Cheek biting and the biting of other areas in the mouth affect 750 out of every 1 million people. Research suggests that this behavior is more common in females than in males.
Cheek biting can affect people of all ages, but it may be more likely in children. In an older survey from 2005, researchers showed that the prevalence of cheek and lip biting in children between the ages of 2 and 17 years in the United States was slightly under 2%.
