MAXILLARY EXPANSION AND STABILITY IN THE ORTHONTIC-SURGICAL TREATMENT OF SKELETAL ANTERIOR OPEN BITE

Objective: Aim of this study is to analyze retrospectively the stability of the surgical/orthodontic treatment of skeletal open bite in relation to the skeletal classification and treatment proposed. The role of surgical maxillary expansion is analyzed in relation to long-term stability. Materials & Methods: Twenty patients presenting anterior skeletal open bite were undergone Le Fort I osteotomy alone (6 pts), bimaxillary surgery (12 pts) or bilateral sagittal split mandibular osteotomy (2 pts). Bipartition of the maxilla was carried out in five cases, and a midline osteotomy of the palate with a V -shaped anterior osteotomy was performed in one more case. Rigid internal fixation was used. Follow-up was from 1 to 10 years (mean 4 years). Records analyzed were pre-, post-surgical and follow-up cephalometric radiographs and dental models. Results: Eighty-five percent (17/20) of the patients had stable clinical and cephalometric results. Three patients experienced dental or skeletal relapse: in these patients the relapse was related to a recurrence in the palatal transverse dimension, which was expanded during orthodontic alignment. Transverse dimension of the maxilla was more stable in pts who underwent to a maxillary partition. Conclusions: Stability of surgical treatment of skeletal open bite seems to be related to a proper diagnosis and a surgical plan which must pay attention to the management of maxillary transverse diameter