• The korean journal of orthodontics
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• v.36 no.5
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• pp.380-387
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• 2006

Objective: The purpose of this study was to compare the right and left differences of frontal ramal inclination in chin-deviated individuals. Methods: Thirty adult patients with clinically apparent chin deviation were selected as the chin-deviated group, and 30 adult patients with symmetric faces were selected as the control group. On the posteroanterior cephalograms, the frontal ramal inclination was measured, and the right and left differences were compared and analyzed. Results: While the control group did not show right and left differences of frontal ramal inclinations, the chin-deviated individuals showed right and left differences of frontal ramal inclination. In chin-deviated individuals, the frontal ramal inclinations of the non-deviated side were statistically greater than those of the deviated side. The right and left differences of frontal ramal inclinations, with menton deviation and the right and left differences of maxillary heights showed statistically significant correlation. Conclusion: We conclude that the frontal ramal inclinations should be considered in the diagnosis of facial asymmetry.

• The korean journal of orthodontics
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• v.39 no.5
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• pp.300-309
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• 2009

Objective: The purpose of this study was to evaluate the correlation between menton deviation and dental compensation in facial asymmetry. Methods: Tooth axis and distance of first molar and canine to the reference plane were investigated by cone-beam computerized tomography. The subjects consisted of 50 patients with asymmetric mandibles (male 21, female 29, mean age 24.3 years). Control groups were also assessed (male 11, female 9, mean age 25.6 years). Nine measurements (5 linear measurements and 4 angular measurements) were measured in order to evaluate the correlation between menton deviation and the linear and angular difference of first molar and canine in the deviated and none-deviated sides using the defined MPR images. The differences between deviated and non-deviated side, according to menton deviation, were statistically analyzed using stepwise multiple regression analysis. Results: From the result, Menton deviation was negatively correlated with mandibular first molar's angular measurement (${\Delta\angle}LM6$-Mn plane (dev.-ndev.)) and positively with maxillary fist molar's angular measurement (${\Delta\angle}UM6$-FH plane (dev.-ndev.)) (p < 0.01). Two angular measurements (${\Delta\angle}LM6$-Mn plane (dev.-ndev.), ${\Delta\angle}UM6$-FH plane (dev.-ndev.)) explained the variability in menton deviation with a significant $r^2$ value of 0.589. Conclusions: This study suggests that the tooth axis of upper and lower first molars leans towards the deviated side of Menton when there is mandibular asymmetry with Menton deviation.