Incidence of the tympanic foramen in the population of Northeast Brazil

The persistence of the tympanic foramen (or of Huschke) in individuals after second childhood constitutes a failure in the embryological development of the tympanic cavity. When present, it is on the anterior wall of the external acoustic meatus and is associated with important otological complications of the temporomandibular joint and external acoustic meatus. To report on the incidence of tympanic foramen in adult dry skulls, belonging to the population of the Northeast of Brazil, 87 adult skulls obtained from the Human Anatomy Laboratory of 4 universities of the Northeast of Brazil, without knowledge of gender, race and age were analyzed. The 174 temporal bones were examined for presence, morphology and measurements of the longitudinal and transverse diameter of the tympanic foramen. The incidence of tympanic foramen was 24.14%, found in 15 (17.24%) skulls on the right and 18 (20.68%) on the left side. Unilateral tympanic foramen was observed in 10 (11.50%) skulls, bilateral in 9 (10.34%) and multiple in 2 (2.30%). The form of tympanic foramen was mainly irregular. In conclusion, the higher prevalence of tympanic foramen found in the Northeast among other studies carried out in Brazil can be attributed to specific dietary habits in the region that could induce the later foramen occlusion