Coronectomy to prevent damage to the inferior alveolar nerve.

Conventional wisdom advises that when a tooth needs to be extracted, the whole tooth should be removed, usually with as little surrounding bone as possible. However, the evidence to support this is not compelling, and every dentist has experienced cases where the apices of teeth are not removed for a variety of reasons and, in most cases, the patient seems to suffer no ill effects. If one extrapolates from this, it is evident that there might be instances where it is actually preferable to leave the apical part of the root rather than remove it, and this can be carried out deliberately. The usual time that one would consider this is when the inferior alveolar nerve is intimately related to the roots of the lower molar teeth, and this occurs most often in relation to the third molar. This concept of deliberately removing only the crown and part of the root of the tooth is known variously as coronectomy, partial root removal, deliberate vital root retention, or partial odontectomy.