Location of the mandibular foramen in panoramic radiographs.

The reliability of two panoramic x-ray machines (Philips Orthoralix SD Ceph and Gendex Panelipse II) for determination of the location of the mandibular foramen was studied with the use of human dry mandibles. A significant correlation was found between the location of the mandibular foramen in the radiograph and the narrowest anteroposterior dimension of the ramus. A linear logistic regression equation was developed that could predict the actual location of the mandibular foramen from the radiographs. This finding will improve treatment planning of surgical splitting or fracturing of the ramus in cases that require orthognathic surgery provided the surgeon is aware of which panoramic machine was used. The Philips Orthoralix SD was found to be more reliable for this purpose than the Panelipse II (R2 = 0.94 and R2 = 0.87, respectively, in the vertical dimension and R2 = 0.87 and R2 = 0.75, respectively, in the horizontal dimension.