Edentulism is used to describe an area of missing teeth.  Edentulism may be partial (missing one or some teeth) or complete (missing all teeth).  

Dentures are a removable option used to treat edentulous spaces, or replace missing teeth.  A complete denture is needed when all of the teeth are missing in one or both jaws (fully edentulous).  A partial denture is used to replace one to several teeth when there are still natural teeth to anchor it to (partially edentulous).  

Tooth replacement options depend on an individualized assessment, the health of neighboring teeth, the way the bite fits together (occlusion), and the time and resources a patient wishes to devote to the procedures and appliances. Some are “fixed,” meaning they stay in the mouth, while others are “removable” and are removed at bedtime. Whenever possible, a fixed option is preferred because it feels and looks more natural and comfortable.