Symmetry of carious lesions in primary and permanent teeth in children as a predictor of future caries patterns.

This study evaluated the bilateral symmetry of carious lesions in the primary and permanent teeth of children. The clinical records of patients aged 3 to 14 years who had carious lesions were evaluated. Dental caries was assessed using the modified decayed, missing, and filled teeth (dmft/DMFT) index, and the biofilm was assessed using the O'Leary plaque control record. The results were analyzed considering the presence or absence of caries and the stages of caries. The kappa coefficient between the left and right sides was calculated, and the chi-square test was applied (P < 0.05). The sample consisted of 206 children and 4802 teeth (2127 primary and 2675 permanent teeth). Fifty-one percent of the sample was female, and the mean age was 8.28 (SD 1.62) years. The mean number of dmft/DMFT was 4.45 (SD 3.61), and the mean O'Leary plaque index was 27.38%. The overall symmetry for the presence/absence of dental caries was 49.5% (n = 342), and the symmetry for the stage of caries was 43.5% (n = 301). The symmetry was similar in primary and permanent teeth for the presence/absence of caries (50.83% and 47.39%, respectively) and stages of caries (42.08% and 45.89%, respectively). Among the teeth that showed symmetry of carious lesions, there was an association between the hygiene condition and the presence of lesions in all maxillary and mandibular primary second molars and in the mandibular permanent right first molar (P < 0.05). A bilateral symmetric relationship of carious lesions was observed in the primary canines, primary first and second molars, permanent central and lateral incisors, first premolars, and permanent first molars in both the maxillary and mandibular arches. The results suggest that the presence of a carious lesion on a tooth surface can predict vulnerability to caries on the contralateral tooth, allowing the dentist to pursue targeted preventive action.