Comparison of tooth- and bone-borne devices in surgically assisted rapid maxillary expansion by three-dimensional computed tomography monitoring: transverse dental and skeletal maxillary expansion, segmental inclination, dental tipping, and vestibular bone resorption.

Comparison of bone-borne (BB) versus tooth-borne (TB) distraction in surgically assisted rapid maxillary expansion, secondary variables were bipartite (2S) or tripartite (3S) osteotomy, pterygomaxillary osteotomy (+PP) or not (jPP), and age (920 years old [920] and G20 years old [G20]). Fifty patients received three-dimensional computed tomography examination preoperatively and after expansion; 24 had BB, and 26 had TB distraction. Predefined preoperative landmarks versus postexpansion positions were assessed in multiplanar viewing. Bone-borne devices had bigger overall skeletal and dental maxillary expansion declining from anterior to posterior, more asymmetric expansion, less vestibular bone resorption, and less dental tipping; TB devices showed similar dorsal decrease in transverse skeletal and dental maxillary expansion from anterior to posterior, more vestibular bone resorption, particularly in the premolars, and more dental tipping. Bone-borne 3S +PP G20 had the biggest decrease in transverse skeletal widening and biggest segmental outward inclination; BB 3S +PP 920 had the biggest decline in transverse dental widening; TB 2S YPP G20 had the biggest segmental inward inclination; BB 2S YPP 920 had the biggest dental tipping; BB 2S G20 had the biggest vestibular bone resorption in molars; and TB 3S 920 and BB YPP had the biggest vestibular bone resorption in premolars. There was a significant correlation between transverse widening and segmental inclination; that is, a bigger amount of transverse widening provokes less segmental inclination.