The Relationship of the Articular Eminence with the Mandibular Fossa: Implications for Temporomandibular Joint Mechanics

Abstract

The temporomandibular joint varies from most joints in that it is ginglymoarthrodial, both a hinge and a gliding joint. Early opening of the mouth produces a rotational movement at the joint; however, with wide mouth opening, the mandibular condyle translates anteriorly beyond the articular eminence. In some circumstances, the translation of the mandibular condyle over the articular eminence produces a dislocation of the mandible with concomitant spasm of local musculature, thereby holding the mandible in an open position. In certain circumstances, conservative treatments may prevent future dislocations. However, occasionally, surgeries such as eminectomy may be warranted. Because of the aforementioned relationship of the articular eminence with the movement of the mandible, the anatomy of the articular eminence warrants study in order to attain a better understanding of the temporomandibular joint mechanics. Therefore, this study assessed the angle formed by the anterior and posterior boundaries of the articular eminence and the angle formed between the posterior border of the mandibular fossa with the anterior border of the mandibular fossa (i.e., the posterior border of the articular eminence)—angles A and B, respectively. A total of 102 left sides and 99 right sides were analyzed. The average angle A was 112.5±14.49° (Mean±SD) and the average angle B was 112.4±13.28°. Angles A and B were correlated (r=0.41; p<0.0001). Paired t‐tests revealed no statistically significant difference between angle A, bilaterally (t=1.543(80); p=0.1268). However, there was a statistically significant difference between left‐ and right‐sided angle B (t=4.045(77); p=0.0001). The results of this study suggest that there is bilateral asymmetry among mandibular fossae. Similarly, the anterior and posterior boundaries of the articular eminence do not differ significantly from side‐to‐side. Further study should incorporate the size of the articular eminence and mandibular fossa in relation to the angular data presented here.Support or Funding InformationWV Research Challenge Fund [HEPC.dsr.17.06] and [HEPC.dsr.14.13]This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.