Monday I wrote about Olympic swimmer Ryan Lochte’s decorative dental grill.

Today I’m writing about a phenomenon at the other end of the dental-care spectrum. Research published Wednesday morning in the Journal of the American Dental Association sheds light on the dental health of people whose intellectual or developmental disabilities (IDDs) may interfere with their care.

Researchers at Tufts University School of Dental Medicine in Boston examined a year’s worth of electronic dental records for 4,732 adults (ages 20-98) with IDDs. The patients’ dental care was provided through clinics, supported by the state of Massachusetts and run by Tufts, designed to provide dental care to people with such disabilities.

They found that 10.9 percent of the study subjects had no teeth; 88 percent had a history of dental caries (cavities), and nearly a third (32.2 percent) had untreated caries. More than 80 percent had periodontitis, and 18 percent had gingivitis (without periodontitis).

For comparison’s sake, the study cites CDC data showing that among the general population of adults age 20 and up, 7.6 percent have no teeth and 22.7 percent have untreated caries.

Though all the patients in this study had ready access to sound dental care, physical, cognitive and behavioral issues may get in the way of their benefiting from that care. In this study, nearly 40 percent of the patients required “behavioral assistance” to allow them to receive dental care. For those (unlike those in this study) who don’t have access to care provided by practitioners skilled at working with people with IDDs, the study notes, care may be compromised by practitioners’ lack of experience and expertise in handling such patients’ special needs.

Poor dental health can lead to other health problems. For instance, periodontal disease has been linked to such conditions as diabetes, cardiovascular disease and Alzheimer’s disease.

The authors write that their attempt to quantify dental-health disparities should help inform efforts to develop interventions to better serve the needs of people with IDDs.