Evaluation of trismus, bite force, and pressure algometry after third molar surgery: a placebo-controlled study of ibuprofen

Abstract

Purpose: This study evaluated trismus, bite force, and pressure algometry as measures of analgesic efficacy after third molar removal.

Patients and methods: Fifty-seven patients (36 females and 21 males) developed at least moderate pain after surgical removal of a mandibular third molar and were given either ibuprofen, 400 mg (n = 26), or placebo (n = 31) in a double-blind study. Pain intensity and pain relief were rated on a five-point verbal rating scale during the 4-hour study period. Recordings of trismus, bilateral pressure pain detection and tolerance thresholds, and bite force were performed before surgery, at medication, and hourly for 4 hours. Changes in the functional variables were calculated as percent change from baseline (before surgery).

Results: The pain intensity and pain relief ratings showed significant differences between the ibuprofen- and placebo-treated patients in the 4-hour study period. The changes in trismus, bite force, and pressure pain thresholds were in accordance with these pain ratings. Pressure pain detection threshold on the operated side was significantly lower in the placebo-treated patients compared with the ibuprofen-treated patients 2 and 3 hours after medication, whereas pressure tolerance threshold showed a significant difference after 2 hours. Bite force on the operated side was significantly less reduced 3 hours after treatment with ibuprofen when compared with placebo.

Conclusions: The functional measures used support the results obtained by rating of pain intensity and pain relief, and could be of value as measures of the efficacy of an analgesic to reduce functional impairment caused by postoperative pain.