Contraindications for removal of impacted teeth

All impacted teeth should be removed unless specific contraindications justify leaving them in position. When the potential benefits outweight the potential complications and risks, the procedure should be performed. Similarly, when the risks are greater than the potential benefits, the procedure should be deferred. Contraindications for the removal impacted teeth primarily involve the patient's physical status.

Extremes of age

The third molar tooth bud can be seen radiographically by age 6. Some surgeons think that removal of the tooth bud at age 7 to 9 can be accomplished with minimal surgical morbidity and therefore shoud be performed at this age. However, most surgeons believe that it is not possible to predict accurately if the forming third molar will be impacted. The consensus is that very early removal of third molars should be deferred until an accurate diagnosis of impaction can be made.

The most common contraindication for the removal of impacted teeth is advanced age. As a patient ages, the bone becomes highly calcified and therefore less flexible and less likely to bend under the forces of tooth extraction. The result is that more bone must be surgically removed to displace the tooth from its socket.

Similarly, as patients age, they respond less favorably and with more postoperative sequelae. An 18-year-old patient may have 1 or 2 days of discomport and swelling after the removal of an impacted tooth, whereas a similar procedure may result in a 4 or 5 days recovery period for a 50-year-old patient.

In an older patient (usually over age 40) with an impacted tooth that shows no signs of disease and that has a layer of overlying bone (usually at least 4 mm) the tooth should not be removed. The dentist caring for the patient should check the impacted tooth radiographically every 1 or 2 years to ensure that no adverse sequela occurs.

If the impacted tooth shows signs of cystic formation or periodontal disease involving either the adjacent tooth or the impacted tooth, if it is a single impacted tooth underneath a prosthesis with thin overlying bone, or if it becomes symptomatic as the result of infection, the tooth must be removed.

Compromised medical status

Similar to extremes of age, compromised medical status contraindicates the removal of an impacted tooth. Frequently, compromised medical status and advancing age go hand-in-hand. If the impacted tooth is asymptomatic, its surgical removal must be viewed as elective. If the patient's cardiovascular or respiratory function or host defenses for combating infection are compromised or if the patient has a serious acquired or congenital coagulopathy, the surgeon must consider living the tooth in the alveolar process. On the other hand, if the tooth becomes symptomatic, the surgeon must work carefully with the patient's physician to remove the tooth with the least operative and postoperative medical sequelae.

Probable excessive damage to adjacent structures

If the impacted tooth lies in an area in which its removal may seriously jeopardize adjacent nerves, teeth, or previously constructed bridges, it may be prudent to leave the tooth in place. When the dentist makes the decision not to remove a tooth, the reasons must be weighed against potential future complications. For younger patients who may suffer the sequelae of impacted teeth, it may be wise to remove the tooth while taking special measures to prevent damage to adjacent structures.
However, for the older patient with no signs of impending complications and for whom the probability of such complications is low, the impacted tooth should not be removed. A classic example of such a case is the elderly patient with a potentially severe periodontal defect on the distal aspect of the second molar but in whom removal of the third molar would almost surely result in the loss of the second molar. In this situation the impacted tooth should not be removed.