Pressure pain threshold and pain perception in temporomandibular disorder patients: is there any correlation?

Abstract

BACKGROUND AND OBJECTIVES: Physical evaluation of temporomandibular disorder patients commonly includes evaluation of pain response to muscular and articular palpation and there is a considerable uncertainty of how self-reported pain intensity relates to Pressure Pain Threshold obtained in an algometry exam. The present study aimed at determining whether pain intensity is associated to Pressure Pain Threshold in temporomandibular disorder patients. METHODS: Eighty arthralgia patients and one hundred and thirty masticatory myofascial pain patients participated in this study. Pain intensity was recorded with visual analog scale. Pressure Pain Threshold was measured using a pressure algometer. Pressure was applied bilaterally on the temporomandibular joint in arthralgia patients and masseter and anterior temporalis muscles. Pearson correlation coefficient (r) was calculated to determine the strength of the relationship between pain intensity and the lowest Pressure Pain Threshold value in each site. RESULTS: The correlation between all pain intensity and Pressure Pain Threshold values was statistically weak. Correlations between pain intensity and joint Pressure Pain Threshold (r=- 0.236; p=0.035) in the arthralgia group and pain intensity and masseter’s Pressure Pain Threshold (r=-0.312; p<0.001) and between pain intensity and anterior temporalis Pressure Pain Threshold (r=-0.240; p=0.006) were statistically significant. CONCLUSION: The weak correlation between pain intensity and Pressure Pain Threshold suggests that other factors are clearly important in explaining the pain experience of temporomandibular disorder patients, including the contribution of central nervous system nociceptive processes and psychological variables to the maintenance of chronic pain.