The Relationship Between Orthodontic Malocclusion Severity and Periodontal Clinical and Biochemical Parameters in Adolescents: A Cross-Sectional Study.

Background: This study aims to investigate the relationship between malocclusion severity and periodontal clinical parameters and periodontal disease-related biochemical markers in adolescents. Materials and Methods: The study's registration number is NCT07127744. It included 88 individuals aged 12-17 years. Participants were divided into 4 different groups (n = 22) with equal distribution in each group according to the Dental Aesthetic Index (DAI). Clinical (PI, GI, BOP, PPD) and biochemical (RANKL, OPG, RANKL/OPG, TOS, TAS, OSI in gingival crevicular fluid) measurements were performed. Sociodemographic data (age, gender, education, BMI) were recorded. The relationship of all parameters with DAI and with each other was statistically analyzed. Multiple comparison tests, correlation analysis, and multiple linear regression analysis were applied. Statistical significance was accepted at p < 0.05. Results: Significant differences were found between minor and very severe malocclusion in all clinical periodontal and biochemical parameters (except TAS) (p < 0.05). With increasing education level, a decrease in BOP (p = 0.041) and a significant increase in OPG (p = 0.003) were observed. A strong positive correlation was found between DAI and TOS and RANKL; and a moderate correlation was found with periodontal parameters except PI. Multivariate general linear model analysis revealed that DAI score was significantly associated with all clinical and biochemical parameters (Pillai's Trace = 0.652, p < 0.001). The largest effect sizes were observed for TOS (partial η2 = 0.455), RANKL (partial η2 = 0.402), and PI (partial η2 = 0.300). Conclusions: There is a significant association between increased malocclusion severity and periodontal disease-related parameters. TOS and RANKL may be sensitive biomarkers of malocclusion-related periodontal tissue destruction.