Palatal changes in crossbite patients treated with rapid maxillary expansion versus untreated ones: A geometric morphometric study

OBJECTIVE: The present study aimed to analyze palatal changes due to rapid maxillary expansion (RME) by using modern geometric morphometric analysis (GMA) on 3D models. SETTINGS AND SAMPLE POPULATION: Forty children with posterior crossbite and maxillary deficiency were selected for this study. Twenty children were treated with RME (mean age 7.4 ± 0.8 years), whereas 20 children were not treated (mean age 7.2 ± 1.1 years). MATERIALS AND METHODS: In the treated group, RME screw was activated until overcorrection was achieved and the RME appliance remained in place for 11 months. Digital dental casts were recorded before treatment and 1 year after the end of active treatment. GMA was performed to compare shape and dimensional variations among groups (between-group principal component analysis). RESULTS: All children in the treated group achieved crossbite correction. None of the control group children achieved crossbite self-correction. No significant shape and dimensional changes were noted in the control group after 1 year. On the other hand, significant shape and dimensional changes were noted in the treated group after 1 year (p<0.05). Most of the shape changes in the treated group were similar but more pronounced compared to those observed in the control group. All major changes in palatal morphology occurred on the lateral sides of the palatal vault (widening) and at the height (shortening). Some shape changes were observed in the treated group alone. CONCLUSIONS: Application of GMA to evaluate the effects of RME in crossbite patients revealed significant changes in palatal morphology compared with the absence of changes in the control group.