Impacted Third Molar Teeth: Remove or Observe and When?

There is a long history of debate over the need to remove third molar teeth which are impacted but asymptomatic. Recently I read a study from Finland which suggested third molar teeth are often times removed prematurely. This is in sharp contrast to the West Coast, more common, practice of the removal of impacted third molar teeth at younger ages (ages 14-18).

The study performed in Finland consisted of 81 university student patients who underwent an examination and panoramic radiographs. Based upon the initial results, an oral surgeon estimated the likelihood of the patient needing to undergo third molar tooth removal within the next five years. Indications for surgery included teeth which were unerupted and presumed to remain impacted and teeth that were unerupted and presumed to erupt in a nonfunctional position.

A 12 year follow-up of the original group provided the following information:

135 teeth (47%) had been removed
115 teeth (40%) had erupted
35 teeth (12%) remain unerupted or partially erupted

It had initially been predicted that 75% of all patients would need one or more third molar teeth removed with-in the next five years and only 59% of the predicted number actually had been removed. The study argues against the routine removal of third molar teeth in adults. If this study is clinically relevant, why are many oral and maxillofacial surgeons (myself included) recommending the removal of impacted third molar teeth at younger ages in direct opposition to this study?

The answers are as follows:

1. The study does NOT take into consideration the degree of difficulty of the surgery to the patient as the patient ages.
2. The study does NOT take into consideration the sharp increase in surgical risks and complications including permanent nerve involvement in the older patient.
3. The study does NOT take into consideration the likelihood of increased medical problems associated with the older patient.
4. The study does NOT take into consideration the increase in length of recovery from the surgery.
5. The study does NOT take into consideration the possibility of periodontal disease, root canal treated teeth, crowned teeth, 3-unit bridges or dental implants adjacent to the surgical field which are more common in the middle aged patient than in the patient group of ages 20-32.