MARPE Improves Long-Term Stability of Maxillary Expansion in Adolescents.

Objective (s): To evaluate and compare the long-term skeletal and dentoalveolar outcomes of conventional rapid palatal expansion (RPE) and mini-screw-assisted RPE (MARPE) in adolescent patients.

Materials and methods: Fourteen patients were recruited from a cohort of patients previously treated with RPE or MARPE appliances with a history of > 10 years post-treatment. Of the initial larger sample population, these 14 patients agreed to return for a follow-up appointment. For the study purposes, the cone-beam computed tomography (CBCT) images acquired at pre-treatment (T0), after maxillary expansion and 6 months of retention (T1), and 10-year post-treatment follow-up period (T2) were utilized. The study variables obtained from the CBCT images comprised skeletal width, palatal suture assessment, buccal and palatal bone thickness, dental tipping, and alveolar bone bending measurements. Statistical comparisons were performed using Mann-Whitney U tests. The level of significance was set at p < 0.05 for all tests.

Results: MARPE resulted in more stable skeletal expansion and fewer dental side effects compared to RPE treatment. Patients treated with RPE exhibited an 80% relapse in buccal maxillary width at the premolar after 10 years, compared to a 30% relapse among those treated with MARPE. Several additional parameters showed enhanced relapse in the RPE group compared to the MARPE group, suggesting MARPE treatment results in improved long-term dentoskeletal stability.

Conclusion: Treatment with MARPE resulted in more stable long-term skeletal expansion and fewer dental side effects compared to conventional RPE 10 years after the completion of orthodontic treatment.