Morphometric analysis of temporomandibular joint elements

Abstract

Purpose: To study the morphology of temporomandibular joint (TMJ) elements and examine the feasibility of a novel biofidelic articular disc casting technique.

Methods: 18 formalin-fixed cadavers (77.8% female, 22.2% male) with mean (SD) death age of 71.9 (13.7) years were used for this study. In each specimen the masseter muscle, mandibular ramus, and articular disc were dissected bilaterally and measured for length, width, and thickness. All anatomic measurements were made using a digital slide caliper (Hawk Inc., Cleveland, OH). Further, a novel method for the creation of biofidelic articular disc models was established through trial and error. Models were measured for accuracy against their biological counterparts.

Results: Left articular disc length and thickness were inversely correlated (r = -0.58, p < 0.049). Direct correlations existed between right disc and ramus thickness (r = 0.56, p < 0.039), masseter length and thickness (r = 0.59, p < 0.009), and masseter width and thickness (r = 0.66, p < 0.003). Comparison of the model measurements with their biological counterparts found no significant differences.

Discussion: These observed correlations between elements of the TMJ hold relevance for oral-maxillofacial surgeons and researchers examining disorders of the TMJ. Additionally, our casting technique proved accurate in modeling human articular discs.

Keywords: Articular disc; Joint disorder; Plastic casts; Temporomandibular joint; Temporomandibular joint disorder.