The purpose of this study was to investigate the radiographic images of Temporomandibular joint trouble patients. This study included 186 patients with the chief complaints of TMJ pain and dysfunction. Their age ranged from 17 to 68 years. All patients were identified in the department of Dental mary of College of Dentistry, Seoul National University, Apr. 1978 to Jun. 1979. The author has observed the radiographic variations of two positions of condylar head taken by modified transcranial oblique-lateral projection, which are one in centric occlusion and the other in 1 inch(2.54㎝) mouth open. The results were obtained as follows; 1. In centric occlusion, the distances and positional relationship between the summit of condylar head and the deepest point of articular fossa revealed more or less large variations; Normal range is of 37.9%, anterior displacement of 37.3% and posterior displacement of 22.6%. 2. In the horizontal movement of condylar heads when on 1 inch mouth open, it was revealed that normalrange was of 46.5%, anterior displacement of 12.3%, posterior displacement of 41. 1 %. 3. In the positional interrelationship of both condylar heads when on 1 inch mouth open, it was revealed that symmetry(71. 5%) occurred approximately 2.5 times as many as asymmetry. 4. In both centric occlusion and 1 inch mouth open, it was showed that almost all estimated figures were greater in male than in female, and in the horizontal movement of condylar head when on 1 inch open, it was showed that hypermobility was dominant in male and hypomobility in female.