Pulp tooth ratio in the estimation of age: A study on mandibular premolars

The aim of the study was to use Cameriere’s radiographic method of age estimation using pulp/tooth ratio of mandibular premolars on a South Indian sample and derive population-specific equations for a more accurate estimation of age. This retrospective study was carried out using 150 digital orthopantomograms of patients (age between 20-70 years) of Indian origin from the records of our institution. Approval from the institutional ethics committee was obtained prior to commencing the study. The images of the orthopantomograms were recorded on computer files. Following the technique proposed by Cameriere et al. the radiographic images were saved as high resolution JPEG files and imported to Photoshop Image processing software and Image J (NIH USA). The focus of the study was the mandibular first and second premolar. A lasso tool was used to delineate the external perimeter of the tooth as well as the pulpal perimeter and two variables obtained. Linear regression equations were derived for predicting the age of the individuals separately for each gender. The pulp/tooth area ratio of mandibular premolar was seen to decrease significantly with age. Multiple regression equations were derived based on age as the dependent variable and the tooth/pulp ratios as predictors. Thus, the pulp/tooth ratio is a valuable method in the estimation of age of subjects of Indian origin.