Clinical Outcomes of Rapid Maxillary Expansion in Mixed Dentition Patients: A Prospective Clinical Study

Abstract

Background

Rapid maxillary expansion (RME) is a well-established orthopedic procedure for correcting transverse maxillary deficiency and posterior crossbite during the mixed dentition period. In addition to increasing maxillary width, RME has been reported to improve arch dimensions, occlusal relationships, and overall dental alignment while providing stable treatment outcomes.

Aim:

To evaluate the clinical outcomes of RME in children during the mixed dentition period by assessing changes in maxillary arch dimensions, occlusal parameters, treatment stability, correction of posterior crossbite, dental midline improvement, patient compliance, complications, and overall treatment outcomes.

Materials and Methods:

A prospective clinical study was conducted on 30 children aged 7–12 years presenting with transverse maxillary deficiency requiring RME. Clinical measurements including intercanine width, intermolar width, maxillary arch perimeter, maxillary arch length, palatal width, overjet, and overbite were recorded at baseline, immediately after expansion, and at the 6-month follow-up. Posterior crossbite correction, dental midline improvement, patient compliance, treatment-related complications, and overall treatment outcomes were also evaluated. Data were analyzed using repeated measures analysis of variance (ANOVA) with Bonferroni post hoc comparisons. Statistical significance was set at P < 0.05.

Results:

The mean age of the participants was 9.54 ± 1.42 years, with 53.3% males and 46.7% females. Significant increases were observed in intercanine width (28.42 ± 2.31 mm to 33.48 ± 2.39 mm), intermolar width (42.16 ± 2.85 mm to 48.31 ± 2.87 mm), maxillary arch perimeter (71.62 ± 3.84 mm to 75.41 ± 3.69 mm), maxillary arch length (33.85 ± 2.11 mm to 35.12 ± 2.04 mm), and palatal width (27.81 ± 1.96 mm to 32.65 ± 2.01 mm) at the 6-month follow-up (P < 0.001 for most parameters). Significant reductions were observed in overjet (3.84 ± 0.89 mm to 3.12 ± 0.81 mm; P = 0.009) and overbite (3.41 ± 0.92 mm to 2.93 ± 0.81 mm; P = 0.022). No significant relapse was detected between post-expansion and the 6-month follow-up for any parameter. Complete posterior crossbite correction was achieved in 90.0% of participants, while dental midline improvement was observed in 80.0%. Excellent patient compliance was reported in 76.7% of subjects. Sixty percent of participants experienced no treatment-related complications, and 66.7% demonstrated excellent overall treatment outcomes.

Conclusion:

RME performed during the mixed dentition period resulted in significant and stable improvements in transverse maxillary dimensions, arch morphology, and occlusal relationships with minimal complications and excellent patient compliance. The findings support RME as an effective and predictable treatment modality for managing transverse maxillary deficiency in growing children.