This investigation was designed to analyze the degree of dental compensation according to horizontal components of craniofacial skeleton and to investigate correlation between dental compensation and craniofacial pattern in skeletal class III malocclusion. The material selected for this study consisted of standard lateral cephalogram of 59 subjects in normal occlusion group, 91 subjects in mild skeletal class III malocclusion group and 58 subjects in severe skeletal class III malocclusion group. The mild skeletal class III malocclusion group was divided into two groups, one was class III malocclusion without anterior crossbite group and the other was class III malocclusion with anterior crossbite group.
The data were analyzed by Quick-ceph image program. The results were as follows.
1. Mild skeletal class ill malocclusion without anterior crossbite group showed the most labial inclination of upper incisors, followed by severe skeletal class 1Ti malocclusion group and mild skeletal class M malocclusion with anterior crossbite group, the Latter showing the least. The amount of lingual inclination of lower incisors was the largest in severe skeletal class iii malocclusion group, and there was no statistically significant difference between mild skeletal claw Ill malocclusion without anterior-crossbite group and.d mild skeletal class Iii malocclusion with anterior crossbite group.
2. There were little differences in vertical skeletal structure between mild skeletal class Iii malocclusion without anterior crossbite group and mild skeletal class III malocclusion with anterior cwssbite group, they showed statistically significant differences in the upper incisors measurements.
3. The measurements of lower incisors in mild skeletal class III malocclusion without anterior crossbite group and upper incisors in mild skeletal class f malocclusion with anterior crossbite group represented a high correlation with skeletal structure. Especially, LIMPA and LFMIA of lower incisor measurements, and /- U1-FR LUi-SN of upper incisor measurements showed high correlation with skeletal structure in each group.
4. /-WA and LFMIA of lower incisor measurements showed high correlation with skeletal structure in all groups. LUI-FH, LU1-SN and Ui-facial plane(mm) of upper incisor measurements represented higher correlation with skeletal structure than any other upper incisor measurements.
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