Changes of proximal caries during orthodontic treatment using intraoral scans with near-infrared imaging

Abstract

Background. Intraoral scanning using near-infrared imaging (NIRI) is a noninvasive method used to detect early caries. The authors quantified the prevalence and incidence of new proximal caries among orthodontic patients and evaluated the clinical factors associated with the severity of the caries. Methods. Serial full-mouth intraoral scans using NIRI were analyzed among 188 active orthodontic patients aged 10 through 73 years at their initial visit (T0) and after follow-up at least 6 months from initial visit (T1). Proximal caries was defined as distinct whitish lesions that are clearly distinguishable from the surrounding enamel detected through NIRI. The prevalence, pattern, incidence and severity of new proximal caries at T1 were evaluated. The association between severity and clinical factors, including age, preexisting proximal caries lesions detected via NIRI (NIRI+) at T0, evaluation period, and type of orthodontic appliances, was examined. Results. The prevalence of NIRI+ caries at T0 and T1 was 56.4% and 66.5%, respectively. NIRI+ lesions detected at least 6 months from initial visit (new NIRI+) were most frequently observed in the maxillary first molar (10.7%) followed by the first premolar (10.0%). The incidence of new NIRI+ caries was significantly higher in younger patients and in those with preexisting NIRI+ caries at T0 (P < .05). The severity of new NIRI+ caries was associated with younger age, preexisting NIRI+ caries, and longer evaluation interval (P < .05). Conclusions. Early caries was observed in approximately 46.8% of orthodontic patients during treatment. The incidence of new proximal caries was higher among young adolescents and those with preexisting caries. Practical Implications. Adolescents with preexisting caries and longer treatment durations, particularly those using conventional fixed appliances, warrant close monitoring due to the increased risk of developing multiple caries lesions.