An assessment of the versatility of Kvaal's method of adult dental age estimation in Indians

Objectives: Radiographic dental age estimation methods are viable in the living and deceased. One such method [Kvaal et al. Forensic Sci Int 1995;74:175-85] quantified secondary dentinal deposition indirectly through measurements of tooth and pulp lengths and widths. The method is untested on non-European populations and our objective was to assess its accuracy in Indians and determine if population-specific formulae improved age estimation. Methods: Digital radiographs of 100 Indians were made using the conventional paralleling technique (n = 47) and bisecting angle technique (n = 53), the latter being the prevalent method of periapical radiography in India. Pulp and tooth lengths and widths were measured (using commercially available computer software) and their ratios substituted in Kvaal's formulae; also, population-specific formulae were developed by us using principal component regression analyses. Results: The average errors of age estimation were similar to +/- 18-20 years for the paralleling and similar to +/- 19-21 years for the bisecting angle technique; estimates in both samples of radiographs were significantly different from actual age (p <0.001). The Indian formulae produced smaller errors for both samples (similar to +/- 11-14 years), an improvement over Kvaal's formulae. Conclusions: Large errors from Kvaal's formulae may owe primarily to variation in the rate of secondary dentinal deposition in Indians influenced both by environmental and genetic variation. Errors using the Indian formulae, whilst smaller, are more than in the original study and other European samples, implying large errors in age estimates in Indians irrespective of population-specific formulae. This may preclude the method's routine usage in estimating age in adult Indians. (C) 2011 Elsevier Ltd. All rights reserved.