The Mandibular Foramen

Abstract

The sagittal split ramus osteotomy is the most commonly used procedure to reposition the mandible surgically. Because it is more technically difficult and associated with a higher incidence of complications compared with other mandibular osteotomies, thorough knowledge of the anatomy of the mandibular ramus is a prerequisite. Anatomic measurements related to the mandibular foramen were obtained from 57 formalin-preserved non-Asian hemimandibles. As shown in previous reports, great variability was noted in the position of the mandibular foramen. However, these studies utilized Asian mandibles with a clear discrepancy in key anatomic measurements in comparison with the authors' data. This brings into question the validity of these earlier studies when applying their data to non-Asian groups. The "fade-out" point of the internal oblique ridge was found not to be a reliable anatomic reference for placement of the horizontal osteotomy along the medial ramus. Thus, familiarity with the described relationships of the mandibular foramen will assist in performing properly a sagittal split of the ramus and will reduce the chance for an unfavorable split.