Intraoral Somatosensory Abnormalities in Atypical Odontalgia – A Multicenter Study

Objective: The aims of this multicenter study were to: 1. Examine intraoral somatosensory disturbances in AO patients with age- and gender-matched healthy subjects as reference material and 2. Evaluate the level of agreement between intraoral QST and QualST. 

Method: Forty-seven AO patients and 69 healthy controls were included at Universities of Washington (USA), Malmö (Sweden) and Aarhus (Denmark). In AO patients, intraoral QST and QualST were performed on the painful site, the corresponding contralateral site and at thenar. In healthy subjects, QST and QualST were performed bilaterally on the gingiva buccal to the first premolar and at thenar. Three QualST measures and 13 QST parameters were evaluated at each site. Z-scores were computed for AO patients based on the healthy reference material and LossGain scores were created.

Result: 87.3% of AO patients had QST somatosensory abnormalities compared with healthy subjects. The most frequent somatosensory absolute abnormalities found in AO patients were somatosensory gain with regard to mechanical painful stimuli and cold pain and somatosensory loss with regard to cold detection and mechanical detection. The most frequent LossGain code was L0G2 (no somatosensory loss with gain of mechanical somatosensory function) (31.9% of AO patients). Percent agreement between corresponding QST and QualST measures of thermal and/ or mechanical sensitivity ranged between 55.6 and 70.4% in AO patients and between 71.1 and 92.1% in healthy subjects.

Conclusion: Intraoral somatosensory abnormalities were very commonly detected in AO patients and agreement between quantitative and qualitative sensory testing was in the good to excellent range.