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Updated: Sep 4, 2025

Systematic Assessment of Mammalian Skull Specimens for Dental and Temporomandibular Joint Pathology
Published on: August 22, 2022
Root canal width as a mandibular maturity marker at the 18-year threshold in the Maltese population
Sriwisut Tangkabutra1, Emad Alzoubi1, Graham Roberts2
1Department of Child Dental Health and Orthodontics, Faculty of Dental Surgery, Medical School, University of Malta, Msida, Malta.
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 ratio of the root canal widths (RCW) of the mandibular first, second and third molars is a useful indicator of age.
Methods:
Nine hundred eighteen dental panoramic radiographs (DPT) were examined and the ratio of the mid-points of the distal roots of the left mandibular first, second and third molars assessed according to the RCW stages as described by Roberts (J Forensic Sci 62:351-354, 2017).
Results:
Individuals who had reached stages RCW-A and RCW-B were represented in a wide range of ages spanning the 18-year-old threshold. Individuals who had reached Stage RCW-C were all above the 18-year-old threshold. It was not possible to analyse a large number of DPTs for various reasons.
Discussion:
Individuals categorised as stage RCW-C may be deemed to have reached the 18-year-old threshold. These results are consistent with other published studies. Variation in root morphology and in the rate of development of the third molar limits the applicability of this method.
Conclusions:
RCW staging is an accurate method of determining the 18-year-old threshold. Its limited applicability requires the use of substitute markers in a large number of cases.

