Rapid maxillary expansion related sutural and dentoalveolar changes provoke early-term oxidative stress

Background: The management of oxidative stress-related cellular activity plays an important role in the bone healing process and dentoalveolar resorption. The aim of this study was to investigate the effects of rapid maxillary expansion on local and systemic oxidative stress levels. Methods: Thirty-five volunteer patients (17 females and 18 males) who needed rapid maxillary expansion were included in the study. Serum and unstimulated saliva samples were collected from each patient during four different periods: a week before the treatment (T0), the first day when sutural opening was detected clinically and radiographically (T1), the last day of the active expansion period (T2), and after the completion of a 3-month retention period (T3). To evaluate the patients’ periodontal status, plaque index, gingival index and probing pocket depth scores were recorded for each period. 8-hydroxydeoxyguanosine (8-OHdG), total oxidative status (TOS), total antioxidant status (TAS) and oxidative stress index (TOS/TAS: OSI) biomarkers were evaluated with ELISA and spectrophotometric methods to determine the local and systemic oxidative stress levels. Results: There were no statistically significant differences in the clinical periodontal parameters between the four measurement periods (p > 0.05). In the T1 period, only the salivary levels of the 8-OHdG (T1-T0; p:0.001, T2-T1; p:0.030, T3-T1; p:0.045), TOS (T1-T0; p < 0.001, T2-T1; p < 0.001, T3-T1; p < 0.001) and OSI (T1-T0; p < 0.001, T3-T1; p < 0.001) were statistically significantly higher when compared to the other periods. On the other hand, both the serum and salivary TAS levels there were not statistically significantly different between the periods (p > 0.05). Conclusion: Periodontal and skeletal changes associated with rapid maxillary expansion cause an increase in only salivary oxidative stress levels, especially during the initial sutural opening period (5–7 days). Trial registration: Clinical Trial Number is NCT06937775. It was recorded retrospectively (Record date 21/04/25).