title: Fluctuating dental asymmetry of multiple crown variables measured by an image analysis system.
abstract: OBJECTIVE
  Fluctuating dental asymmetry as an indication of the effect of environmental insults during tooth development requires further investigation. The aim of this study was to assess asymmetry in tooth crown dimension for the increased range of parameters possible with image analysis compared to previous manual measurements.
  
  
  METHODS
  Study models of 25 male and 25 female white Caucasian subjects were measured from buccal and occlusal views to determine mesio-distal, bucco-lingual, occluso-gingival and tooth surface area dimensions using image analysis. Method errors were assessed by the repeatability coefficient RC and asymmetry assessed calculating intra-class correlation coefficients between pairs of antimere teeth.
  
  
  RESULTS
  The method errors calculated using RC were small. There was a high degree of symmetry with correlation coefficients with a range of 0.67-0.96 for linear measurements and 0.80-0.97 for tooth surface areas. No significant differences were found between the genders or between the upper and lower jaws. Asymmetry tended to follow a pattern in morphogenic tooth fields with the mesial tooth showing greater symmetry than the more distal. There were differences in the degree of symmetry among the variables measured with the mesio-distal dimension showing the greatest symmetry.
  
  
  CONCLUSIONS
  This new technique was reliable and readily applicable, providing also a greater range of measurements. While the asymmetry generally followed a similar pattern to earlier manual studies, there were variations in the degree of symmetry between different parameters.
authors.affiliation: Department of Oral Health and Development, University of Sheffield, School of Clinical Dentistry, Claremont Crescent, Sheffield, South Yorkshire S10 2TA, UK.
authors.forename: Khaled
authors.initials: K
authors.lastname: Khalaf
authors.forename: Claire
authors.initials: C
authors.lastname: Elcock
authors.forename: Richard N
authors.initials: RN
authors.lastname: Smith
authors.forename: Alan H
authors.initials: AH
authors.lastname: Brook
mesh_terms: D000293:Adolescent; D002648:Child; D019229:Dentition, Permanent; D005260:Female; D005783:Gender Identity; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009811:Odontometry; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D019228:Tooth Crown / Q000033:anatomy & histology*