Comparison of Bone- and Tooth-Anchored, Bone-Anchored, and Surgically Assisted Bone-Anchored Rapid Palatal Expansion: a Pilot Retrospective CBCT Study

Introduction: The purpose of this retrospective pilot study is to evaluate and compare the transverse dental and skeletal changes in three different approaches to miniscrew-assisted rapid palatal expansion (MARPE) including bone- and tooth-anchored (BTAME), bone-anchored (BAME), and surgically assisted bone-anchored maxillary expansion (SRBAME) maxillary expansion. The secondary purpose is to formulate new research questions and develop methods for future MARPE studies. Materials and Methods: Pre- (T1) and post-expansion (T2) Cone Beam Computed Tomography (CBCT) radiographs from 12 patients treated with BAME (median age = 15.5, 95% CI 14.0-18.1), 7 patients treated with BTAME (median age = 19, 95% CI 14.8-26.9), and 5 patients treated with SRBAME (median age = 38, 95% CI 21.6-56.0) were included in the study. All skeletal, alveolar, and dental changes were standardized using suture opening at first molar for intergroup comparisons. There were seven linear and two angular measurements evaluated at the first premolar, second premolar, first molar, and second molar levels for intra- and intergroup comparisons. Results: BTAME and BAME approaches both resulted in significant changes to transverse skeletal and alveolar transverse dimension with some dental tipping. Alveolar bone tipping at the first molar level in BAME was greater than in BTAME (p0.05) while it was significantly greater in the anterior than posterior in BAME (p Conclusions: Both BTAME and BAME result in significant transverse skeletal, alveolar, and dental expansion. BAME resulted in greater alveolar bone bending while BTAME resulted in greater dental tipping. Among the three groups, BTAME suture opening was closest to parallel from anterior to posterior. Contribution of skeletal expansion to intermolar width increase is more favorable in BAME than BTAME.