(-.4 



THE SKELETON 



l>v tlK' condyle, whieh is connected with tlic ninius liy a somewhat constricted 

 portion, the neck. 



The condyle is oval in shape, Avith its long axis transverse to the upper l)order 

 of the ramus, but oblique with regard to the median axis of the skull, so that the 

 outer is more anterior than the inner angle, and presents the condyloid tubercle 

 for the external lateral ligament of the temporo-mandibular articulation. The 

 (X)nvex surface of the condyle is covered with cartilage and rests in the glenoid 

 fossa; the neck is flattened in fntnt and presents a pit, for the insertion of a portion 

 of the external ptcri/fiaid muscle. The superior border of tlie ramus is known as the 

 sigmoid notch ; it is terminated anteriorly by the coronoid process. This is a 

 })t)inted process with two borders and two surfaces; the inner surface presents a 

 ridge, commencing at the tip, and becoming continuous with the inner edge of 

 the alveolus. To this ridge, to the area of bone in front of it and the tip of the 

 coronoid process, the temporal muscle is inserted; its outer surface affords attachment 

 to the masseter and a few fibres of the temporal. The anterior border of the ramus 

 is continuous with the external oblique line on the body of the bone. 



Blood-supply. — The mandible is very vascular, and receives a large supply 



Fig. 74. — The Mandible. (Inuer view.) 



External 

 pterygoid 



Capsule 



MANDIBULAR 

 SPINE 



MANDIBULAR 



FORAMEN 



Spheno-mandi- 



bular ligament 



Superior 



constrictor 



Mylo-hyoid 



groove 



Internal 

 pterygoid 



Stylo- 

 mandibular 

 ligament 



GROOVE FOR SUB- 

 LINGUAL GLAND 

 Genio-hyo- 



'^ I glossus 



Genio-hyoid 



Mylo-hyoid 



INTERNAL OBLIQUE LINE 



GROOVE FOR SUBMAXILLARY GLAND 



from the mandibular branch of the internal maxillary artery. This constitutes its 

 main supply. It receives twigs also from the faciid artery. 

 It gives attachment to the following muscles : — 



Buccinator. 



Depressor labii inferioris. 



Depressor anguli oris. 



Levator menti. 



Genio-hyo-glossus. 



Superior constrictor of pharynx. 



Masseter. 



Orbiculari.' 



Internal pterygoid. 



External pterygoid. 



Platysma myoides. 



(lenio-hyoid. 



Mylo-hyoid. 



Digastric. 



Temporal. 



Ossification. — The mandil»le has six ]t(>ints of ossification for each lateral half. 

 All these, with the exception of one, are deposited in memlirane. The nuclei are 

 deposited very early (between the sixth and eighth week), and fuse so rapidly that 

 observations on the development of this bone are unusually difficult. 



