Objectives: This study aimed to evaluate, via a computed tomography, the direction and magnitude of the segmental tilting that may occur after SARME in patients having transverse maxillary deficiency.

Patients and methods: Thirty adult patients having transverse maxillary deficiency greater than 5 mm were treated by surgically assisted rapid maxillary expansion (SARME). The procedures consisted of bilateral zygomatic buttress and midpalatal osteotomies combined with the use of a tooth-borne orthopedic device postoperatively. Axial and coronal images were made before and 6 months after SARME to evaluate the segment tilting.

Results: The greatest expansion has occurred in the most inferior (5.4 ± 1.13 mm) and anterior (4.0 ± 1.26 mm) regions of the maxilla. The expanded segment tilted outward inferiorly and anteriorly in coronal and axial images, respectively. The segment tilting was 2.03 mm (2.27%) inferiorly and 3.07 mm (12.81%) anteriorly.

Conclusions: It can be concluded that, an outward tilting occurs in the most inferior and anterior portions of maxilla during the SARME procedures. So, the direction and magnitude of such segmental tilting must be considered preoperatively when determining the surgical objectives.