Growth changes in the dentition and the facial skeleton of boys and girls with Class I malocclusion from 10 to 14 years of age are presented, and the changes are compared with those for children with Class II Division 1 malocclusion. Radiographs of 335 children with Class II Division 1 malocclusion and 273 Class I controls were assessed. Radiographs were converted to x and y coordinate data, and 52 commonly used linear, angular, and coordinate axis measurements were made. Both the Class II Division 1 and the control groups were subdivided into 6 samples according to sex and skeletal age (10, 12, and 14 years +/- 6 months; chronological age ranged from 8.5 to 15.5 years). The mean plots from the coordinate data for the Class I boys and girls at 14 years were superimposed over the mean plots for the 10-year-old groups, creating circumpubertal growth standards. The standards are supported by growth vector diagrams and other data and lead to the following conclusions: (1) boys and girls with Class I malocclusion differ distinctly from each other in the amount and the direction of circumpubertal growth; (2) radiographic composite standards are useful and accurate clinical tools to show mean dentofacial skeletal growth and change between 10 and 14 years of age; (3) compared with the controls, the maxillary dentition of girls with Class II Division 1 malocclusion grows more horizontally, the maxillary (but not the mandibular) incisors procline farther, and the mandible grows more horizontally; (4) compared with the controls, the midfacial convexity in Class II Division 1 boys is markedly increased, due to more horizontal growth at A-point and less horizontal growth at nasion and pogonion, and maxillary and mandibular anterior teeth are proclined farther; (5) angular measurements involving S, N, A-point, B-point, and Pog are useful only when the position of N is known; and (6) cranial base flexure bears no relationship to the development of Class II Division 1 malocclusion.