Edentulism is the clinical word for being wholly or partially toothless, or having one or more missing teeth. The loss of all teeth is called full edentulism, while the loss of only some teeth is called partial edentulism. While edentulism can be a genetic defect and takes place naturally in some species such as sloths and anteaters, this is rare and most cases of edentulism in humans is the consequences of tooth loss. A person who has one or more missing teeth is said to be edentulous or edentate. The causes of edentulism in humans are most often cavities, poor oral hygiene, gum disease, bone loss, and other periodontal issues. Teeth play an important role in appearance and health: they give the face a fuller appearance while also enabling the proper enunciation of words and syllables. Untreated edentulism can cause the chin to protrude and the cheeks to appear sunken into the face.

Edentulous/Edentulous site/Edentulous space

Edentulous simply refers to a lack of teeth; an edentulous space is an area of the mouth that no longer has (or was always missing) teeth. An edentulous patient may have only one or two missing teeth, either in one spot or throughout the mouth. An edentulous site with just a few missing teeth may be prime for a dental implant, while a fully edentulous patient may want to consider dentures. Causes of tooth loss include tooth decay, oral trauma, and advanced periodontal disease (gum disease), and an increased risk of tooth loss is noted in patients with hypertension, diabetes, poor nutrition, smoking, and arthritis. The large majority of edentulous adults are missing teeth as a result of periodontal disease; this begins with bacteria that multiplies deep underneath the gums, causing inflammation and the destruction of the bone underneath. This removes the anchor that teeth have, causing them to become loose.