Chronological age estimation base on third molar development from panoramic radiograph in Thai population

The purpose of this study was to assess the chronological age based on the developmental stages of third molars in thai population by using demirjian's classification system. the sample consisted of 1,729 digital panoramic radiographs from thai subjects aged between 9.26 and 25 years. statistical measures were calculated at stages a - h in males and females for both impacted and non - impacted third molars. the present study showed that females reached the completion root formation earlier than males both maxillary and mandibular third molars. at the age 18 years,for maxillary third molars,formation of the inter-radicular bifurcation has begun (stage e). however,at the same age for mandibular third molars,stage e was only found females,whereas stage f (root length is at least as great as crown length and have funnel-shaped endings)was found in males. the determined probability of thai individual being younger or older than 18 years for legislation might be valuable in future forensic practice.