Left-Right Asymmetries and other Common Anatomical Variants of Temporomandibular Articular Surfaces

Abstract

The purpose of the study was to investigate left-right asymmetries and other anatomical variants of temporomandibular articular surfaces. Digital photography and macroscopic observation were used to gather information about the shape, size, orientation and degeneration of temporomandibular articular surfaces of 100 skull bases and 100 mandibles. Left-right asymmetries in shape, size, orientation and degeneration were found in 39.5, 26, 16 and 31.5% of the mandibular surfaces respectively. The glenoid fossae showed left-right asymmetries in size, orientation and degeneration in 4.1 and 22.5% of cases respectively. Left-right asymmetries in orientation were found in 24% of the articular eminences. Anatomical variants of the mandibular articular surfaces were found as differences in shape: the majority had horizontal oblong outlines and rounded frontal outlines; one fifth showed pear-shaped horizontal outlines and flat or ridge-shaped frontal outlines. The important incidence of left-right asymmetries and anatomical variants of temporomandibular articular surfaces must be considered when observing and treating temporomandibular dysfunction. It can be expected that these asymmetries and anatomical variants may have arthrokinematic consequences for treatment of temporomandibular dysfunction.