Cavities, also known as dental caries, are a sign of tooth decay. As the decay progresses, small holes begin to develop in the teeth. If not treated, they can become larger and cause more problems.

Gum disease — medically known as periodontitis — affects 47.2% of adults over age 30 in the U.S. About 8.5% of them may have severe periodontitis. Gum disease is a severe infection or inflammation of ...

Mark Gurarie is a writer covering health topics, technology, music, books, and culture. He also teaches health science and research writing at George Washington University's School of Medical and ...