Interceptive maxillary expansion in children in the early mixed dentition with maxillary anterior crowding

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ABSTRACT

Aim

The objective of this study was to assess whether maxillary expansion in the early mixed dentition in cases exhibiting anterior crowding leads to the spontaneous correction of anterior crowding.

Methods

Thirty-seven patients were included in this retrospective cohort study. The included patients had anterior crowding of ≥ 4 mm between the upper deciduous canines or Little’s index of ≥ 3 mm. All patients were treated in the early mixed dentition with RME. Pre- and post-treatment study casts were analyzed. The PAR score was assessed.

Results

The mean anterior crowding of the upper jaw was -3.57 mm (SD = 2.39). After expansion, the mean available space was 0.11 mm (SD = 2.24), a statistically significant difference (p < 0.001). The mean crowding in the lower jaw was -2.39 mm (SD = 2.59) before expansion and -1.48 mm (SD = 1.96) after expansion. The difference was statistically significant (p = 0.016). The mean weighted PAR-score before expansion was 21.39 (SD = 8.54), and after expansion, it was 16.78 (SD = 8.19). This represented a decrease of 4.61 (21.6%), which was statistically significant (p = 0.0045).

Conclusion

Treatment limited to RME in the early mixed dentition significantly reduced crowding in the maxillary arch. The weighted PAR exhibited a significant decrease of 21.6%; however, this does not constitute an “improvement” according to the PAR, which mandates a minimum reduction of 30 percent.

Statistics and Study Design

The Wilcoxon Signed Ranks Test was used to assess whether there were significant differences. Multiple comparisons were addressed using the Benjamini-Hochberg post-hoc analysis. A P-value below 0.05 was considered statistically significant.
Retrospective cohort study.

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