On 108 skulls specimens with malocclusion and 30 skulls specimens with complete edentulism from the craniological collection of the Department of Normal Anatomy of the Military Medical Academy named after S.M. Kirov, a comprehensive study of the morphometric characteristics of the articular surfaces of TMD joint was carried out. The peculiarities of petrotympanic fissure topography in various forms of the brain skull were also evaluated to establish the possible anatomical causes of Costen's syndrome. The fact of the variability of the petrotympanic fissure topography within the mandibular fossa has been established, the fissure can be located in back and mesial parts of this fossa or it takes intermediate position. The option of petrotympanic fissure topography in mesial parts of the mandibular fossa is a predisposing anatomical factor for Costen's syndrome and can be found at different neurocranium forms but predominantly at hypsicranial. The immediate cause of the Costen's syndrome can be occlusal-caused diseases followed by TMD joint dysfunction. In this case, the changes of articular surface of TMD joint take place, in particular, a decrease in size of the head of mandible, its pathological displace, capsule stretching, and compression of chorda tympani.