Age of linear enamel hypoplasia formation based on Massler and colleagues' and Reid and Dean's standards in a Polish sample dated to 13th-18th century CE.

In the study of enamel hypoplasia formation ages basically two standards of dental development are being applied. According to some authors, different methods produce different results, thus it is critical to decide which method to use. This study focuses on the comparison of three methods for estimating ages of linear enamel hypoplasia (LEH) formation. The skeletal material derives from three burial grounds localized on the territory of Poland, dated to 13th-18th c. CE. In total 642 teeth of 77 individuals were qualified for the study. The position of LEHs on the crown surface was measured and then converted to age at formation using the regression equations proposed by Goodman and Rose, Goodman and Song, and the data provided by Reid and Dean. There were 51.9% of individuals and 17.9% of teeth affected by LEH. The lowest age estimates were provided by the Goodman and Rose's method then higher by the Goodman and Song's method and the highest using the Reid and Dean's data. The age ranges and peaks of LEH provided by the three methods differed more for the maxillary than for the mandibular teeth. Crown formation ages supplied by Reid and Dean account for intra- and inter-tooth as well as inter-population variation in the timing of tooth development and also for variation in crown heights. This approach undoubtedly increases reliability of the results. Thus, it seems advisable to use the Reid and Dean's standard when calculating ages of enamel hypoplasia formation.