Trismus and pain after removal of impacted lower third molars

This study evaluated trismus and pain after removal of impacted lower third molars and investigated whether these responses were related to difficulty of surgery.

A consecutive series of 104 patients, all of whom underwent removal of an impacted lower third molar under local surgery, was studied. Difficulty of surgery was evaluated on a modified version of the Parant scale: I, extraction with forceps only; II, extraction by ostectomy; III, extraction by ostectomy and coronal section; IV, complex procedures. Trismus was evaluated in terms of maximum interincisal distance (MID) 1 and 5 days after surgery. Pain was evaluated on the basis of reported analgesic use 1 and 5 days after surgery.

Among group I subjects, mean day 1 MID did not differ significantly (P > .05) from mean presurgery MID, whereas mean day 1 MID in groups II, III, and IV was significantly lower than before surgery. In groups II, III, and IV, mean day 5 MID remained lower than before surgery. The proportion of group I patients using analgesics was significantly lower on both days 1 and 5 than the proportion of patients using analgesics in groups II, III, and IV. In all groups, the proportion of patients using analgesics dropped significantly between days 1 and 5.

Trismus is less severe after simple (forceps-only, grade I) extractions than after surgical extractions (grades II to IV). However, trismus severity after surgical extraction does not depend on difficulty of surgery. Pain, as revealed by reported analgesic use, is likewise less severe after simple extractions. Regardless of extraction type, pain declines between days 1 and 5 postsurgery.