The anteroposterior effect of rapid maxillary expansion using bone-borne VERSUS tooth-borne expander: A comparative study

Abstract

Background: In orthodontics, slow, rapid, and surgically assisted maxillary expansions are commonly performed to correct maxillary constriction, posterior crossbite, and crowding. Ideally, this treatment approach is recommended in growing (i.e., pediatric and adolescent) patients, as it requires a mid-palatal suture that is not fully fused. There is limited understanding on the relative efficacy of bone- and tooth-borne expanders for maxillary expansion.

Aim: To assess and compare dentoskeletal changes in maxilla and mandible after RME using bone- and tooth-borne expanders in adolescent patients.

Materials and Methods: This study compares 18 subjects (10 females and 8 males, with an average age of 14.4±1.3 years) who received tooth-borne RME; and 18 subjects (12 females and 6 males, with an average age of 14.7±1.4 years) who received bone-borne RME. Specific three-dimensional landmarks were used in order to compare skeletal and dental changes in tooth-borne and bone-borne expanders. Data was analyzed using Shapiro-Wilk, Paired t, Wilcoxon, and Mann-Whitney tests, in addition to Pearson correlation. A P-value of less than 0.05 was considered significant in all statistical analyses.

Results: In the tooth-borne group the following parameters showed a significant difference after expansion (P <0.05 ): molar width, intermolar width, molar buccal tipping in the transverse plane, and Pog-FH in the vertical plane. In the bone-borne group, a significant difference after expansion (P <0.05 ) was recorded for the following parameters: linear intermolar relation, palatal bone width, intermolar width, and interpremolar width. Comparison of the post- ii expansion results of both groups revealed that the bone-borne group exhibited less molar buccal tipping.

Conclusion: There was significant transverse change reported after expansion in both the bone-borne and tooth-borne groups, with less significant of dental tipping in the former. Nevertheless, both groups displayed limited sagittal and vertical changes when correlated to the transverse changes.