ISSN:
0362-2525
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The dog mandible has three joints - two temporomandibular and one symphyseal joint. In studies of jaws and their mechanics usually only the temporomandibular joints are considered. The symphysis is consistently neglected and because of this, remarkable features of the temporomandibular joints have never been noted.The symphysis has special connective tissue arrangements and its own vascular and nerve supply. Along the anterosuperior part of the symphysis, a strip of fibrocartilage, and running more or less parallel to it, strong cruciate ligaments bind the symphyseal plates together. Small arteries run into the symphyseal joint and it is drained by an anastomosing venous plexus. The posterior, ligamentous, portion is laced with a profuse network of nerves.The temporomandibular joint is unusual in that its joint disc is powerfully anchored to the skull medially and to the outer pole of the mandibular condyle laterally. The temporomandibular joint disc thus acts as a ligament that halts lateral movement of the condyle just as the carnassial teeth are aligned for cutting function. As the mandible moves laterally, the space between the posterior ends of the symphyseal plates widens: at the same time it narrows anteriorly. The cruciate ligaments control this movement and stabilize the symphyseal joint by preventing direct lateral displacement of the symphyseal plates. The fibrocartilage cushions this movement and also mediates rotational movements about the longitudinal axis of the mandible when crushing molar teeth come into function.
Additional Material:
22 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jmor.1051160103
