PATIEN'l' J. Z., a white boy 13 years 9 months of age, had a Class II, Division 1 malocclusion. This diagnosis could be determined only in the canine area, since no mandibular molars were present on either the right or the left side. The maxillary arch was normal in width and in protraction. The maxillary right second premolar was blocked out lingually and rotated mesially, and the maxillary le...