title: Cone-beam computed tomography based evaluation of rotational patterns of dentofacial structures in skeletal Class III deformity with mandibular asymmetry.
abstract: OBJECTIVE
  The purpose of this study was to assess rotational patterns of dentofacial structures according to different vertical skeletal patterns by cone-beam computed tomography (CBCT) and analyze their influence on menton deviation in skeletal Class III deformity with mandibular asymmetry.
  
  
  METHODS
  The control group consisted of 30 young adults (15 men, 15 women) without any severe skeletal deformity. The asymmetry group included 55 adults (28 men, 27 women) with skeletal Class III deformity and at least 3-mm menton deviation from the midsagittal plane; it was divided into the hyperdivergent and hypodivergent subgroups using a mandibular plane angle cutoff of 35°. Fourteen rotational variables of the dental arches and mandible were measured and compared among the groups. Correlations between menton deviation and the other variables were evaluated.
  
  
  RESULTS
  The asymmetry group showed significantly larger measurements of roll and yaw in the mandible than the control group. The hypodivergent subgroup showed significant differences in maxillary posterior measurements of yaw (p < 0.01) and maxillary anterior shift (p < 0.05) compared with the hyperdivergent subgroup. All the mandibular measurements had significant correlations with menton deviation (p < 0.01). Most measurements of roll were positively correlated with one another (p < 0.01). Measurements of yaw and roll in the posterior regions were also positively correlated (p < 0.05).
  
  
  CONCLUSIONS
  Menton deviation in skeletal Class III deformity with mandibular asymmetry is influenced by rotation of mandibular posterior dentofacial structures. The rotational patterns vary slightly according to the vertical skeletal pattern.
authors.affiliation: Department of Orthodontics, Wonkwang Dental Research Institute, College of Dentistry, Wonkwang University, Iksan, Korea.
authors.forename: Hyeong-Seok
authors.initials: HS
authors.lastname: Ryu
authors.affiliation: Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
authors.forename: Ki-Yong
authors.initials: KY
authors.lastname: An
authors.affiliation: Department of Orthodontics, Wonkwang Dental Research Institute, College of Dentistry, Wonkwang University, Iksan, Korea.
authors.forename: Kyung-Hwa
authors.initials: KH
authors.lastname: Kang
keywords: Cone-beam computed tomography; Facial asymmetry