乳歯列期反対咬合者の顎顔面頭蓋形態に関する研究

―咬合の変異と顎顔面頭蓋の構造との関連について―

抄録

The purpose of this investigation is to analyze the relationship between craniofacial pattern and intermaxillar disharmony in cases of anterior cross-bite at IIA stage. The materials consisted of standardized lateral head roentgenograms and study models taken from 51 children who had anterior cross-bite and 25 children who had good occlusion. Anterior cross-bite samples were divided into two groups, by the value of ANB angle, group A (ANB≤O; 14 children) and group B (ANB>O: 37 children) .
After the comparison between 3 groups on 90 measurements, the factor analysis was employed in this study on 25 measurements which reveal structure of craniofacial complex, jaw relation, total teeth size and arch length size. In control group and group A, five factors were extracted which acounted for 76% (control) and 78% (group A) of the total variance in each groups, and these were identified as; I) craniofacial rotation, II) total facial hight and depth of midface, III) mandibular morphology, IV) teeth size and arch length size, and V) intermaxillar relationship. And then four factors, in group B, which acounted for 60% of the total variance was extracted. In group A, ANB and over-jet showed high factor loadings on factor I, and cranial base angle (NSBa), one of variances which reveal craniofacial rotation, was significantly smaller than that in control group.