An investigation of the rationality of lower third molar removal, based on USA National Institutes of Health criteria

Abstract

The appropriateness of surgical removal of lower third molars was audited in relation to 500 consecutive patients referred to hospital for third molar management during 1993/4. The National Institutes of Health (NIH) criteria were used as the validating standard. Immediately after patients had been seen for treatment planning, research workers repeated history taking and clinical examination and recorded the treatment that was planned. Appropriateness of treatment planning was then assessed. A total of 95% of patients had bilateral and 5% had unilateral lower third molars (976 teeth in all); 69% were partially erupted, 35% unerupted and 5% fully erupted. There was a weak correlation between eruption status of bilateral third molars. The most frequent reason for removal of third molars (31%) was pericoronitis, though the next most frequent reason was that the contralateral tooth had been scheduled for removal under general anaesthesia. Allowing this as a legitimate reason for surgery, of 859 teeth scheduled for removal, 59% were justified according to NIH criteria. Some 169 (34%) of patients might have avoided surgery altogether if NIH criteria had been the basis for intervention and a further 147 (30%) could have been scheduled for removal of only one lower third molar. These findings suggest that criteria for removal other than NIH criteria are being applied. Further research is necessary to identify these.