One of the most widely used methods of forensic age estimation via dentition was derived in 1973 by Demirjian, Goldstein, and Tanner.
[1] Commonly referred to as "Demirjian's Technique," the changes from initial calcium deposition to complete apex are divided into eight observable stages. Each stage is further characterized by up to three additional qualifying criteria (a,b,c). If only criterion (a) is listed, then it must be met. If (a) and (b) are listed, then at least (a) must be satisfied. If (a), (b), and (c) are listed, then both (a) and (b) must be met. Additionally, "at each stage . . . the criteria for the
previous stage must be satisfied"
[ibid]. The technique is applied to 7 observed teeth, with the individual "score" from each tooth being added. The resulting sum is then referenced on a corresponding conversion chart with ages ranging from 3 to 17 years, in increments of one-tenth.
Though the Demirjian method worked well with the original French Canadian subject sample, more recent studies have questioned its effectiveness when applied to sample groups of varied descent. A 2007 study by Tunc and Koyuturk revealed that the technique was less accurate with regard to sampled Turkish children, who displayed more advanced dental maturity.[2]
A 2001 article using Belgian children as the sample group confirmed popular findings that the Demirjian method has a tendency to result in over-estimation of age, but employed new adaptations to the scoring system to achieve an increase in accuracy.[3]
The Demirjian technique remains a well-regarded forensic tool for determining age in sub-adults. As with all estimation methods, there is a discernible margin of error, but overall the technique still provides advantages over other dentition methods, especially those based on tooth eruption, which can be highly influenced by health and environmental factors. It should be remembered that in practical application, a synthesis of various age-estimation methods generally yields the best overall results.
1. Demirjian, A., et al. A New System of Dental Age Assessment. Human Biology 45(2): 211. 1973.
