Cephalometric analysis of skeletal Class II malocclusion in Korean adults / 대한치과교정학회지

This study was performed to evaluate horizontal and vertical characteristics according to lateral cephalometry of adult Korean skeletal Class II patients using a selected horizontal and vertical reference planes of Koreans. 60 males and 60 females consisting of freshman of Yonsei University from 1996 to 1997 and patients with history of orthognatic surgery at the Dental Hospital of Yonsei University with a skeletal Class II profile were chosen and compared with 70 males and 70 females with normal occlusion. The skeletal Class II group had the following conditions: 1. Profile composed of a retrognathic mandible or protrusive maxilla; 2. Class II molar and canine key; 3. ANB-greater than 4o; 4. Wits appraisal-greater than 1.0 mm; Cephalometric analysis consisted of 22 skeletal, 25 soft tissue, 12 dental measurements. The results were as follows. 1. There was no considerable vertical measurement difference between the skeletal Class II malocclusion group and the normal occlusion group in skeletal analysis. But, some variations were found between the two groups in soft tissue analysis. 2. Mandibular length of the skeletal Class II malocclusion group was smaller than that of the normal occlusion group. Mandible was more posteriorly positioned in the Class II malocclusion group than in the normal occlusion group. 3. The length and antero-posterior position of the maxilla were not different between the Class II malocclusion and the normal occlusion group. 4. The antero-posterior position of the nose, upper lip and maxillary soft tissue, and nasolabial angle were not different between the two groups. 5. Mandibular soft tissue of the Class II malocclusion group was more posteriorly positioned than that of the normal. 6. The vertical measurements of the incisors(U1-HP, L1-MP) were bigger in the Class II malocclusion group than in the normal, but those of the molars(U6-HP, L6-MP) showed no significant difference between the two groups. 7. Classifying the skeletal Class II malocclusion group according to the antero-posterior position of both jaws, normally positioned maxilla and retruded mandible was 43.3%, both normally positioned maxilla and mandible 28.3%, both retruded maxilla and mandible 20.0%..

Malocclusion with congenital missing of lower incisors / 대한치과교정학회지

Positions, angulation and mesiodistal dimension of lower incisors are important in esthetics, occlusion and post-treatment stability of lower arch. When lower incisor is congenitally missing, problems such as increased overjet and overbite, closing in of adjacent teeth and size/space discrepancies may occur. When creating treatment plans, incisor position and angulation, lip support, anteroposterior skeletal relationship canine-molar relationship, overjet, overbite, remaining growth potential, crowding and anterior tooth ratio have to be considered. For an accurate analysis of incisal size discrepancy, diagnostic model set-up may be helpful. The two patients in this presentation both had two lower incisor missing, but the degree of crowding, skeletal relationship, lip support, molar relationship are different, and therefore treatment plan was different as well. Long term follow-up may be necessary for stability and retention.