부산대학교 도서관

A concavity has been sometimes found on the posterior bony surface of the condylar head of the patients with TMJ dysfunction by lateral TMJ radiography. In order to define the meaning the radiographic sign indicates, incidence by age group and location of the concavity were investigated on the selected lateral TMJ tomograms of 159 patients with TMJ dysfunction.With an incidence of about 30%, the concavity was found on the condylar head of the patients, evenly in every age group. The result indicated that the concavity was not merely a aging, but probably an adaptive change in the patients with TMJ dysfunction.Almost all of the concavities located at the upper half of the posterior surface of the condylar head and about 40% of them was opposite to the posterosuperior wall of the articular fossa and 60% to the postglenoid process, in the closed mouth position, though the bony outer surfaces of them were rather not in paralell with each other.In relation to the articular eminences, at the maximum open mouth position in patients without locking, about one third of concavities (14TMJs) faced to them, as if they were affected by each other, putting a meniscus between them. Another one third translated anterosuperiorly beyond the apex of the articular eminences. However, it was not to be hard to suppose that the condylar head was scraped out by the articular eminence when it returned back into the articular fossa. Remain one third had no interrelations with the articular eminences.In the present study, it was suggested that the concavity on the posterior bony surface of the condylar head was probably an adaptive change to abnormal jaw movements of the patients with TMJ dysfunction, and some might be formed in relation to the anterior slope of the articular eminence or tuberculum, locating at the level next to the top of condylar head.