Comparison of methods for estimating the timing of linear enamel hypoplasia formation: Clinical validation against a known systemicevent

Background/purpose: Linear enamel hypoplasia (LEH) provides a permanent record of developmental disturbances during amelogenesis. This study compared four LEH age estimation methods against a documented systemic event. Materials and methods: A 12-year-old Taiwanese girl with visible LEH on her maxillary central incisor had experienced a febrile convulsion at 1 year 7 months of age (1.58 years). Crown height (10.5 mm) and LEH distance from incisal edge (4.0 mm) were measured. Four methods were applied: chart method, Goodman and Rose regression equation, and Reid and Dean models (Northern European and Southern African). Results: The Goodman and Rose regression method (1.55 years) demonstrated highest accuracy with only 1.9 % deviation from actual timing. The chart method (2.5-3.0 years) and Reid and Dean models (2.7-3.1 years) overestimated by 58-96 %. Conclusion: The Goodman and Rose regression method provided superior accuracy for estimating LEH formation timing. Appropriate method selection is crucial for accurate age estimation in pediatric dental practice.