Influence of chronic stress and chewing over pain.

Introduction: Chronic stress and mastication affect the response to pain; however, there is little knowledge about the relationship between these variables. Objective: Determine the influence of chronic stress and mastication on the response to pain. Methods: thirty-two 8-week-old male Balb/c mice were used. The sample was divided into 4 equal groups: Group N: normal mastication without stress; Group NE: Normal chewing + stress, Group D: deficient chewing without stress and Group DE: Poor chewing + stress. The response to the painful stimulus was evaluated through the tail withdrawal assay due to a thermal stimulus. Results: By comparing the 4 experimental groups to the fourth and the eighth week through the ANOVA test yielded a value of p = 0.982 and p = 0.176; respectively. By applying the ‘t’ student, within each group, in comparison of the variation of the pain response between the fourth and eighth week, the values of p = 0.52; p = 0.17; p = 0.84 and p = 0.069 were obtained for the group N, NE, D and DE respectively. Conclusion: Chronic stress and mastication do not modify the response to pain in albino Balb/c mice.