Global variations in eruption chronology of primary teeth: A systematic review and meta-analysis

This systematic review aimed to assess global variations in the eruption chronology of primary teeth in children and the role of sexes, jaws, and socio-economic status on eruption timing. An extensive search of electronic databases, grey literature, and hand-searching was carried out until April 2023 A total of 42,109 children, with an age range of 0–83 months were included from 42 studies (22 in Asia, 7 in Europe, 5 in Africa, 4 in North America, 3 in Oceania and 1 in South America). The mandibular central incisor was the first tooth to erupt at 6 months in North America and 13.5 months in Asia while the mandibular second molar erupted at 20.1 months in Europe and 29 months in South America. The age of primary teeth eruption was advanced in the European population followed by North America, Africa, Oceania, and Asia while it was delayed in the South American population. Meta-analysis showed that tooth eruption was earlier in the left quadrant than the right but the role of other factors (sexes, jaws, and socio-economic status) was insignificant. Population-specific data on primary teeth emergence may serve as a baseline for future research. In clinical practice, these population-based eruption charts can serve as a valuable asset for diagnosis and treatment planning in children. •Primary teeth eruption is advanced in the Europeans and delayed in the South American population.•The eruption timing of primary teeth is earlier in the left quadrant than the right.•The role of sexes, jaws and socio-economic status on tooth eruption is insignificant.•Population-specific data on primary teeth emergence may serve as a baseline for future research.