title: Determination of normal maxillary transverse dimension by using intercanine width and interpalatal first molar width.
abstract: BACKGROUND
  Malocclusion in the vertical and sagittal planes is easy to observe whereas it is difficult to diagnose malocclusion in the transverse plane. There are yet no criteria defining a normal transverse occlusion.
  
  
  OBJECTIVE
  The aim of this study was to identify a ratio that defines a normal transverse occlusion.
  
  
  METHODS
  This was a retrospective study.
  
  
  METHODS
  A total sample of 151 maxillary dental models (M = 55, F = 96) in the age range of 12-16 years were randomly selected, with 73 models in control group and 78 in the study group. All the models were mixed up and given to an operator for the measurement of intercanine width (ICW) and inter-palatal molar width (IPMW).
  
  
  METHODS
  The data were statistically analyzed using SPSS software version 16.0. Chi-square test was performed to test the statistical significance difference between the groups at p ≤ 0.05.
  
  
  RESULTS
  Nearly 98.60% of normal arches were found to have an IPMW to ICW ratio of 1:1 ± 0.05. On further analysis, it was found that when IPMW ≥37.45 mm, then the case may be considered to have normal arches, and if the ratio between IPMW to ICW is 1.15:1 ± 0.05 or more and IPMW is <34.92 mm, then the case may be identified as deficient arch.
  
  
  CONCLUSIONS
  The IPMW-to-ICW ratio can be used to differentiate deficient and normal arches. This hypothesis (Banker's hypothesis) is an easy and noninvasive method, using only two parameters, developed to help clinicians in identifying normal transverse dimension.
authors.affiliation: Department of Orthodontics, Goenka Research Institute of Dental Science, Gujarat University, Gandhinagar, Gujarat, India.
authors.forename: Alka M
authors.initials: AM
authors.lastname: Banker
authors.affiliation: Department of Oral Pathology, Government Dental College and Hospital, Gujarat University, Ahmedabad, Gujarat, India.
authors.forename: Jayasankar P
authors.initials: JP
authors.lastname: Pillai
authors.affiliation: Research Assistant, Pulse Orthodontics, 108, Swastic Society, Navarangpura, Ahmedabad, Gujarat, India.
authors.forename: Kinjal D
authors.initials: KD
authors.lastname: Patel
mesh_terms: D000293:Adolescent; D002648:Child; D003481:Cuspid / Q000033:anatomy & histology*; D003724:Dental Arch / Q000033:anatomy & histology; D003766:Dental Occlusion; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000033:anatomy & histology*; D008963:Molar / Q000033:anatomy & histology*; D012189:Retrospective Studies