Comparison of tooth-borne and hybrid devices in surgically assisted rapid maxillary expansion: A randomized clinical cone-beam computed tomography study.

PURPOSE: The objective of this 2-arm, parallel, single-center trial was to compare the skeletal, dental, and periodontal effects of tooth-borne (TB) and hybrid devices in surgically assisted rapid maxillary expansion (SARME).

MATERIALS AND METHODS: Twenty consecutive patients (9 male and 11 female) with skeletal transverse maxillary deficiency seeking treatment at the Department of Orthodontics at Istanbul University in Istanbul, Turkey, were randomly assigned to 2 groups (10 patients each). Hybrid devices were inserted in the first group and TB (Hyrax) devices in the second. All of the patients had undergone SARME operations, which were carried out by the same surgeons using the same procedure (a Le Fort I osteotomy with pterygomaxillary dysjunction). All of the patients had similar transverse deficits, and 7 mm of expansion was achieved in all of them over 14 days. CBCT was carried out preoperatively (T0), at the end of the active expansion phase (T1), and after 6 months of retention (T2). Measurements were made using Mimics 16.0.

RESULTS: Anterior skeletal maxillary widening parameters increased significantly in the T0-T1 and T0-T2 periods in the 2 groups (P = 0.001). There was significantly less dental expansion anteriorly with the hybrid devices (T0-T2: 4.03 mm vs. 6.29 mm). The first molars tipped buccally more in the group with TB devices during the T0-T1 phase (P = 0.029) and moved upright more than those in the group with hybrid devices during the retention phase (P = 0.035). Dental tipping, buccal alveolar bone resorption, and root resorption were observed significantly more often with the TB devices.

CONCLUSION: Hybrid RME devices, with similar skeletal effects, different dental movement patterns, and fewer dental and periodontal side effects, thus appear to be a beneficial alternative to TB devices for SARME procedures.