Mouth

Mouth entrance to the digestive and respiratory tracts. The mouth, or oral cavity, is ordinarily a simple opening in lower animals; in vertebrates it is a more complex structure. In humans, the mouth is defined in front and at the sides by the lips, jawbone, teeth, and gums; in the rear it merges with the throat. The roof of the mouth is composed of the hard and soft palates and the floor of the mouth is formed by the tongue, a muscular structure that contains the organs of taste (taste buds).

Periodontitis

Periodontitis is a serious gum infection that destroys the soft tissue and bone that support your teeth. Periodontitis can cause tooth loss or worse, an increased risk of heart attack or stroke and other serious health problems.
Periodontitis is common but largely preventable. Periodontitis is usually the result of poor oral hygiene. Daily brushing and flossing and regular professional dental cleanings can greatly reduce your chance of developing periodontitis.