Investigation of bone remodeling in gingival crevicular fluid in patients treated with rapid maxillary expansion during pubertal period

Abstract

Purpose: We aimed to evaluate bone remodeling following 3-month and 6-month retention periods of rapid maxillary expansion (RME) in gingival crevicular fluid (GCF). Materials and Methods: 23 pubertal participants (15 girls- 8 boys, 12-15 years) with maxillary transversal deficiency were enrolled in the study. Following banded-type RME appliance was introduced into the mouth, RME protocol was initiated by turning the Hyrax screw twice daily (morning/evening) with ¼ activation. GCF samples were taken from right maxillary first molars at four different time points (T0: before the appliance was deployed, T1: following active phase, T2: at the end of the 3-month retention period, T3: at the end of the 6-month retention period) using paper strips. Probing depth, gingival index, plaque index, and bleeding percentage at probing were recorded. BALP, OPG, RANKL, and TNF-α levels were measured in GCF samples using ELISA kits. Results: Our study revealed that GCF's BALP and OPG levels remained unchanged over time in tension and pressure regions, and there were no statistically significant differences among regions at each time point (p>0.05). RANKL level was statistically significantly increased in the buccal region (the pressure region) at time T1 (p=0.042). The palatinal region's TNF-α level was statistically significantly higher than the buccal region at T0, T2, and T3 time points (p=0.005, p=0.042, and p=0.006, respectively). Our study showed no correlation between 3-month and 6-month retention periods and biomarkers indicating RME's bone metabolic activities. Conclusions: Further studies with different retention periods and larger sample sizes are suggested.