An evaluation of three-dimensional facial changes after surgically assisted rapid maxillary expansion (SARME)

Abstract

Background: The purpose of the study was to evaluate the three-dimensional (3D) facial changes following surgically assisted rapid maxillary expansion (SARME). In 15 skeletally mature patients with maxillary transverse deficiency the planned maxillary expansion (on average 8.8 mm ± 2.3 mm) was achieved with bone-borne palatal distractor. The 3D optical scans of the facial surface were obtained before and 6 months after SARME and compared with cephalometric and regional analysis to evaluate the soft-tissue changes. Findings. The largest differences between the pre- and post-operation scans were observed for the paranasal and cheek area (1.4 ± 1.0 mm) in the lateral direction with a soft-to-hard tissue ratio of 0.22. Significant differences occurred for an increased nasal width, a decreased upper-face height with an unchanged lower height, an increased vertical philtrum height and an increased nasolabial angle. A significant increase in the facial profile angle was also observed, resulting in an increased facial convexity and anterior displacement of the upper-lip area. Conclusions. We have confirmed the widening of the nose and increased projection in the cheek and paranasal area in the lateral direction after maxillary expansion, while we found facial convexity increases, reflecting the underlying advancement of the maxilla.