Evaluation of skeletal effects and alveolar bone loss following microimplant-assisted rapid maxillary expansion using cone-beam computed tomography in late adolescents and young adults

Objective: The aim of this retrospective study was to evaluate the skeletal and dental effects of microimplant-assisted rapid maxillary expansion (MARPE) and alveolar bone loss using cone beam computed tomography (CBCT) in late adolescents and young adults. Materials-Methods: CBCT images of 21 individuals (7 males-4 females) who treated with MARPE and cervical vertebral maturation greater than stage 4 were selected from the archive. CBCT scans had been taken before (T0) and 3 mounths after (T1) the MARPE. Skeletal, dental and alveolar bone paramethers were measured on images, T0-T1 were compared. Paired sample t-test was used for dependent variables, independent sample t-test was used for independent variables, Pearson correlation analysis was used for correlation evaluation. Results: Statistically significant differences were found between T0-T1 measurements in skeletal and dental paramethers. At T1, the midpalatal suture expanded in anterior more than posterior. Dental expansion was more than palatal expansion but there was no statistical significance between them (p=0.459). The relationship between the palatal and the dental expansion and the relationship between the difference in alveolar bone inclination and tooth inclination were evaluated and no significant difference was found. Buccal cortical bone thickness decreased between T0-T1, but this decrease wasn't statistically significant. After expansion, buccal alveolar bone height decreased significantly. There was an increase in the amount of dehiscence between T0-T1, but the increase in the amount of dehiscence and fenestration wasn't statistically significant. Conclusion: With MARPE, the maxilla shows a skeletal V-shaped opening in the horizontal plane and an inverted V-shaped opening close to parallel in the coronal plane. Increased inclination of abutment teeth is associated with alveolar bone bending, not dental tipping. Vertical bone loss was found in the buccal alveolar bone, but no horizontal bone loss was observed. MARPE doesn't cause alveolar bone defects. MARPE can preferred for expansion in late adolescents and young adults. Keywords: cone beam computed tomography, MARPE, skeletal expansion