Dental enamel defects in first-degree relatives of coeliac disease patients. To find out whether dental changes can be used to screen for coeliac disease among apparently healthy relatives of patients with the disorder, 56 healthy first-degree relatives of such patients were subjected to dental examination and small bowel biopsy. 25 had coeliac-type general permanent-tooth enamel lesions. All 7 who had histological evidence of coeliac disease also had enamel lesions. The finding that enamel defects may occur without small bowel changes must be borne in mind in screening. The coeliac-type enamel changes were strongly associated with HLA-DR3, and most of the DR3 alleles belonged to the extended haplotype A1; B8; DR3 group. 