In a study of 1566 community-dwelling Japanese elderly who were followed for 5 years, the risk of developing dementia was elevated in individuals with fewer remaining teeth.

Individuals with 10-19, 1-9, and no teeth had 62%, 81%, and 63% higher risks of dementia, respectively, than individuals with >20 teeth. Likewise, an inverse association was observed between the number of remaining teeth and the risk of developing Alzheimer's disease.

"Our findings emphasize the clinical importance of dental care and treatment, especially in terms of maintenance of teeth from an early age for reducing the future risk of dementia," said Dr. Tomoyuki Ohara, co-author of the Journal of the American Geriatrics Society study.

Article: Tooth Loss and Risk of Dementia in the Community: the Hisayama Study, Kenji Takeuchi DDS, PhD, Tomoyuki Ohara MD, PhD, Michiko Furuta DDS, PhD, Toru Takeshita DDS, PhD, Yukie Shibata DDS, PhD, Jun Hata MD, PhD, Daigo Yoshida PhD, Yoshihisa Yamashita DDS, PhD, Toshiharu Ninomiya MD, PhD, Journal of the American Geriatrics Society, doi: 10.1111/jgs.14791, published online 8 March 2017.