Neutral zone (dentistry)

In dentistry (particularly prosthodontics and to a lesser extent orthodontics), the neutral zone refers to that space in the oral cavity where the forces exerted by the musculature of the tongue are equal and balanced with the forces exerted by the buccinator muscle of the cheek laterally and the orbicularis oris muscle anteriorly.^[1][2] The neutral zone generally determines the horizontal location of teeth. Teeth are guided into the neutral zone as they erupt into the mouth during childhood development.

The neutral zone is an important concept in prosthodontics, because prosthetic teeth generally must conform to the horizontal position determined by the neutral zone. Prostheses which set teeth outside this zone risk problems such as discomfort, cheek or tongue biting, and instability of the denture.

The neutral zone is also important in orthodontics. Moving teeth outside of this zone means that the muscular forces on the teeth will be out of balance in one direction, and tend to be more likely to relapse to their original position.

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