A 40-year-old man sought treatment for a progressive change in occlusion (Figure 1), deviation of chin, and swelling in the left preauricular area that developed over the past several years. He denied any preexisting joint disease and trauma to the area. His medical, surgical, family, and social histories were noncontributory. The patient did not take any medications. The patient reported seasonal allergies but no known drug allergies. The review of systems was unremarkable. The extraoral examination revealed a well-nourished, well-developed man with mild tenderness and swelling of the left preauricular area, no appreciable joint sounds or crepitus, maximum incisal opening of 60 mm, and deviation of chin to the right at rest and on opening.