Root Pulp Visibility as a mandibular maturity marker at the 18-year threshold in the Maltese population

Introduction: The determination of age of majority (the 18-year-old threshold) using the popular Demirjian tooth staging method is unreliable, so other maturity markers are required. This study examines whether the Root Pulp Visibility (RPV) of the mandibular third molar is a useful indicator of age. Methods: One thousand six dental panoramic radiographs (DPTs) were examined and the left mandibular third molar assessed according to the RPV stages using the method of Olze et al. (Int J Legal Med 124:183–186, 2010) as modified by Lucas et al. (Forensic Sci Int 270:98–102, 2017). Six hundred sixty-two DPTs, 288 males and 374 females, satisfied the inclusion criteria. Results: Individuals who had reached stages RPV-A and RPV-B were represented in a wide range of ages spanning the 18-year-old threshold. Individuals who had reached stages RPV-C and RPV-D were all above the 18-year-old threshold. It was not possible to analyse a large number of DPTs for various reasons. Discussion: Individuals whose mandibular third molar exhibited stages RPV-C and RPV-D may be deemed to have reached the age of majority. These results are consistent with other published studies. Variation in the rate of development of the third molar limits the applicability of this method. Conclusions: RPV staging is an accurate method of determining the 18-year-old threshold. Substitute methods are required in a large number of cases.