Changes in skeletal and dental relationship in Class II Division I malocclusion after rapid maxillary expansion: a prospective study.

Carolina Baratieri,Matilde C G Nojima,Lincoln I Nojima,Matheus Alves Jr,Ana Maria Bolognese

doi:10.1590/2176-9451.19.3.075-081.oar

Abstract

ObjectiveTo assess skeletal and dental changes immediately after rapid maxillary expansion (RME) in Class II Division 1 malocclusion patients and after a retention period, using cone beam computed tomography (CBCT) imaging.MethodsSeventeen children with Class II, Division 1 malocclusion and maxillary skeletal transverse deficiency underwent RME following the Haas protocol. CBCT were taken before treatment (T1), at the end of the active expansion phase (T2) and after a retention period of 6 months (T3). The scanned images were measured anteroposteriorly (SNA, SNB, ANB, overjet and MR) and vertically (N-ANS, ANS-Me, N-Me and overbite).ResultsSignificant differences were identified immediately after RME as the maxilla moved forward, the mandible moved downward, overjet increased and overbite decreased. During the retention period, the maxilla relapsed backwards and the mandible was displaced forward, leaving patients with an overall increase in anterior facial height.ConclusionRME treatment allowed more anterior than inferior positioning of the mandible during the retention period, thus significantly improving Class II dental relationship in 75% of the patients evaluated.

Highlights

Intraexaminer reliability values were determined by means of intraclass correlation coefficient (ICC), with 95% confidence interval
Separation of the mid-palatal suture was clinically confirmed in all patients with increased opening of inter-incisor diastema or within 3-5 days following expander activation
These data were confirmed on the cone beam computed tomography (CBCT) image at T2

Summary

Objective

To assess skeletal and dental changes immediately after rapid maxillary expansion (RME) in Class II Division 1 malocclusion patients and after a retention period, using cone beam computed tomography (CBCT) imaging. Methods: Seventeen children with Class II, Division 1 malocclusion and maxillary skeletal transverse deficiency underwent RME following the Haas protocol. Changes in skeletal and dental relationship in Class II Division I malocclusion after rapid maxillary expansion: a prospective study. The aim of this study is to use CBCT imaging to assess changes in dental and skeletal relationships in Class II, Division 1 malocclusion patients immediately after RME as well as after a 6-month retention period. Afterwards, the expander screw was stabilized with a 0.012-in double thread ligature and was passively kept in place for the following six months after which the appliance was removed

MATERIAL AND METHODS

RESULTS

DISCUSSION

CONCLUSIONS