Examination of tooth color changes in patients undergoing rapid palatal expansion

This study was conducted to examine the changes in tooth color caused by Bonded acrylic cap splints and Hyrax expansion appliances used in rapid maxillary expansion (RME) treatment and to compare these changes with a control group. A total of 60 individuals aged 8–15 years diagnosed with maxillary constriction were included in the study and divided into three groups: Bonded acrylic cap splint, Hyrax, and control group. Tooth color measurements were performed using a spectrophotometer at two time points, before (T₀) and after (T₁) HÜÇG treatment, using CIE L*, a*, and b* color parameters. Total color change was calculated using the ΔE value. Wilcoxon Signed Rank test was used for within-group comparisons, while Kruskal–Wallis test and Bonferroni corrected post hoc analyses were used for between-group comparisons. At baseline, no statistically significant differences were found among the groups in terms of L₀, a₀, and b₀ values. A significant decrease in L* values was observed in the Hyrax group between T₀ and T₁ (p <0.001), whereas no significant changes were detected in the Bonded acrylic cap splint and control groups. Regarding the a* parameter, significant changes were observed in the Bonded acrylic cap splint and control groups (p <0.05), while no significant change was found in the Hyrax group. For the b* parameter, statistically significant changes were detected in all groups between T₀ and T₁ (p <0.001). Intergroup comparisons of ΔE values revealed statistically significant differences among the groups (p <0.001). Mean ΔE values were higher in the Bonded acrylic cap splint and Hyrax groups compared with the control group; however, no statistically significant difference was found between the two expansion appliance groups. Nevertheless, ΔE values observed in both appliance groups were largely within clinically acceptable limits.(ΔE ≈ 3,3–3,7) In conclusion, rapid maxillary expansion with Bonded acrylic cap splint and Hyrax resulted in measurable but clinically limited changes in tooth color. These findings demonstrate that objective data can be provided in patient information.