Dental age assessment of young Iranian adults using third molars:
A multivariate regression study
Ali Bagherpour*, Najmeh Anbiaee , Parnia Partovi , Shayan Golestani , Shakiba Afzalinasab
* Oral & Maxillofacial Radiology, Dental Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences
Background: In recent years, a noticeable increase in forensic age estimations of living individuals has
been observed. Radiologic assessment of the mineralisation stage of third molars is of particular
importance, with regard to the relevant age group. To attain a referral database and regression equations
for dental age estimation of unaccompanied minors in an Iranian population was the goal of this study.
Moreover, determination was made concerning the probability of an individual being over the age of 18
in case of full third molar(s) development.
Materials and methods: Using the scoring system of Gleiser and Hunt, modified by Köhler, an investigation
of a cross-sectional sample of 1274 orthopantomograms of 885 females and 389 males aged
between 15 and 22 years was carried out. Using kappa statistics, intra-observer reliability was tested.
With Spearman correlation coefficient, correlation between the scores of all four wisdom teeth, was
evaluated. We also carried out the Wilcoxon signed-rank test on asymmetry and calculated the
Results: A strong intra-observer agreement was displayed by the kappa value. No significant difference
(p-value for upper and lower jaws were 0.07 and 0.59, respectively) was discovered by Wilcoxon signedrank
test for left and right asymmetry. The developmental stage of upper right and upper left third
molars yielded the greatest correlation coefficient. The probability of an individual being over the age of
18 is 95.6% for males and 100.0% for females in case four fully developed third molars are present. Taking
into consideration gender, location and number of wisdom teeth, regression formulae were arrived at.
Conclusion: Use of population-specific standards is recommended as a means of improving the accuracy
of forensic age estimates based on third molarsmineralisation. To obtain more exact regression formulae,
wider age range studies are recommended.
Journal of Forensic and Legal Medicine 19 (2012) 407e412