612 



DISSECTION OF THE PTERYGOID REGION. 



maxillary vessels, with the auriculo- temporal and inferior dental 

 nerves, pass between the band and the minus of the jaw. 



Dissection. After the external lateral ligament and the capsule 

 have been examined, the interarticular fibro- cartilage will be exposed 

 by taking away the capsule on the outer side (fig. 221). 



The interarticular fibro-cartilage (fig. 2 2 1, 4 ) is an oval plate, 

 elongated transversely, and thinner in the centre, where it is 

 sometimes perforated, than at the margins. The upper surface fits 

 the articular hollow and eminence of the temporal bone, being 

 convex behind and concave in front ; and the lower is moulded to 

 the convexity of the condyle of the jaw. By the circumference 

 and attach- it is connected with the capsule ; and in front the external pterygoid 

 muscle is attached to it. 



This interarticular disc allows a double movement to take place 

 in the articulation, the condyle of the jaw revolving in the socket 



Dissection. 



Fibro- 

 cartilage 



shape, 



ments ; 



FIG. 220. LIGAMENTS OP THE 

 JAW INNER VIEW (Boim- 



GERY AND JACOB). 



1. Internal lateral ligament. 



2. Stylo maxillary. 



FIG. 221. A VIEW OF THE INTERIOR 

 OF THE TEMPORO-MAXILLARY JOINT 

 (BOURGERY AND JACOB). 



3. Stylo-maxillary ligament. 



4. Interarticular fibro-cartilage : the 

 dark intervals above and below the disc 

 are the synovial cavities. 



Two syno- 

 vial sacs. 



Stylo- 

 maxillary 

 ligament. 



Surfaces of 

 jaw 



and tem- 

 poral bone. 



formed by the fibro-cartilage, while the latter glides forwards and 

 backwards over the temporal articular surface. 



Two synovial sacs are present in the articulation a larger one 

 above, and a smaller one below the fibro cartilage. 



Another structure the stylo-maxillary ligament (fig. 221, 8 ) is 

 described as a uniting band to the articulation. This is a process 

 of the deep cervical fascia, which extends from the styloid process 

 to the hinder border of the ramus of the jaw ; it gives attachment 

 to the stylo-glossus muscle, and separates the parotid and sub- 

 maxillary glands. 



Articular surfaces of the bones. The condyle of the jaw has a 

 form resembling that of a part of a cylinder, with its axis directed 

 obliquely from without inwards and somewhat backwards. 



The upper articular surface is placed on the squamous part of 



