Reliability of age estimation using Demirjian's 8 teeth method and India specific formula

The estimation of the age of a person has been an archaic exercise, and since decades even dentists have contributed to this science with several methods through radiography. The tooth with its developmental stages provides us with a non-invasive modality to determine the age of the person.

To evaluate the reliability of age estimation using Demirjian's 8 teeth method following the French maturity scores and India specific formula.

The study was conducted on 121 archived digital orthopantamographs which were predominantly pre-treatment orthodontic radiographs from patients without any obvious developmental anomalies. The radiographs were divided into two gender specific groups and further sub-divided into two smaller groups of 7-16 years and 16.1-23 years. The radiographs were evaluated as per Demirjian's criteria and age was calculated using the formula developed for the Indian population.

The results showed that the mean absolute error for the study sample was 1.18 years; in 57.9% of cases the error rate was within ±1 year. The mean absolute error in males (7-16 years) was 1.2 years; in males (16.1-23 years) was 1.3 years; in females (7-16 years) was 0.95 years and in females (16.1-23 years) was 1.16 years.

The age estimation using this method narrows down the error rate to just over one year making this method reliable. However the inclusion of third molar increases the error rates in the older individuals within the sample.