The chronology of the radiographic visibility of the periodontal ligament and the root pulp in the lower third molars.

Eruption and mineralization of third molars are the main criteria for dental age estimation in living adolescents. As the validation of completion of the 18th year of life appears not to be possible with the forensically necessary probability even if all the third molars of a person are completely mineralized, degenerative dental characteristics might be used for this purpose. In previous publications by Olze et al. (2010a,b) the radiographic visibility of the periodontal ligament and the root pulp in lower third molars were suggested as methods for this purpose. The aim of this study was to validate these characteristics in a large study population with a wide age range. In a material of 2346 orthopantomograms of 1167 female and 1179 male Germans aged from 15 to 70years the radiographic visibility of the root pulp in the lower third molars with completed mineralization were studied according to stage classifications proposed by Olze et al. (2010a,b). 1541 orthopantomograms of 705 females and 836 males with a sufficient quality of the radiograph showed at least one third molar. The suitability of the studied characteristics for age estimation in living individuals could be confirmed. Males and females presenting stage 1 of both characteristics were older than 18years of life. Males and females presenting stage 2 of both characteristics were older than 21years of life. The high number of missing third molars in the studied age group (46-60%) must be considered as a limitation of the methods. In further studies the influence of ethnicity, dietary habits and modern dental health care on the characteristics in question should be investigated.