A method for quantitatively determining temporomandibular joint bony relationships.

The spatial relationship of the mandibular condyle to the temporal component of the TMJ is determined quantitatively from lateral tomograms using a new method of measuring specific areas of the joint space. Condyle position along the posteroanterior axis of the joint is expressed as a ratio of the posterior joint space area divided by the anterior joint space area (the P/A ratio). A description of the method, as used in a clinical evaluation of 50 asymptomatic tMJs, and a statistical evaluation of the method's reproducibility and accuracy are given. The method was found to have both high reproducibility and high accuracy.