title: A cephalometric study to establish the relationship of the occlusal plane to the three different ala-tragal lines and the Frankfort horizontal plane in different head forms.
abstract: BACKGROUND
  The aim of the study is to compare the relationship of the occlusal plane to 3 different ala-tragal lines, namely the superior, middle and inferior lines, in individuals having different head forms and its relation to the Frankfort horizontal plane.
  
  
  METHODS
  A total of 75 lateral cephalometric radiographs of subjects with natural dentition, having full complement of teeth, between the age group of 18-25 were screened and selected. Lateral cephalogram were made for each subjects in an open mouth position. Prior to making the lateral cephalogram, radiopaque markers were placed on the superior, middle and inferior tragus points and on the inferior border of the ala of the nose. Cephalometric tracing was done over each cephalogram.
  
  
  RESULTS
  In mesiocephalic head form the middle ala-tragal line was most parallel to the occlusal plane having a mean angle of (1.96°). In dolichocephalic headform, the superior ala-tragal line was most parallel to the occlusal plane having a mean angle of (0.48°). In brachycephalic head form, the middle ala-tragal line was most parallel to the occlusal plane having a mean angle of (2.08°). The mean angulations of occlusal plane to FH plane is 11.04°, 10.16° and 10.60° in mesiocephalic, dolichocephalic and brachycephalic head forms, respectively.
  
  
  CONCLUSIONS
  The study concludes that the middle ala-tragal line can be used as a reference for the mesiocephalic head form and the superior ala-tragal line for the dolichocephalic and brachycephalic head form as a reference to establish the occlusal plane.
authors.affiliation: Department of Prosthodontics, Pacific Dental College & Hospital, Debari, Udaipur, Rajasthan, India. Electronic address: spchika@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Subhas
authors.affiliation: Department of Prosthodontics, Coorg Institute of Dental Science, Virjapet, India.
authors.forename: P L
authors.initials: PL
authors.lastname: Rupesh
authors.affiliation: Department of Orthodontics division & Preventive Dentistry, Faculty of Dentistry, Taif University, KSA, Saudi Arabia.
authors.forename: R
authors.initials: R
authors.lastname: Devanna
authors.affiliation: Department of Prosthodontics, Pacific Dental College & Hospital, Debari, Udaipur, Rajasthan, India.
authors.forename: D R V
authors.initials: DRV
authors.lastname: Kumar
authors.affiliation: Department of Conservative & Endodontics, Pacific Dental College & Hospital, Debari, Udaipur, India.
authors.forename: A
authors.initials: A
authors.lastname: Paliwal
authors.affiliation: Department of Prosthodontics, Pacific Dental College & Hospital, Debari, Udaipur, Rajasthan, India.
authors.forename: P
authors.initials: P
authors.lastname: Solanki
mesh_terms: D000293:Adolescent; D000328:Adult; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D002508:Cephalometry / Q000379:methods* / Q000592:standards; D015331:Cohort Studies; D003766:Dental Occlusion; D003824:Denture, Complete; D054644:Ear Auricle / Q000000981:diagnostic imaging; D005260:Female; D006257:Head / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D009666:Nose / Q000033:anatomy & histology; D055815:Young Adult
keywords: Ala-tragal line; Brachycephalic head form; Dolichocephalic head form; Frankfort horizontal plane; Mesiocephalic head form; Occlusal plane