Dangerous angle of the middle cranial fossa injury at penetration of arthroscope in a superior joint space of the temporomandibular joint

Osteological consideration

Abstract

Several reports have suggested the risk of injury to the middle cranial fossa at arthroscope penetration into the superior joint space of the temporomandibular joint. However, there has been no anatomical study on the safe angle of penetration into the superior joint space. In this study, we investigated 96 mandibular fossa of Japanese dry skulls with three dimensional measurements in order to decide on the dangerous angle for injury to the fossa when the arthroscope penetrated the lateral roof of the fossa.
The results showed that in the horizontal plane, the dangerous angle was an inclination of at six degrees to the back, and 18 degrees downward in the frontal plane in the frontal plane. The histogram of the measurements showed that an inclination to the back of over 30 degrees and downward 0 to 10 degrees gave freedom from danger in arthroscope penetration.