The effect of Ekman–Westborg and Julin trait (generalized megadontia) and localized megadontia on tooth components size and ion content

Aims: The objective of this study is to compare size, enamel thickness and ion relative concentration in generalized megadontia (Ekman- Westborg and Julin trait) and a localized megadont upper third molar to normal teeth. Materials and methods: The MD dimensions of permanent teeth were compared to controls. Tooth components of molars were measured from X-rays and compared to controls. The enamel and dentin relative amounts of elements of mandibular first permanent molar and deciduous canines of E-WJ trait girl, and megadont upper third molar were determined using ESD program of SEM and compared to match-paired normal teeth. Results: The teeth of the girl diagnosed with E-WJ trait were true megadont (larger than mean ± 2SD). The ratio of enamel thickness to M-D dimension of molars of E-WJ trait and localized megadontia molars is reduced in comparison with normal similar teeth. In the enamel, carbon and silica concentrations were different in E-WJ trait teeth. Conclusions: The enamel thickness was reduced in the E-WJ trait and megadont molars, but the relative amount of elements in enamel and dentin was similar to normal. The megadontia is due to a very large tooth germ, as determined by the DEJ, while the ratio of enamel apposition from the total M-D dimension is reduced. Clinical relevance: Generalized megadontia, as observed in E-WJ trait, is due to large tooth germ, but the enamel thickness is similar to normal. Extractions of permanent teeth are necessary in order to allow normal eruption of teeth.