Advances in Dental Research, Vol 3, 120-125, Copyright © 1989 by International & American Associations for Dental Research
Developmental defects of enamel in Chinese girls and boys in Hong Kong
N. M. King
The FDI (DDE) Index--with some modifications and a re-designed recording
sheet--was used to determine the prevalence of the different types of
developmental defects of enamel. The public water supply contained 1.0 ppm
when the children were bron and 0.7 ppm at the time of the examinations.
All surfaces of the teeth of 460 female and 484 male, 12-year-old, Chinese
children were examined after the teeth had been cleaned and dried. Mouth
prevalences for all types of opacities, hypoplasia, and discoloration were
99.6%, 82.8%, and 16.6%, respectively. There was no apparent statistically
significant difference between girls and boys. However, a statistically
significant difference was seen between the sexes for white patches (p less
than 0.05), missing enamel (p less than 0.05), and horizontal grooves (p
less than 0.01). There were 811 (85.7%) children with more than 13 teeth
affected by opacities, and 417 (44.2%) children had more than four teeth
affected by hypoplasia. The most common defect was the diffuse white patch,
and the least common was the vertical groove. There were 189 (39.0%) boys
with between four and 12 teeth affected by more than two types of defect
per tooth. White lines were the most difficult defect to diagnose
reproducibly. Intra-examiner reproducibility for all other defects achieved
levels of "almost perfect" and "substantial" by calculation of the Kappa
coefficient.
