Methods: Patients with AO (n=45) were recruited from the orofacial pain clinics at University of Washington, Seattle, USA, Malmö University, Sweden and Aarhus University, Denmark. Inclusion criteria were >6 months pain located in a region where a tooth had been endodontically or surgically treated, with no detectable pathological cause. QST was performed at two intraoral sites (gingiva adjacent to the painful tooth/corresponding contralateral site), three times (twice on the same day by two different examiners, repeated once after 1–2 weeks by one examiner). A standardized 13-measure QST protocol, including thermal and mechanical painful and innocuous stimuli, was used. Reliability was expressed as intraclass correlation coefficient (ICC) and Cohen’s kappa (K) values.
Results: A majority of the QST measures displayed acceptable (fair or higher) reliability. Pain-site interexaminer reliability of the 12 continuous QST measures ranged from fair to excellent (ICC 0.34–0.79), and test-retest reliability from poor to good (ICC 0.04–0.72). Control-site interexaminer reliability ranged from poor to excellent (ICC 0.13–0.83), and test-retest reliability from poor to good (ICC 0.25–0.63). The single categorical QST measure had poor to fair reliability (K 0.04–0.30).
Conclusions: With few exceptions, QST performed intraorally in patients with AO had acceptable reliability, and we conclude that the method is appropriate for intraoral somatosensory assessment in pain investigations.