Importance of Standardized Palpation of the Human Temporomandibular Joint

To test whether standardized palpation around the lateral pole of the condyle can influence mechanical sensitivity and unpleasantness and evoke referred sensations/pain in healthy individuals.

Palpometers (0.5, 1.0, and 2.0 kg) with spherical extensions were applied around the lateral pole of the condyle in relaxed and protruded positions of the mandible for 2, 5, and 10 seconds in 30 healthy participants. Mechanical sensitivity, unpleasantness, and referred sensations/pain were assessed using a 0 to 100 numeric rating scale (NRS) for each palpation. The NRS scores were compared using analysis of variance and McNemar test.

Participants reported significantly higher mechanical sensitivity and unpleasantness scores for the 2.0-kg stimulus compared to the 0.5- and 1.0-kg stimuli for 2, 5, and 10 seconds (mean NRS > 50; P < .001). Application of a 1.0-kg stimulus was significantly different from the 0.5- and 2.0-kg stimuli applied for 5 seconds (mean NRS < 50; P < .001). One-third of participants reported referred sensations/pain.

Application of a 2.0-kg stimulus around the lateral pole of the condyle is painful and unpleasant regardless of time of palpation. Application of a 1.0-kg stimulus for 5 seconds was found to be nonpainful and not unpleasant in healthy participants. Thus, this study supports the Diagnostic Criteria for TMD recommendation for standardized examination of the TMJ and indicates that referred sensation/pain is a common finding in healthy individuals.