Differences between the functional matrices in anterior open-bite and in deep overbite

Abstract

The position of the three neural foramina describing the course of the inferior alveolar nerves was studied, with the aid of a previously determined logarithmic spiral, in cases of anterior open-bite and deep overbite. In anterior open-bite, the position of the foramen ovale was shown to be characteristically lower on this spiral than it is in any other condition studied; indeed, it is a diagnostic characteristic. The significance of this finding in the discussion of the problems of mandibular size and shape in these conditions was discussed. The etiologic role of periosteal and capsular functional matrices in the development of anterior open-bite was analyzed, and capsular matrices, with their related processes of passive translative growth, were held to be developmentally primary. Finally, an associated difference in the spatial location of the oral space in anterior open-bite was discussed. In essence, anterior open-bite was found to be a condition associated with specific spatial and developmental abnormalities of the oral functioning space, acting as a capsular matrix. All observed skeletal tissue changes are but secondary, compensatory, and mechanically obligatory responses to the morphogenetically and temporally prior alterations of this capsular matrix. Clinicians should carefully differentiate between the causes of an observed deformation of the orofacial skeleton and its etiologic factors. In anterior open-bite, they are completely different.