title: [Morphology and developmental groove of maxillary permanent central incisors in Sichuan people].
abstract: OBJECTIVE
  To investigate the morphology of maxillary permanent central incisors of people in Sichuan so as to provide some guidance for emulational restoration of fixed prosthesis.
  
  
  METHODS
  Fifty-eight extracted maxillary permanent central incisors were selected from people in Sichuan. All of the teeth involved in this study were selected according to certain criterions. The length and width of the anatomical crowns, the length and the width of the developmental grooves and the angles formed by the two sides of the developmental grooves were measured.
  
  
  RESULTS
  The average length and width of anatomical crowns in Sichuan people were (11.9 +/- 1.3) mm and (8.7 +/- 0.8) mm respectively. And the average length and width of the developmental grooves were (5.7 +/- 0.9) mm and (2.1 +/- 0.5) mm respectively. There were no statistical differences between the length of the mesial and distal developmental grooves and so were the width. The ratio of the length of crowns to that of the developmental grooves was 2.1, while for the width, it was 4.2. The angles of the mesial and distal developmental grooves formed by its two sides were 23 degrees +/- 4.7 degrees and 23 degrees +/- 5.7 degrees respectively.
  
  
  CONCLUSIONS
  The average length and width of maxillary permanent incisors were close to Wang's report, which means the length and width of the maxillary permanent incisors of people in Sichuan were quite close to those of Chinese people. The ratio of the length of anatomical dental crowns to that of the developmental grooves was steady, and so was the ratio of the width of them. The angles of the developmental grooves were quite steady too. These may help us in making fixed prosthesis.
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Liao
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Li
authors.forename: Yang
authors.initials: Y
authors.lastname: Yao
authors.forename: Ru
authors.initials: R
authors.lastname: Zhang
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Zheng
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Tang
authors.forename: Hai-Yang
authors.initials: HY
authors.lastname: Yu
mesh_terms: D003442:Crowns; D006801:Humans; D007180:Incisor; D008437:Maxilla; D019228:Tooth Crown