Among the causes of canker sores, a genetic predisposition might be the biggest cause, says Michael Martin, DMD, PhD, lead author of the study. "When both parents have a history of canker sores, the likelihood of their children developing them can be as high as 90 percent," he says.

The most serious side effect of canker sores is sharp pain in the mouth, which can interfere with an individual's quality of life and affect their eating, drinking or speech.  Dr. Martin revealed that "in addition to speeding healing of the canker sores, the adhesive patch helped to reduce pain after just three days of treatment."