An additional classification for congenital aural atresia. Its impact on the predictability of surgical results.

An additional classification of type II of congenital aural atresia (to Altmann) is presented. This subclassification proved to be useful in predicting the change on a servicable hearing level after a canal plasty procedure. Also a correlation has been noted between the postoperative hearing level and the degree of malformation of the auricle. In type II A atresia the rate of success is so good, that a small group of patients with unilateral atresia and this class of anomally can also be expected to benefit from surgery.