title: A determination of occlusal plane comparing different levels of the tragus to form ala-tragal line or Camper's line: A photographic study.
abstract: OBJECTIVE
  The purpose of this study was to determine accurately the part of the tragus to be used to form the Ala-Tragal line or Camper's line in orthognathic profile patients.
  
  
  METHODS
  150 dentate subjects with age of 18-40 years with orthognathic profile were sampled. Life-size lateral digital photographs of the face with fox plane were taken in natural head position. Different angles between Eye-Ear plane and occlusal plane (OT1-OP), Eye-Ear plane and ala-superior border of tragus (OT1-AT1), Eye-Ear plane and ala-middle border of tragus (OT1-AT2) and Eye-Ear plane and ala-inferior border of tragus (OT1-AT3) were calculated using computer software package, AutoCAD 2004. From the three angles formed by the Eye-ear plane (OT1 or FH plane) and the ala-tragal lines, the one closest to the angle formed between Eye-Ear plane (OT1) and occlusal plane (OP) was used to determine the occlusal plane of orientation. The obtained results were subjected to ANOVA F test, Tukey's Honestly significant difference test, followed by Karl Pearson coefficient of correlation test. P values of less than 0.05 were taken as statistically significant.
  
  
  RESULTS
  The mean of base line angle i.e. OT1-OP angle (11.96 ± 4.36) was found to be close to OT1-AT2 angle (13.67 ± 1.93) and OT1-AT3 angle (10.31 ± 2.03), but OT1-OP angle was found to be more closer to OT1-AT3 angle. Comparison of mean angles showed that OT1-OP angle in both males (11.68) and females (12.51) is close to OT1-AT3 angle (males- 11.01, females- 11.95).
  
  
  CONCLUSIONS
  The line joining from ala to the lower border of the tragus was parallel to the occlusal plane in 53.3% of the subjects. There was no influence of the sex on the level of occlusal plane.
authors.affiliation: Department of Prosthodontics and Maxillofacial Prosthetics, Surendera Dental College & Research Institute, Sri-Ganganagar, Rajasthan, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kumar
authors.forename: Sandeep
authors.initials: S
authors.lastname: Garg
authors.forename: Seema
authors.initials: S
authors.lastname: Gupta
keywords: Camper's line; FH plane; Occlusal plane; Simon's classification; Tragus