NEW YORK, Dec. 4 (Xinhua) -- Biting fingernails, gnawing on pen caps and pencil erasers or chewing ice may be your way to deal with boredom or relieve stress, but oral health experts warn that it can lead to cracked, chipped or broken teeth, and may indicate certain underlying health issues, reported The Washington Post on Wednesday.
Chewing ice can cause cracks in the enamel, called craze lines, that can spread, eventually fracturing the tooth. It can also chip or break teeth that are particularly vulnerable, experts said.
"Even though enamel is the hardest substance in the human body, it still can get damaged by repeatedly chewing something that is hard, and ice definitely falls into that category," Holly Shaw, an assistant professor at Columbia University College of Dental Medicine, was quoted as saying.
Chewing ice is in a class of habits known as oral parafunctional activities, which include tooth grinding, thumb sucking, lip biting and other repetitive actions of the mouth. They are extremely common with up to 90 percent of the population exhibiting such behaviors, often because of stress, anxiety and other emotional factors, according to the report.
Craving and eating ice or things with no nutritional value, such as dirt or paper, is associated with certain health issues including iron deficiency, so people who crave ice consistently should speak with their health-care provider, it added.
