title: Maxillofacial characteristics affecting chin deviation between mandibular retrusion and prognathism patients.
abstract: OBJECTIVE
  To examine and compare the maxillofacial characteristics affecting chin deviation three-dimensionally in facial asymmetry patients with mandibular retrusion and mandibular prognathism.
  
  
  METHODS
  Maxillofacial computed tomography (CT) scan data were obtained from 48 orthognathic surgery patients (24 cases of mandibular retrusion and 24 cases of mandibular prognathism) with facial asymmetry. Although chin deviation was assessed on the basis of the ANS-to-menton line on frontal cephalograms, its contributing factors were evaluated on three-dimensional CT images. Maxillary height, ramus length, frontal ramal inclination, lateral ramal inclination, mandibular body length, and body height were defined on each side, and right-left differences were calculated and analyzed.
  
  
  RESULTS
  In an assessment of chin deviation, subjects in this study showed predominantly left side deviation regardless of the group, and the degree of menton deviation did not reveal significant differences between groups. In a comparison of right-left differences in contributing factors, all values were noted to be greater in the retrusion group, except for body height, which showed no difference between chin-deviated and contralateral sides. In particular, ramus length presented a statistically significant difference between the two groups.
  
  
  CONCLUSIONS
  Based on the same degree of chin deviation in mandibular prognathism and retrusion in this study, results of right-left differences in contributing factors indicate that chin deviations are expressed easily in mandibular prognathism, whereas they occur only with significant right-left differences in relevant maxillofacial structures in individuals with mandibular retrusion.
authors.affiliation: Case School of Dental Medicine, Cleveland, Ohio, USA.
authors.forename: Eun-Jeong
authors.initials: EJ
authors.lastname: Kim
authors.forename: J Martin
authors.initials: JM
authors.lastname: Palomo
authors.forename: Seong-Sik
authors.initials: SS
authors.lastname: Kim
authors.forename: Hoi-Jeong
authors.initials: HJ
authors.lastname: Lim
authors.forename: Kyung-Min
authors.initials: KM
authors.lastname: Lee
authors.forename: Hyeon-Shik
authors.initials: HS
authors.lastname: Hwang
mesh_terms: D000328:Adult; D002508:Cephalometry / Q000379:methods; D016009:Chi-Square Distribution; D002680:Chin / Q000473:pathology*; D054893:Cone-Beam Computed Tomography; D005146:Facial Asymmetry / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008334:Mandible / Q000002:abnormalities* / Q000000981:diagnostic imaging; D011378:Prognathism / Q000150:complications* / Q000473:pathology; D063173:Retrognathia / Q000150:complications* / Q000473:pathology; D014057:Tomography, X-Ray Computed