Korean J Orthod 2009; 39(5): 300-309 https://doi.org/10.4041/kjod.2009.39.5.300
First Published Date October 31, 2009, Publication Date October 30, 2009
Copyright © The Korean Association of Orthodontists.
Soo-Byung Park, DDS, MSD, PhD, aJeong-Heuy Park, DDS, MSD, bYun-Hoa Jung, DDS, MSD, PhD, cBong-Hye Jo, DDS, MSD, PhD, c and Yong-Il Kim, DDS, MSDd
aProfessor, Department of Orthodontics, School of Dentistry, Pusan National University, Korea.
bGraduate Student, Department of Orthodontics, School of Dentistry, Pusan National University, Korea.
cAssociate Professor, Department of Oral & Maxillofacial Radiology, School of Dentistry, Pusan National University, Korea.
dFellow, Department of Orthodontics, School of Dentistry, Pusan National University, Korea.
Correspondence to: Yong-Il Kim. Department of Orthodontics, School of Dentistry, Pusan National University Hospital, 305, Gudeok-ro, Seo-gu, Busan 623-739, Korea. +82 51 240 7443, Email: kimyongil@pusan.ac.kr
Objective
The purpose of this study was to evaluate the correlation between menton deviation and dental compensation in facial asymmetry.
MethodsTooth 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.
ResultsFrom the result, Menton deviation was negatively correlated with mandibular first molar's angular measurement (Δ∠LM6-Mn plane (dev.-ndev.)) and positively with maxillary fist molar's angular measurement (Δ∠UM6-FH plane (dev.-ndev.)) (p < 0.01). Two angular measurements (Δ∠ LM6-Mn plane (dev.-ndev.), Δ∠UM6-FH plane (dev.-ndev.)) explained the variability in menton deviation with a significant r2 value of 0.589.
ConclusionsThis 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.
Keywords: Cone-beam computed tomography, Presurgical orthodontics, Occlusal plane, Menton deviation, Facial asymmetry
Korean J Orthod 2009; 39(5): 300-309 https://doi.org/10.4041/kjod.2009.39.5.300
First Published Date October 31, 2009, Publication Date October 30, 2009
Copyright © The Korean Association of Orthodontists.
Soo-Byung Park, DDS, MSD, PhD, aJeong-Heuy Park, DDS, MSD, bYun-Hoa Jung, DDS, MSD, PhD, cBong-Hye Jo, DDS, MSD, PhD, c and Yong-Il Kim, DDS, MSDd
aProfessor, Department of Orthodontics, School of Dentistry, Pusan National University, Korea.
bGraduate Student, Department of Orthodontics, School of Dentistry, Pusan National University, Korea.
cAssociate Professor, Department of Oral & Maxillofacial Radiology, School of Dentistry, Pusan National University, Korea.
dFellow, Department of Orthodontics, School of Dentistry, Pusan National University, Korea.
Correspondence to: Yong-Il Kim. Department of Orthodontics, School of Dentistry, Pusan National University Hospital, 305, Gudeok-ro, Seo-gu, Busan 623-739, Korea. +82 51 240 7443, Email: kimyongil@pusan.ac.kr
Objective
The purpose of this study was to evaluate the correlation between menton deviation and dental compensation in facial asymmetry.
MethodsTooth 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.
ResultsFrom the result, Menton deviation was negatively correlated with mandibular first molar's angular measurement (Δ∠LM6-Mn plane (dev.-ndev.)) and positively with maxillary fist molar's angular measurement (Δ∠UM6-FH plane (dev.-ndev.)) (p < 0.01). Two angular measurements (Δ∠ LM6-Mn plane (dev.-ndev.), Δ∠UM6-FH plane (dev.-ndev.)) explained the variability in menton deviation with a significant r2 value of 0.589.
ConclusionsThis 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.
Keywords: Cone-beam computed tomography, Presurgical orthodontics, Occlusal plane, Menton deviation, Facial asymmetry