title: [Color measurements of 1,944 anterior teeth of people in southwest of China-discreption].
abstract: OBJECTIVE
  To study the color distribution space of natural anterior tooth crowns of people in southwest China and effects of sex and age on tooth color.
  
  
  METHODS
  The subjects studied consisted of 162 persons aged from 20 to 73 years and born in southwest China. A total of 1,944 healthy anterior teeth were measured in-vivo with a fiber-optical spectrophotometry system.
  
  
  RESULTS
  Statistical analysis showed that the color distribution space of Chinese tooth crowns was wide. The value of L* varied from 42.383 to 67.428, the value of a* from -4.750 to 1.371, the value of b* from 1.88 to 20.268, the value of x from 0.298 to 0.393, the value of y from 0.332 to 0.392, and the value of Y from 19.383 to 34.025. The color difference between the upper and lower limits of 95% confidence was 31.667 CIE delta E units. The difference in colorimetry between male and female was not significant. The results showed that in three sections of teeth (incisal, middle and cervical) the values of L* and a* were negatively related to age (r < 0, P < 0.01); the value of b* was positively related to age just at the cervical and middle sites of teeth (r > 0, P < 0.01) and was not related to age at the incisal site of teeth (P > 0.05).
  
  
  CONCLUSIONS
  The color distribution space of Chinese anterior tooth crowns is wide. There is no difference in the anterior tooth color between male and female subjects. The values of L* and a* and negatively related to age except the value of b*.
authors.affiliation: Department of Oral Medicine, First Affiliated Hospital of Kunming Medical College, Kunming 650032, China.
authors.forename: H
authors.initials: H
authors.lastname: Zhu
authors.forename: Y
authors.initials: Y
authors.lastname: Lei
authors.forename: N
authors.initials: N
authors.lastname: Liao
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003116:Color; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010858:Pigmentation / Q000502:physiology*; D012737:Sex Factors; D013053:Spectrophotometry; D014070:Tooth / Q000737:chemistry*; D019228:Tooth Crown / Q000737:chemistry*