title: Three-dimensional analysis of molar compensation in patients with facial asymmetry and mandibular prognathism.
abstract: OBJECTIVE
  To evaluate the characteristic transverse dental compensations in patients with facial asymmetry and mandibular prognathism and to compare features of dental compensations between two types of mandibular asymmetry using 3-dimensional (3D) cone-beam computed tomography (CBCT).
  
  
  METHODS
  Seventy-eight adult patients with skeletal Class I (control group; n  =  33; 19 men and 14 women) or skeletal Class III with facial asymmetry (experimental group; n  =  45; 23 men and 22 women) were included. The experimental group was subdivided into two groups according to the type of mandibular asymmetry: translation type (T-type; n  =  20) and roll type (R-type; n  =  19). CBCT images were acquired before orthodontic treatment and 3D analyses were performed.
  
  
  RESULTS
  The transverse dental distance was significantly different between the two groups only at the palatal root apex of the maxillary first molar (P < .05). In the experimental group, the first molar axes were compensated significantly on both arches except the maxillary nondeviated side. The vertical molar heights were different between the two groups only on the maxillary arch (P < .001). The R-type showed greater mandibular ramal length difference and menton deviation than the T-type (P < .001). In the R-type, transverse compensation of the maxillary first molars was more obvious than with the T-type, which resulted in canting in the maxillary occlusal plane.
  
  
  CONCLUSIONS
  Mandibular asymmetry with prognathism showed a characteristic transverse dental compensation pattern. The mandibular asymmetry type influenced the amount and direction of molar compensation on the maxillary arch.
authors.affiliation: a  Graduate student, Department of Orthodontics, Kyung Hee University School of Dentistry, Seoul, Korea.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Tyan
authors.affiliation: b  Resident, Department of Orthodontics, Kyung Hee University Dental Hospital, Seoul, Korea.
authors.forename: Hong-Sik
authors.initials: HS
authors.lastname: Park
authors.affiliation: a  Graduate student, Department of Orthodontics, Kyung Hee University School of Dentistry, Seoul, Korea.
authors.forename: Munkhshur
authors.initials: M
authors.lastname: Janchivdorj
authors.affiliation: a  Graduate student, Department of Orthodontics, Kyung Hee University School of Dentistry, Seoul, Korea.
authors.forename: Sun-Ho
authors.initials: SH
authors.lastname: Han
authors.affiliation: c  Associate Professor, Department of Orthodontics, Kyung Hee University School of Dentistry, Seoul, Korea.
authors.forename: Su-Jung
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: d  Assistant Professor, Department of Orthodontics, Kyung Hee University School of Dentistry, Seoul, Korea.
authors.forename: Hyo-Won
authors.initials: HW
authors.lastname: Ahn
mesh_terms: D000328:Adult; D002508:Cephalometry; D005146:Facial Asymmetry; D005260:Female; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000628:therapy*; D008334:Mandible; D008963:Molar; D011378:Prognathism
keywords: CBCT; Mandibular asymmetry; Mandibular prognathism; Roll type; Translation type; Transverse compensation