[The contrivable purpose and anatomical foundation of condylo-pterygo-maxillo-oblique tomography]

It is obvious that the Schüller's position of X-ray film is not enough to examine the TMJ, because it is limited in anterior and posterior view of the joint. The CPMO tomograph contrived by the authors can demonstrate the external and internal view of the joint and the surrounding structures of the joint, particularly the external pterygoid muscle. Therefore, it would be a complement to the Schüller's position. Under cross reference of these two films, the whole view of the TMJ, the joint external pterygoid muscle, and the relationship of the occlusion could be seen in one film. Certainly, this discovery will be of great value in the diagnosis and treatment of the TMJ diseases. In this paper the data of the anatomical measurement of 30 skulls are introduced. According to the results, the best angle of the film plane and projection to the sagittal middle line of the cranial is 45 degrees. Some other angles of projection for the TMJ examination are compared and discussed.