title: The genial tubercle: A prospective novel landmark for the diagnosis of mandibular asymmetry.
abstract: BACKGROUND
  Identifying menton (Me) on posteroanterior cephalograms and three-dimensional (3D) cone-beam computed tomography (CBCT) images is difficult, because the midpoint of the symphyseal area is not identifiable after the mandibular symphysis fuses at an early age. The aim of this study was to evaluate the reliability of the identification of the genial tubercle (GT) in patients with mandibular asymmetry and to compare it with that of the traditional landmark, Me.
  
  
  METHODS
  The samples comprised 20 CBCT images of adults with mandibular asymmetry. Two examiners performed the identifications and measurements. Me and GT were marked, and the anteroposterior, vertical, and transverse distances to the three reference planes were measured on 3D-reconstructed CBCT images. The intra- and inter-examiner reliability of landmark identification of Me and GT were assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots.
  
  
  RESULTS
  The Me and GT landmarks showed excellent reliability (ICC ≥ 0.993) three-dimensionally. In the transverse evaluation, the ICC values of the GT (range, 0.997-0.999) tended to be slightly higher than those of Me (range, 0.993-0.996). In the Bland-Altman plots for the two separate assessments, Me showed a maximum error of 1.76 mm in the transverse direction, whereas the GT showed a maximum error of 0.96 mm in the 95% limit.
  
  
  CONCLUSIONS
  Our results suggest that both Me and GT are clinically reliable and equally useful landmarks for the evaluation of mandibular asymmetry on CBCT images.
authors.affiliation: Department of Orthodontics, School of Dentistry, Chonbuk National University, Jeonju, Korea.
authors.forename: Seung-Youp
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.; Research Institute of Oral Sciences, College of Dentistry, Gangnung-Wonju National University, Gangneung, Korea.
authors.forename: Dong-Soon
authors.initials: DS
authors.lastname: Choi
authors.affiliation: Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.; Research Institute of Oral Sciences, College of Dentistry, Gangnung-Wonju National University, Gangneung, Korea.
authors.forename: Insan
authors.initials: I
authors.lastname: Jang
authors.affiliation: Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
authors.forename: Geun-Su
authors.initials: GS
authors.lastname: Song
authors.affiliation: Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.; Research Institute of Oral Sciences, College of Dentistry, Gangnung-Wonju National University, Gangneung, Korea.
authors.forename: Bong-Kuen
authors.initials: BK
authors.lastname: Cha
keywords: Cone-beam computed tomography; Genial tubercle; Menton; Three-dimensional cephalometrics