Aim: To present the experience with bimaxillary expansion using Surgically Assisted Rapid Maxillary Expansion (SARME) and Mandibular Midline Distraction (MMD).

Methods: A retrospective study using the records of all bimaxillary expanded patients treated at the Erasmus University Medical Center, Rotterdam was conducted. Measurements consisted of: radiographs (panoramic, lateral and PA-ceph and Cone Beam-CT), dental casts, conventional photographs. Following surgical procedures, type of device used, activation and distraction time and rate, and treatment difficulties/complications were recorded.

Results: 36 patients were included, 17 (47%) females and 19 (53%) males, mean age 26(±11.0) (range: 13–53). There were 8 congenital deformity patients. In 35 of the MMD the device was bone-borne, 1 was tooth-borne. Regarding SARME 13 were bone-borne, 23 were tooth-borne. Additional surgeries were: bilateral sagittal split osteotomy (BSSO) in 8; LeFort I osteotomy in 7; genioplasty in 2; LeFort III distraction in 1. Encountered treatment difficulties/complications were: (transient) nerve damage; distractor-, soft tissue- and tooth-related.

Discussion/conclusion: Bimaxillary transverse expansion using distraction osteogenesis is an alternative to combined extraction and orthodontic treatment ^. Our experience with bimaxillary expansion is good, it avoids extraction therapy and results in a superior functional and esthetic outcome. The therapy itself and the use of the device, however, caries certain risks. Future perspectives include a prospective controlled trial on MMD and bimaxillary expansion to further optimize treatment protocol and to minimize complications.

Conflict of interest: None declared.