Oral sugar clearance and other caries-related factors in patients with myotonic dystrophy.

The aim of the investigation was to try to explain why patients with myotonic dystrophy (MD) have a high caries prevalence. Seventeen MD patients, 15 of whom had been examined 8 years earlier, and 17 matched, healthy controls participated. In connection with this follow-up examination, the oral sugar clearance was evaluated after chewing a glucose tablet. A paraffin-stimulated whole saliva sample was collected for determination of secretion rate, buffer capacity, and numbers of mutans streptococci and lactobacilli. Dietary score, plaque index, oral muscular coordination, and self-cleaning ability were also recorded. For all factors, the MD patients showed less favorable mean values than the controls; the differences between the groups were statistically significant, except for the bacterial counts and the salivary buffer capacity. Thus, the high caries prevalence in MD patients may be explained by longer oral sugar clearance time, lower salivary secretion rate, higher intake frequency of sugar-containing products, higher plaque index, and less pronounced oral muscular coordination and self-cleaning ability than in healthy individuals.