The stability of facial osteotomies. 1. The evolution of maxillary, mandibular and chin osteotomies

Surgical repositioning of the dento-skeletal components of the face, combined with appropriate orthodontic treatment, can be used to improve function and aesthetics. An extensive number of osteotomies are performed within the maxillofacial region. The most common of these are the Le Fort I osteotomy of the maxilla, the bilateral sagittal split osteotomy of the mandibular ramus, and the horizontal osteotomy of the anterior mandible. The attainment of three dimensional stability following corrective jaw surgery continues to be a major problem in the post-surgical period, in spite of the widespread adoption of rigid internal osteosynthesis. The evolution of these osteotomies to advance dento-skeletal components is traced from their inception to the present day and the concept of stability is explained (Part I). This serves as a prelude to an investigation into the stability of these procedures, undertaken in isolation or combination, to advance selected segments of the mid- and lower face (Parts 2, 3, 4, 5).