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Objectives We present a new distance‐based exponential regression approach based on published histological data to refine the objectivity, accuracy, and precision of age estimates of LEH defect formation on the anterior dentition. Methods Published histological data of anterior tooth crown growth for two samples (northern European and southern African) were fitted with exponential trendlines to construct exponential regression equations for each tooth type. A theoretical comparison of the age estimates produced by two commonly used methods (decile chart and linear regression), and those based on the exponential regression equations presented in this article were undertaken. Paired‐samples t‐tests were used to determine whether the estimates obtained by these methods differed significantly. Results Exponential regression equations were able to accurately replicate age estimates produced by the decile‐chart method. For defects that fell precisely on a decile, estimates differed by 1–23 days. Estimates based on the linear regression method were consistently younger by 4.5–16 months. For defects that fell within deciles, the exponential regression equation estimates, when different, were 12 days to 4 months older than those yielded by the decile method. Conclusions By combining currently published histological data on anterior tooth crown growth with a regression approach, it is possible to produce more accurate age estimates than yielded by methods that do not rely on histological data. Furthermore, this approach also greatly improves the objectivity, precision and replicability of results, especially for defects that fall between deciles, when compared to the decile chart method.

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Retinoblastoma in children, experience at a pediatric hospitalMethods: Retrospective analysis of clinical charts of 41 children (59 eyes) diagnosed with retinoblastoma and treated by a multidisciplinary team at Hospital Luis Calvo Mackenna in Santiago-Chile, between 1999 and 2007. The information included gender, laterality, diagnosis age, presenting signs, tumor spread, treatment modality and survival rate. Results: A total of 23 cases (56%) were unilateral and 18 cases (44%) were bilateral. The mean age at diagnosis was 21.6 months (range 2 -84) and 27 children (65.9%) were male. The most common presenting signs were leucokoria (51.2%), strabismus (24.4%) and proptosis (4.9%). Enucleation was performed in 48 eyes (81.3%), being the only required treatment in 17 children (41.5%). The remaining 24 patients received systemic and/or local therapy with chemotherapy, focal therapy and external beam radiation. 5 children died during the follow -up study period, due to extraocular extension to the orbit, central nervous system and bone marrow. Conclusion: In spite of high enucleation rate as initial therapy for retinoblastoma, the survival rate with this current treatment protocol is similar to those from developed countries.