Abstract
The Wits appraisal by which the occlusal plane of the mandibular protrusion in the deciduous dentition and the early stage of the mixture dentition were assumed to be planes of reference were examined, adopting the infants with mandibular protrusion and normal occlusion in Hellman's dental age II A and III A as a testees, using the roentgenographic cephalogram. The items examined were effective for the diagnosis of the harmonization of the position before and behind the maxilla and mandible alveolar base part with the effectiveness based on the plane of occlusion in a morphology analysis of the mandibular protrusion of the deciduous dentition and the early stage of the mixture dentition, and the relation to other morphological analysis items. And the following conclusions were obtained,
1. When comparing, it was found that the AO-BO values of the group with mandibular protrusion and normal occlusion, the group with mandibular protrusion stage II A and stage III A intentionally showed high values compared with a normal group.
2. Concerning the Wits appraisal and other craniofacial form appraisal, the relationship of Wits appraisal and ANB showed a significant, positive correlation in both stage II A and stage Ill A group with mandibular protrusion and group with normal occlusion. A significant correlation was not found between the Wits appraisal and SN to occlusal plane angle, and between the Wits appraisal and cant of occlusal plane.
