Evaluation of DNA damage in tobacco associated human buccal cells using comet assay.

AIM AND OBJECTIVE: To assess the DNA damage in tobacco associated human buccal cells using comet assay. METHODS: The study included 75 study subjects, which were divided into 3 groups on the basis of tobacco usage. Group I - 25 individuals with no history of tobacco usage, Group II - 25 individuals with tobacco usage but without oral lesions and Group III - 25 individuals with tobacco associated oral lesions. Cytological smears collected from these individuals were used to assess the tobacco associated DNA damage by measuring the tail length in the comet assay method. RESULTS: The average tail length was found to be 1.46 µm in the normal mucosa, 2.86 µm in tobacco users without oral lesions, 3.86 µm in the lesional sites of tobacco users and 3.67 µm in the non-lesional sites of these individuals. Factors like age, gender, duration and different forms of tobacco habit had their own impact on the oral mucosa. CONCLUSION: Comet assay helps assess the subclinical genetic changes of oral mucosa even before the clinical manifestations of the precancerous lesions appeared due to tobacco usage. Thus, comet assay may bloom out as a novel adjuvant tool for the prevention of oral cancer in the near future.

Digitized Morphometric Analysis using Maxillary Canine and Mandibular First Molar for Age Estimation in South Indian Population.

BACKGROUND: In recent years, the estimation of age in living individuals have become important to solve judicial or civil problems. Secondary dentin deposition occurs as the age advances and can be measured by calculating the reduction in pulp chamber through Noninvasive radiograph techniques. AIM: The aim is to derive precise population specific formulae for age estimation. MATERIALS AND METHODS: Digitalized Orthopantomography of 150 subjects, was retrieved. The subjects were divided into study and test group. Pulp tooth area ratio was recorded from the maxillary canine and pulp chamber crown root trunk height ratio was recorded from a mandibular first molar. STATISTICAL ANALYSIS: Regression equation was derived from study group subjects and this equation was used to estimate the age of subjects in the test group. RESULTS: No significant differences were seen between mean chronological age and mean estimated age (p-value- 0.157). Mean Absolute Error (MAE) was estimated to be 2.76 years. The percentage of estimated ages in test sample < ± MAE was 72%. The difference was higher in the group I and II (p-value- 0.001 and 0.002). CONCLUSION: The equation derived from the anterior and posterior teeth together gave more accurate results in the present study. The prediction accuracy can further be enhanced by using multiple teeth or by utilizing other linear measurements in the same teeth.