• Xuejiao Li, Ye Cao, and Qiufei Xie.
• Department of Prosthodontics, Center for Oral and Jaw Functional Diagnosis, Treatment and Research, Peking University School and Hospital of Stomatology, Beijing 100081, China.
• Zhonghua Kou Qiang Yi Xue Za Zhi. 2014 Oct 1;49(10):596-9.

ObjectiveTo investigate the relationship between the existence of occlusal interference and masticatory muscle hyperalgesia by exploring the stimulus-response relationship between the duration of occlusal interference and masticatory muscle mechanical withdrawal threshold.MethodsOcclusal interference with 0.4 mm-thick crowns on rat molars was removed under anaesthesia at 2, 3, 4, 5, and 6 d after wear, and masticatory muscle mechanical withdrawal threshold was tested at 1, 3, 5, 7, 10, 14, 21 and 28 d.ResultsDecreased mechanical withdrawal thresholds were detected in temporal muscles and masseter muscles on both sides following occlusal interference (P < 0.05). After removal of crowns at 2, 3, 4 and 5 d, rats exhibited the similar head withdrawal thresholds as the sham-application control in masticatory muscles on both sides at 10, 14, 14 and 21 d (P > 0.05). No significant differences were detected between the contralateral side with the ipsilateral side (P < 0.05). After removal of crowns at 6 d, rats still exhibited significantly decreased head withdrawal thresholds[right temporal muscle: (1.365±0.018) N; right masseter: (1.437 ± 0.024) N] in masticatory muscles on both sides until the last day of the experiment[the sham-application control: right temporal muscle: (1.554±0.040) N, P < 0.001; right masseter: (1.546±0.019) N, P < 0.001].ConclusionsThe mechanical hyperalgesia can disappear after removal of the occlusal interference at 5 d, and the existence of the occlusal interference is positively correlated with the duration of the mechanical hyperalgesia.

10 keywords...

hide…