The “Wits” appraisal of jaw disharmony

Abstract

The “Wits” appraisal of jaw disharmony is a simple method whereby the severity or degree of anteroposterior jaw dysplasia may be measured on a lateral cephalometric head film. The method entails drawing perpendiculars from points A and B on the maxilla and mandible, respectively, onto the occlusal plane. The points of contact of the perpendiculars onto the occlusal plane are labeled AO and BO, respectively. In a sample of twenty-one male and twenty-five female adults selected on the basis of excellence of occlusion, it was found, on the average, that in females points AO and BO coincided and in males point BO was located 1 mm. ahead of point AO. In skeletal Class II jaw dysplasias, point BO would be positioned well behind point AO (positive reading), whereas in Class III skeletal jaw disharmonies, the “Wits” reading would be negative, that is, with point BO ahead of point AO. The advantages of the “Wits” appraisal over that of the conventional ANB angle reading are illustrated and discussed.