Long-lasting Mechanical Sensitization Following Third Molar Surgery

Aims: To investigate the degree and duration of neuronal hyperexcitability due to local inflammatory trauma after surgical removal of an impacted mandibular third molar. Methods: A total of 32 healthy men (16 patients, 16 control subjects) underwent quantitative sensory tests (QST) at baseline (preoperatively) and 2, 7, and 30 days following surgical removal of a mandibular third molar. Thermal and mechanical QST was applied to the extraoral and intraoral regions as well as to the dominant forearm. Results: Detection thresholds for thermal and mechanical stimuli did not change over time in patients and control subjects, but pain thresholds (thermal, pressure, electrical) in the control group increased significantly. Patients showed significantly decreased pain pressure thresholds and pressure pain tolerance (P .05 for both) on the operated side and absence of adaptation to the tests for up to 30 days postoperatively. Conclusion: These results indicate that even a minor surgical procedure in the orofacial region may be sufficient to evoke hyperexcitability in an area adjacent to the surgical wound for up to 30 days. The decreased adaptive capacity in the patient group also suggests the involvement of central pain-regulatory mechanisms in response to the surgical trauma. Keywords: orofacial, pressure pain, sensitization, third molar