Morphometric evaluation of masticator muscles after experimental administration of a carcinogen

In developed countries, over 80% of the cancers in the oral cavity are attributable in part to tobacco smoking. This study evaluates the morpho‐histologic effects in masticator muscles of 7,11‐dimethylbenzanthracene (DMBA), a carcinogen present in tobacco smoke, being administered in a solution by gavage. Sixteen Wistar rats were used, randomly distributed in two groups. The control group had no manipulation. The test group had an experimental administration of DMBA by gavage 3 times in a week, in a dosage of 25 mg/kg. After two weeks, the animals were sacrificed and fragments from the masseter and temporal muscles were collected and analysed in a morphometric program, ImageJ®. At morphometric evaluation, the masseter muscle from the control group had an average area of muscle fibers (A) of 10704±6835 for a 95% confidence interval (CI), while the test group had an A of 9503±4283 for a CI of 95%. The temporal muscle from control group had an A of 8103±2398 for a CI of 95%, while the test group had an A of 16282±7315 for a CI of 95%.