Oral health is defined as a condition free from chronic mouth / facial pain. The list goes on. Enjoying good oral health includes being free from often fatal diseases such as mouth and throat cancer. We even count birth defects for example cleft lip or palate within the category of oral health.
Gum issues, tooth decay including the loss of a tooth or teeth are further examples what constitutes bad oral health. Habits which contribute to adverse oral health are: unhealthy eating habits (junk food), smoking, the use of alcohol even in small quantities, and bad or nonexistent oral hygiene.