The tooth-width relation of the incisors in closed bite.

On the basis of various opinions expressed in the literature, "closed bite" is associated in particular with an impaired front-tooth relation. Applying Tonn's index, evaluation of the records (models and cephalograms) of 1,100 patients, however, yielded no evidence of changes in the width ratio of the front teeth with regard to Angle classes, growth type, axial inclination of the central upper incisors, interincisal angle, or overbite.