Age-Dependent Root Apex Closure in Primary Second Molars

Background: Primary teeth play a crucial role in guiding permanent dentition; however, data regarding root apex closure in primary molars remain limited. The aim of this study was to evaluate the age-related root apex closure status of primary second molars in children aged 2–7 years using panoramic radiographs and to obtain clinically guiding data for pediatric dental treatment planning. Materials and Methods: This cross-sectional, descriptive, and retrospective study evaluated panoramic radiographs. A total of 1628 panoramic radiographs obtained from 1628 patients were evaluated, each representing one individual with primary second molars. The relationships between age groups, gender, and root apex closure status were analyzed statistically with a significance level set at p < 0.05. Results: No root apex closure was observed in either maxillary or mandibular primary second molars in the 2–2.99-year age group. In the 3–3.99-year group, a limited number of closed apices were detected only in mandibular primary second molars. A marked increase in the proportion of closed apices was observed in both jaws in the 4–4.99-year group. In the 5–5.99- and 6–6.99-year groups, root apex closure was completed in the majority of maxillary and mandibular primary second molars. Although statistically significant gender-related differences were detected in certain age groups, these differences were not consistent across all age categories. Conclusions: Root apex closure in primary second molars demonstrates a clear age-dependent pattern between 2 and 7 years of age. The findings are expected to provide clinically relevant guidance for pediatric endodontic treatment planning and contribute to the limited literature regarding root development in primary teeth.