Some epidemiological and scanning electron microscopic features of crazing of the dental enamel of Polynesians.
The prevalence of enamel crazing was determined from the maxillary incisors and canines of 1,109 Tongan residents aged 5-20 years, 1,417 Cook Island residents aged 6-20 years, 520 French Polynesian residents aged 10-15 years, and 92 New Zealand-born and -resident Polynesians aged 11-18 years. Crazing occurred in 22 percent of Tongans, 7 percent of Cook Islanders, but not in French Polynesians or New Zealand-born Polynesians. Cracks become clinically apparent at about 8 years of age; were more common in males than females; and became more common with increasing age. The central incisors were the most commonly affected of the maxillary anterior teeth. Cross-sections of teeth with crazing viewed by light and scanning electron microscopy appeared similar to other stained cracks. The indications are that crazing is a post-eruptive change caused by trauma from local environmental factors resulting in stress fractures. The significance of crazing on enamel structure and strength is unknown, but it is probably minor without long-term disadvantages. The prevalence of crazing may prove useful in anthropology as an indicator of the use of teeth as tools and in assessing the "modernisation" of a population.
Hoffman
M P
MP
Cutress
T W
TW
Crooks
M C
MC
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003743:Dental Enamel / Q000293:injuries* / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007180:Incisor / Q000293:injuries / Q000648:ultrastructure; D008297:Male; D008855:Microscopy, Electron, Scanning; D009520:New Zealand; D011114:Polynesia; D014058:Tonga; D014082:Tooth Fractures / Q000453:epidemiology* / Q000473:pathology