CHRONIC CATARRHAL GINGIVITIS IN PATIENTS DURING CLEAR ALIGNER THERAPY: PREVALENCE, DYNAMICS, AND CLINICAL ASSOCIATIONS
DOI:
https://doi.org/10.32782/2786-7684/2026-3-15Keywords:
clear aligners, chronic catarrhal gingivitis, periodontal status, OHI-S, API, PMA, BOP, orthodontic treatment, oral hygiene, preventionAbstract
Clear aligner therapy (CAT) is traditionally regarded as less traumatic to periodontal tissues than fixed appliances, yet data on the actual incidence of gingival inflammatory disease in this patient group remain limited. Objective. To evaluate the prevalence, incidence, and dynamics of chronic catarrhal gingivitis during 12 months of clear aligner therapy and to characterize the concurrent dynamics of oral hygiene status. Materials and Methods. A prospective single-center observational study included 60 patients aged 16–25 years, examined at baseline (T0), 6 months (T2), and 12 months (T3). Oral hygiene and periodontal status were assessed using OHI-S, API, PMA, and BOP; chronic catarrhal gingivitis was diagnosed clinically. Gingivitis prevalence was analyzed using a Cochran-Armitage trend test, Wilson score 95% confidence intervals, and Cohen’s h effect size; pairwise comparisons between adjacent time points were assessed using several effect measures (a two-proportion z-test, odds ratio [OR], and relative risk [RR]) and a Bayesian sensitivity analysis with a Jeffreys prior. Results. No gingivitis was recorded at baseline. Chronic catarrhal gingivitis was diagnosed in 14 patients (23.3%; 95% Wilson CI 14.4–35.4%) at 6 months and 19 patients (31.7%; 95% CI 21.3–44.2%) at 12 months. The Cochran-Armitage trend test confirmed a statistically significant increase in gingivitis prevalence over the observation period (Z=4.48, p<0.001; Cohen’s h=1.20). The increase between 6 and 12 months alone did not reach significance (z=1.02, p=0.31; OR=1.52, 95% CI 0.68–3.42; RR=1.36, 95% CI 0.75–2.45; Cohen’s h=0.19), a conclusion consistently supported by all four methods and by Bayesian posterior estimates (23.8% and 32.0%, respectively). Gingivitis development paralleled a statistically significant deterioration in OHI-S, API, PMA, and BOP (p<0.001 for all). Conclusions. Clear aligner therapy is associated with a statistically significant increase in the prevalence of chronic catarrhal gingivitis during the first 6 months of treatment, followed by a stabilization of the incidence rate. These findings support the need for intensified periodontal monitoring specifically during the early treatment phase
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