Combined orthodontic and orthognathic surgical treatment for the correction of skeletal anterior open-bite malocclusion: a systematic review on vertical stability.

PURPOSE To evaluate vertical stability after combined orthodontic surgical treatment of skeletal anterior open-bite malocclusion. MATERIALS AND METHODS A literature search was performed to locate studies pertaining to vertical stability after combined orthodontic surgical treatment of skeletal anterior open-bite malocclusion. Data from the identified studies were extracted and assessed for quality. Short-term and long-term changes in the following variables were evaluated: overbite; mandibular plane, palatal plane, and intermaxillary angles; and anterior facial height. RESULTS Nine studies, all retrospective, were appropriate for inclusion after review. The postoperative follow-up period ranged from 1 to 18 years. A wide variation was present for post-treatment changes and relapse. Dentally, overbite changes showed a wide variation, with more long-term relapse observed in patients after Le Fort I osteotomy. Skeletally, the mandibular plane and intermaxillary angles showed greater long-term relapse after bimaxillary surgery than after Le Fort I osteotomy. The same trend was seen for the post-treatment increase in anterior facial height. In contrast, the palatal plane seemed to remain rather stable. CONCLUSIONS Vertical relapse is a characteristic in a certain number of patients after combined orthodontic surgical treatments regardless of surgery type. This can be observed dentally by an opening of the bite and skeletally by an increase in the mandibular plane and intermaxillary angles during long-term follow-up. Long-term skeletal relapse seems to be more common after bimaxillary surgery.