Dentoskeletal changes and their correlations after micro-implant-assisted palatal expansion (MARPE) in adults with advanced midpalatal suture ossification

Objectives To evaluate and correlate the dentoskeletal changes of adult patients after miniscrew-assisted rapid palatal expander (MARPE) in the two final stages of midpalatal suture ossification. Materials and methods This interventional pre-post clinical study consisted of 20 adults (24.9 +/- 1.8 years), with transverse maxillary atresia, divided into two subgroups (n=10) based on the ossification degree of the midpalatal suture: stage D, fusion completed in the palatine bone; and stage E, fusion anteriorly in the maxilla. Cone beam computed tomography (CBCT) in the pre- (T-0) and post-treatment (T-1) time intervals were used to evaluate the anterior and posterior sutural opening, activation of the expander screw, vestibular-lingual inclinations, and widths of first premolars and first molars. Maxillary interincisor diastema was measured on patients' plaster models in the same timepoints. The Wilcoxon-Mann-Whitney test, generalized linear models (GLM), and chi-square (chi(2)) test were employed. Results All variables significantly increased after MARPE therapy regardless of the ossification degree (P<0.05). Patients with stage D suture presented wider interincisal diastema and maxillary suture opening (on both regions, anterior and posterior) when compared with patients with stage E (P<0.05). Maxillary interincisor diastema was positively associated with anterior and posterior suture opening for all subjects (P<0.05). MARPE therapy was unsuccessful in six patients, mostly presented by individuals with E maturation stage of the midpalatal suture. Conclusions After MARPE, a significant correction in the transverse defect of the maxillary basal bone was achieved for adults in the last two midpalatal suture maturation stages.

Automated summary

The MARPE therapy significantly corrected the transverse defect of the maxillary basal bone in adult patients, regardless of the ossification degree of the midpalatal suture. Patients in stage D had wider interincisal diastema and suture opening compared to stage E patients.