Signs and symptoms of toothlessness
- Support the lips and cheeks, providing for a fuller, more aesthetically pleasing appearance
- Maintain an individual's vertical dimension of occlusion
- Allow for the proper pronunciation of various sounds, along with the tongue and lips
- Preserve and maintain the height of the alveolar ridge
- Cut, grind, and otherwise chew food

Facial support and aesthetics
- The absence of teeth causes the cheeks to exhibit a sunken-in appearance and wrinkle lines to form at the commissures
- The anterior teeth support the lips and provide certain aesthetic features, such as an acute nasiolabial angle
- Loss of muscle tone and skin elasticity due to old age exacerbates the sunken-in appearance
- The tongue tends to broaden out in the absence of teeth, making it difficult to fabricate dentures
- Prosthetic teeth help restore the natural appearance of the mouth and support the lips

Vertical dimension of occlusion
- The loss of teeth leads to a decrease in the vertical dimension of occlusion
- Without teeth, the mouth tends to overclose, causing a sunken-in appearance of the cheeks
- Overclosure may result in altered tone and elasticity of the mandible and TMJ
- The excessive cheek than needed contributes to the sunken-in appearance
- Treating the overclosure is essential to maintain the proper vertical dimension of occlusion

Pronunciation
- Teeth play a major role in speech, allowing proper pronunciation of certain sounds
- Consonant sounds like 't,' 'd,' 's,' 'z,' 'f,' and 'v' require tooth-to-tooth contact
- Sounds like 't,' 'd,' 's,' 'z,' 'f,' and 'v' require tongue-to-tooth contact
- Fricatives like 'f' and 'v' are achieved through lip-to-tooth contact
- Edentulous individuals find it difficult to enunciate these sounds properly

Preservation of alveolar ridge height
- Alveolar ridges are columns of bone that surround and anchor the teeth
- When teeth are absent, the alveolar bone slowly resorbs
- Resorption occurs in the vertical, anterioposterior, and faciolingual dimensions
- Pressure on the bone exacerbates resorption, affecting ridge width
- Retaining tooth roots or using implants can help decrease bone loss and maintain ridge shape