title: Comparison of different parameters for recording sagittal maxillo mandibular relation using natural head posture: A cephalometric study.
abstract: BACKGROUND
  Commonly used parameters for anteroposterior assessment of the jaw relationship includes several analyses such as ANB, NA-Pog, AB-NPog, Wits appraisal, Harvold's unit length difference, Beta angle. Considering the fact that there are several parameters (with different range and values) which account for sagittal relation, and still the published literature for comparisons and correlation of these measurements is scarce. Therefore, the objective of this study was to correlate these values in subjects of Indian origin.
  
  
  METHODS
  The sample consisted of fifty adult individuals (age group 18-26 years) with equal number of males and females. The selection criteria included subjects with no previous history of orthodontic and/or orthognathic surgical treatment; orthognathic facial profile; Angle's Class I molar relation; clinical Frankfort Mandibular plane angle FMA of 30±5° and no gross facial asymmetry. The cephalograms were taken in natural head position (NHP). Seven sagittal skeletal parameters were measured in the cephalograms and subjected to statistical evaluation with Wits reading on the true horizontal as reference. A correlation coefficient analysis was done to assess the significance of association between these variables.
  
  
  RESULTS
  ANB angle showed statistically significant correlation for the total sample, though the values were insignificant for the individual groups and therefore may not be very accurate. Wits appraisal was seen to have a significant correlation only in the female sample group.
  
  
  CONCLUSIONS
  If cephalograms cannot be recorded in a NHP, then the best indicator for recording A-P skeletal dimension would be angle AB-NPog, followed by Harvold's unit length difference. However, considering biologic variability, more than one reading should necessarily be used to verify the same.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Sardar Patel Post Graduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India.
authors.forename: Ashish Kumar
authors.initials: AK
authors.lastname: Singh
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, S.D.M. College of Dental Sciences and Hospital, Dharwad, Karnataka, India.
authors.forename: Sanjay V
authors.initials: SV
authors.lastname: Ganeshkar
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Sardar Patel Post Graduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India.
authors.forename: Praveen
authors.initials: P
authors.lastname: Mehrotra
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Sardar Patel Post Graduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India.
authors.forename: Jitendra
authors.initials: J
authors.lastname: Bhagchandani
keywords: Natural head position; sagittal skeletal relation; true horizontal