[Determination of the individual-optimal occlusion height in the edentulous mouth]

Foramen ovale, foramen mandibulae and foramen mentale, as shown in lateral radiographs of human cadaver heads bisected in the median-sagittal plane, can be placed simultaneously in every position of the mandible on the logarithmic spiral line devised by M. Moss. The individually optimal vertical dimension is that position of the mandible in which the foramina occupy the most central position on this spiral line; abduction and adduction of the mandible from this position cause a shift of the foramina to the periphery of the spiral line. Geometrically, loss in vertical dimension due to edentia can be computed from changes of the mandibular angle. Geometrical relationships were also shown between the distance from the foramen ovale to the foramen mandibulae, and other directly measurable distances on lateral cephaloradiographs.