title: New classification of crown forms and gingival characteristics in taiwanese.
abstract: OBJECTIVE
  The aim of the investigation was to examine the forms of the crowns in the maxillary anterior tooth segment and corresponding gingival characteristics among healthy Taiwanese subjects.
  
  
  METHODS
  The crown width at the apical third (CW), length (CL), gingival angle (GA) and the interdental papilla height were assessed from the diagnostic stone model using a calibrated periodontal caliper. A CW/CL-ratio was calculated for each tooth and averaged for each tooth region. Gingival thickness (GT) and width of keratinized gingiva (WG) were measured clinically.
  
  
  RESULTS
  The cluster analysis revealed 3 classifications of crown forms: narrow (N), compound (C) and square (S) types. There was a significant difference among the 3 classifications with respect to CW/CL-ratio, GT, and WG (p < 0.0001).
  
  
  CONCLUSIONS
  The results demonstrated varied crown forms and corresponding gingival characteristics in Caucasian and Taiwanese. The new classifications hinted that there was a polymorphism in different races and could be a valuable esthetic guideline and reference for anterior tooth rehabilitation, including various periodontal and restorative treatments and anterior implant placement procedures in Taiwanese.
authors.affiliation: Department of Periodontics, Chung-Ho Memorial Hospital, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan.
authors.forename: Yu-Hsiang
authors.initials: YH
authors.lastname: Chou
authors.forename: Chi-Cheng
authors.initials: CC
authors.lastname: Tsai
authors.forename: Jen-Chyan
authors.initials: JC
authors.lastname: Wang
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Ho
authors.forename: Kun-Yen
authors.initials: KY
authors.lastname: Ho
authors.forename: Chuen-Chyi
authors.initials: CC
authors.lastname: Tseng