Gum disease and tooth loss may be linked to brain shrinkage in the hippocampus, a region that has significant ties to memory and Alzheimer’s disease, a group in Japan has reported.
Researchers led by Dr. Satoshi Yamaguchi, PhD, of Tohoku University in Sendai, Japan, studied longitudinal associations between the number of teeth present and hippocampal atrophy in a group of late middle-aged and older adult subjects.
“Fewer teeth were associated with a faster rate of left hippocampal atrophy in patients with mild periodontitis, whereas having more teeth was associated with a faster rate of atrophy in those with severe periodontitis,” the group wrote.
The study involved 172 people with an average age of 67 who did not have memory problems at the beginning of the study. Participants had dental exams and took memory tests in addition to undergoing brain magnetic resonance imaging to measure the volume of their hippocampus both at the beginning of the study and again four years later.
In addition, researchers counted the number of teeth for each participant and checked for gum disease by assessing periodontal probing depth, a measurement of the gum tissue.
After adjusting for age, the group reported that for people with mild gum disease, the increase in the rate of brain shrinkage due to one less tooth was equivalent to nearly one year of brain aging. Conversely, for people with severe gum disease, the increase in brain shrinkage due to one more missing tooth was equivalent to 1.3 years of brain aging.
“The findings suggest that retaining teeth with severe gum disease is associated with brain atrophy. Controlling the progression of gum disease through regular dental visits is crucial, and teeth with severe gum disease may need to be extracted and replaced with appropriate prosthetic devices,” Yamaguchi said, in a news release.
Future studies are needed with larger groups of people, he noted. The study was published July 5 in Neurology.