The Contour of the Mandibular Fossa in the Sagittal Plane

Abstract

The mandibular (glenoid) fossa is of particular importance with regard to the biomechanics of the temporomandibular joint. In particular, the anterior aspect of the mandibular fossa, formed by the articular eminence, influences mandibular depression and protrusion. Accordingly, the mandibular fossa and articular eminence are common structures to undergo surgical alteration (e.g. eminectomy). Therefore, this study analyzed the contour of the mandibular fossa in the sagittal plane to improve the understanding of how the native shape of the mandibular fossa may be implicated in the biomechanics of the temporomandibular joint. The study assessed a total of 39 mandibular fossae via three‐dimensional models of human crania. The three‐dimensional crania models were manipulated such that the model could be split in the sagittal plane in the center of the mandibular fossa. Two‐dimensional renderings of the sagittal planes bifurcating the mandibular fossae were then utilized to perform geometric morphometric analysis utilizing 15 sliding landmarks spanning from the post‐glenoid tubercle to the apex of the articular eminence. Procrustes superimposition revealed a mean contour that when interpolated is given by the equation y ≈ 12.973x6 − 7.2434x5 − 10.861x4 + 4.2187x3 + 3.2365x2 − 0.3056x − 0.1303. Principle component analysis demonstrates 84.90% of the shape variance within two principle components (PC1=70.56% of variance; PC2=14.34% of variance). Also, the left‐ and right‐sided contours did not differ significantly (Mahalanobis distance=2.305; T2=54.2889; p=0.8042). The information presented here provides insight with regard to the average contour of the mandibular fossa as well as most likely contour variation. Therefore, this information may be applied in the context of joint biomechanics to better understand the function and limitations of the temporomandibular joint.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.