Skeletal, Dentoalveolar, and Periodontal Changes of Skeletally Matured Patients with Maxillary Deficiency Treated with Microimplant-assisted Rapid Palatal Expansion Appliances: A Pilot Study

Microimplant-assisted rapid palatal expansion (MARPE) has recently been offered to adult patients for correcting maxillary transverse deficiency. However, there is limited information in the literature on the success of this appliance and its skeletal and dental effects on skeletally matured patients. The purpose of this study was to investigate the immediate skeletal, dentoalveolar, and periodontal response to MARPE appliance using cone-beam computed tomography in a skeletally matured patient as assessed by the cervical vertebral maturation method. Materials and Methods: Eight consecutively treated patients (2 females, 6 males; mean age of 21.9 ± 1.5 years) treated with a maxillary skeletal expander were included in the study. Measurements were taken before and after expansion to determine the amount of midpalatal suture opening, upper facial bony expansion, alveolar bone bending, dental tipping, and buccal bone thickness (BBT). Data were analyzed using a one-way ANOVA and matched-pair t-test (α = 0.05). Results: Midpalatal suture separation was found in 100% of the patients with no dislodged microimplants. Total maxillary expansion was attributed to 41% skeletal, 12% alveolar bone bending, and 48% dental tipping. Pattern of midpalatal suture opening was found to be parallel in both the coronal and axial planes. On average, the absolute dental tipping ranged from 4.17° to 4.96° and the BBT was reduced by an average of 39% measured at the premolars and molars. Conclusions: The MARPE appliance can be a clinically acceptable, nonsurgical treatment option for correcting mild to moderate maxillary transverse discrepancies for skeletally matured adult patients with a healthy periodontium.