Early developmental traits in class II malocclusion

The occlusal traits of Class II occlusion in the deciduous dentition includ e distal terminal plane of the second deciduous molars, distal canine relat ion, large overjet, and large overbite. Other findings are narrow upper den tal arch and maxillary base and poor anterior spacing. Skeletally, Class II children differ less from normal children. The cranial base, including the base flexure, and the maxilla are normal. The mandibular corpus and lower facial height are shore, the genial angle ic;large, and the dentoalveolar p osition of the mandible is retruded. The height of the ramus is normal, as is the skeletal position of the mandible, with the exception of the chin, w hich becomes slightly retruded after 5 years of age. As most skeletal trait s of Class II occlusion develop later than the occlusal characteristics, it is suggested that no evidence can be found for a skeletal Class II growth pattern in the deciduous dentition. The deficient transversal growth of the maxilla and the sagittal growth of the mandible seem to cause the typical Class II occlusion. Further skeletal changes are likely to develop as secon dary adaptations.