Study on Korean skeletal Class III craniofacial pattern by counterpart analysis

Sohn, Byung Wha; Lee, Kee Joon; Mo, Sung Seo

Abstract

Enlow's counterpart analysis reflects the characteristics of each individual sample to find out the cause of the malocclusion and further applying them to the clinic. Enlow's counterpart analysis was performed on 100 Korean samples (50 male, 50 female) with normal occlusion and 100 skeletal class III patients (50 male, 50 female) scheduled for orthognathic surgery. The following conclusions were obtained. 1. The cause of malocclusion in skeletal class III patients were complex and interrelated ; backward upward rotation of the cranial base, forward inclination of the ramus, increase in the mandibular body length, and posteriorly located maxilla. 2. Seen on R2 (male-1.68mm, female-2.33mm), in skeletal class III, the maxilla is more posteriorly located than the normal group. 3. The cause of malocclusion in skeletal class III patients, consists of retrognathic maxilla(A1) male 22%, female 26%, prognathic mandible(B1) male 44%, female 34%, and combination of an retrognathic maxilla and prognathic mandible were male 28%, female 38%. 4. There was no significant difference in the anterior-posterior length of the maxilla(A4) between skeletal class III males with the normal group, while in the female subjects, the skeletal class III group showed a smaller maxilla(A4) compared to the normal group. 5. In skeletal class III patients the proganthic mandible was primarily caused by the inclination of the ramus(R3, R4) and mandibular body length(B4, B6) rather than ramus width(B3).