Effect of clinical guidelines on practice for extraction of lower third molars: study of referrals in 1997 and 2000.

We made a retrospective study of patient records for 3-month periods during 1997 and 2000 to assess changes in referral patterns and decision-making for extraction of lower third molars after publication of national guidelines. A total of 277 patients were referred to the department for extraction of lower third molars in 1997 and 234 in 2000 while overall referrals increased from 884 to 979. The number having extractions dropped from 243/277 (88%) to 190/234 (81%) of those referred (P=0.05) and of those operated on, bilateral removal dropped from 120/243 (49%) to 65/190 (34%) (P=0.002). The number of patients operated on under general anaesthesia reduced from 161/243 (66%) to 103/190 (54%) (P=0.01). However, women remained more likely to get treatment under general anaesthesia than men. In conclusion, there was a reduction in referrals for extraction of third molars, the proportion of referred patients having extractions, the number of bilateral operations, and changes in the choice of anaesthesia over the period of introduction of national guidelines on operations for third molars.