Rotational fulcrum and dentoskeletal changes after rapid palatal expansion with tooth-bone-borne (MARPE) and tooth-borne appliances in post-pubertal patients.

Abstract

Objectives: To identify the rotational fulcrum (RF) and to evaluate the skeletal and dentoalveolar effects after rapid palatal expansion (RPE) with tooth-borne and tooth-bone-borne (MARPE) appliances.

Materials and methods: 31 patients were selected (MARPE group: n = 14, age 16.2 ± 2 years; hyrax group: n = 17, age 14.7 ± 0.8 years) with RPE indication and having cone-beam computed tomography before (T1) and after RPE (T2) and after 6 months of retention (T3).

Results: In the MARPE group, the RF was at or above the frontozygomatic suture (FZS), whereas in the hyrax group, it was at or below the FZS. The skeletal response rates were 70% (2°) and 33% (1.09°); alveolar response rates, 18% (0.52°) and 20% (0.68°); and dental response rates, 12% (0.35°) and 47% (1.54°) in the MARPE and hyrax groups, respectively, with a significant difference between groups in skeletal (P = .005) and dental (P < .001) regions. After retention, no significant difference was found between groups.

Conclusions: Although MARPE resulted in a higher RF in the coronal view, both techniques effectively corrected transverse discrepancies with similar stability. Considering the between-group differences in relation to skeletal and dentoalveolar response, MARPE should be used for cases in which minimal compensatory tooth movement is desired.