The stability of anterior open bite closure after Bi-maxillary osteotomy

Abstract

<b>Introduction</b>: The aim of this study was to evaluate the long-term success rate of combined surgical-orthodontic therapy of skeletal anterior open bite. <b>Methods</b>: 11 patients with an anterior open bite treated with a combined surgical-orthodontic therapy were retrospectively analysed via lateral cephalometric radiographs and models before treatment, 7–10 days after surgery(T1), one year post-operatively(T2) and two years post-operatively(T3). <b>Results</b>: Ten patients continued to experience a positive overbite at T2. This decreased to 8 at T3. Three patients experienced relapse and had a negative overbite at T3. The average pre-treatment overbite was greater in the positive overbite group compared to the relapse group. Spearman's correlation analysis revealed a correlation between pre-operative maxilla-mandibular plane angle (MMPA) with the overall change in overbite. <b>Conclusions</b>: In conclusion, combined orthodontic-surgical treatment achieves good results for anterior open bite. Patients with a high pre-operative MMPA have a higher risk of relapse. Lower anterior facial height ratio to total anterior facial height (LAFH:TAFH) and the amount of impaction do not significantly contribute to the risk of relapse. Long term stability of overbite for anterior open bite patients should cover around 75% of patients.