Chronology and sequence of permanent tooth eruption in childrenin Buenos Aires City

Abstract

Knowledge of the timing and sequence of permanent tooth eruption is essential for assessing occlusal development and providing population-specific reference standards to support diagnosis, prevention, and treatment planning. Aim: To estimate mean age for eruption of permanent teeth, except third molars, in children in Buenos Aires City (CABA), compare means according to sex, jaw and laterality, and identify the eruption sequence per arch. Materials and Method: An observational, prospective, cross-sectional study was conducted (March–July 2024) on 4- to 15-year-old children who received care at Buenos Aires University’s School of Dentistry and at four private offices in Buenos Aires City. A tooth was considered erupted when at least one cusp or incisal edge pierced the gingival epithelium. Mean ages were estimated using the Kärber method with 95 % confidence intervals (CI), and the sequence was established by placing those means in order. Results: We evaluated 1,063 children (532 female), mean age 9.9 ± 2.6 years. The first teeth to erupt were lower central incisors, and the last were upper second molars. No difference was observed between hemiarches. Teeth belonging to the lower incisor-canine group erupted significantly earlier than their homologous upper teeth. Girls presented earlier eruption than boys, with significant differences for all teeth except upper central incisors, and upper and lower first molars. Sequence for the upper jaw was 6–1–2–4–3–5–7 in girls, and 6–1–2–4– 5–3–7 in boys. Sequence in the mandible was 1–6–2–3–4–5–7 in girls, and 1–6–2–4–3–5–7 in boys, with chronological proximity between canine and premolars in some comparisons. Conclusion: In this sample, eruption began with lower central incisors, was symmetrical, earlier in girls, and earlier in the lower incisor-canine group, with sequential stability in both sexes during the first transitional period, and variations in the second.