Elderly residents forced out of their homes by the 2011 earthquake and tsunami disaster are at greater risk of dental problems than those who were not so badly affected, researchers say.
Stress, along with dietary changes and a lack of opportunities to brush teeth, are among the possible factors, according to a team from Tohoku University and other institutions.
The researchers surveyed 3,039 people aged 65 or older living in Iwanuma, Miyagi Prefecture.
Of the 2,332 respondents who answered all questions, a comparison was made of the state of their teeth in 2010, prior to the disaster, and in 2013.
It found that 7.4 percent of the 1,805 respondents whose financial situation had not changed as a result of the disaster lost at least one tooth during the study period, whereas the corresponding ratio was 12.4 percent among the 145 subjects who said their financial state became tighter.
When age, income and other factors were taken into consideration, the worsening of an individual's financial situation because of the disaster was found to have increased the risk of losing teeth by 8 percent, the researchers said.
The survey found that disaster-affected people are vulnerable not only to depression, post-traumatic stress disorder and other mental health problems but also to a deterioration of dental health.
The researchers said possible preventive measures include distributing toothbrushes and setting aside tooth-brushing areas at evacuation centers.