Biometric analysis of the clinical crown and the width/length ratio in the maxillary anterior region

J Prosthet Dent. 2015 Jun;113(6):565-70.e2. doi: 10.1016/j.prosdent.2014.11.006. Epub 2015 Apr 7.

Abstract

Statement of problem: Restorative dentistry often involves correcting tooth size discrepancies. Therefore, dental biometrics should play an important role in the planning of an esthetic restoration.

Purpose: The purpose of this study was to analyze the clinical crown width, length, and width/length ratio of maxillary central incisors, lateral incisors, and canines in an adult population. The study also aimed to determine whether a correlation exists between natural tooth dimensions and the optimal tooth dimension guidelines suggested for planning esthetic restorations.

Material and methods: Stone casts were poured from irreversible hydrocolloid impressions of 412 healthy adult participants. These casts were used to measure the maximum mesiodistal width and maximum crown-root length of the maxillary central incisors, lateral incisors, and canines with a digital precision caliper (0.01 mm). The width/length ratio was calculated for each tooth, and 40 casts were selected to test the reliability of the measuring method.

Results: The mean age of the participants in the sample was 33.94 years; 60.7% were women and 39.3% were men. The mean width value was 8.71 mm for central incisors, 6.75 mm for lateral incisors, and 7.81 mm for canines. The mean length was 10.23 mm for central incisors, 8.59 mm for lateral incisors, and 9.93 mm for canines. The average width/length ratio was 85% for central incisors and 79% for lateral incisors and canines.

Conclusion: The data obtained from the population studied are similar to those from previous research studies with similar methodology. However, great discrepancies in the absolute values were found when compared with other studies of ideal tooth dimension guidelines on the personal preferences and the esthetic perception of dentists. The perception of what is considered natural seems to differ from what is considered esthetically perfect.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Biometry / methods
  • Cuspid / anatomy & histology*
  • Esthetics, Dental
  • Female
  • Humans
  • Incisor / anatomy & histology*
  • Male
  • Models, Dental
  • Odontometry / methods*
  • Patient Care Planning
  • Sex Factors
  • Tooth Crown / anatomy & histology*
  • Tooth Root / anatomy & histology