, and hence, as the bone is exposed to injury and sometimes actually laid bare in 

 its alveolar portion, it often necroses, especially if the artery is involved at the same time. 



