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HEAD AND NECK 



dibular fossa, and anteriorly to the anterior margin of the 

 articular tubercle. Below, it is attached to the neck of the 

 mandible ; and between its upper and lower attachments it is 

 connected with the margins of the discus articularis. 



The temporo-mandibular ligament (O.T. external lateral] is 

 a strong triangular band which is attached above to the 

 lateral surface of the posterior part of the zygoma and to the 

 tubercle at the root of the zygoma. Its fibres run down- 

 wards and posteriorly to the neck of the mandible. 



The spheno-mandibular ligament (O.T, internal later at] is a 

 long membranous band which extends from the spine of the 

 sphenoid to the lingula and to the sharp medial margin of the 



Upper joint cavity 

 Discus articularis 

 Lower joint cavity \ 

 Capsule 



Tuberculum articulare 



Mastoid process 



Styloid process 



FIG. in. Section through Temporo-mandibular Joint. 



mandibular foramen. It is not in direct relationship with the 

 joint. Above, it lies medial to the external pterygoid muscle 

 and the auriculo-temporal nerve ; lower down, the internal 

 maxillary vessels intervene between it and the neck of the 

 mandible ; whilst, still lower, the inferior alveolar vessels and 

 nerve are interposed between it and the ramus of the mandible. 



The stylo-mandibular ligament has been noticed already. It 

 is a fibrous band, derived from that portion of the deep 

 cervical fascia which forms a part of the capsule of the 

 parotid gland. It is attached above to the styloid process, 

 and below to the angle and posterior border of the ramus of 

 the mandible, between the internal pterygoid and masseter 

 muscles. 



An examination of these ligaments will show that very 



