Judgement on removal of asymptomatic mandibular third molars: influence of the perceived likelihood of pathology.

Thirty general dental practitioners and 10 oral surgeons were asked to judge the need for removal of 36 asymptomatic impacted third molars. To estimate the reliability of the judgement, the 36 cases were duplicated. The participants had to estimate the strength of the indication for extraction and, if the teeth were not extracted, the probability of development of pathology in general and of six specific complications on a Visual Analogue Scale. Multiple linear regression analysis was used to describe their judgement. There was a high correlation between the indication index for extraction and the perceived likelihood of the development of pathology, although there was considerable individual variation. The general dental practitioners rated cyst development as the most, and pericoronitis as the second most, influential factors in their decision to extract the third molar. The oral surgeons rated pericoronitis the highest and the development of a cyst or caries in the second molar as the second highest factors influencing their judgement. Tumour formation and root resorption received low weightings. Intraexaminer reliability was high. The study confirms that the judgement to extract asymptomatic impacted third molars is not made solely on the basis of cognitive factors.