RESUMO
The aim of this study was to investigate development of third molars in 18 year old North Indian male population by means of CT scans and 3D software imaging. Methods: A retrospective analysis of CT scans of 50 patients aged 18 years at the time of their scan was conducted, and the developmental stages of the left third molars were evaluated using Demirjian's classification. Demirjian's classification system distinguished eight stages of crown and root development (Stages A-H). Results: The percentile distributions were recorded for each stage of development and variations for different stages were noted. The developmental and physiological changes of the tooth can be correlated to chronological age. Conclusion: The present investigation could provide reference data for third molar development in the North Indian population and maybe used in wider studies of tooth development and age prediction using dental radiographs for forensic and medico- legal purposes.
RESUMO
PURPOSE: To elucidate the effects of the irradiation and calcium-deficient diet on expression of interleukin(IL)-1 during tooth formation of rat molar MATERIALS AND METHODS: The pregnant three-week-old Spague-Dawley rats were used for the study. The control group was non-irradiation/normal diet group, and the experimental groups were irradiation/normal diet group and irradiation/calcium-diet group. The abdomen of the rats on the 9th day of pregnancy were irradiated with single dose of 350 cGy. The rat pups were sacrificed on the 14th day after delivery and the maxillae tooth germs were taken. The specimen were prepared to make sections for light microscopy, and some of tissue sections were stained immunohistochemically with anti-IL-1 antibody. RESULTS: In the irradiation/normal diet group, dental follicle showed fewer blood vessels, mononuclear cells, and fusions of mononuclear cells than in non-irradiation/normal diet group. Alveolar bone showed a few osteoblasts and osteoclasts. Periodontal ligament showed collagen fibers and fibroblasts with irregularity. Weak immunoreactivity for IL-1 was shown in dental follicle, alveolar bone, and periodontal ligament. In the irradiation/calcium-deficient diet group, dental follicle showed sparse cellularity. Alveolar bone showed diminished number of osteoblasts. Periodontal ligament showed irregular collagen fibers and atrophy of cementoblasts and fibroblasts. No immunoreactivity for IL-1 was shown in dental follicle, alveolar bone, and periodontal ligament. CONCLUSION: Irradiation and calcium-deficient diet seems to cause disturbance of the expression of interleukin-1 during tooth formation of rat molar.