Abstract:

Objective

To determine the influence of different occlusal materials on the surface electromyography （sEMG） of masticatory muscles in intercuspal position and clenching status.

Methods

30 volunteers （aged 22 averagely） were selected from university students. The muscle activity of the anterior temporalis （TA） and masseter muscle （MM） were evaluated by sEMG when mandible clenches on the natural dentition （blank controlling group） and other 3 occlusal conditions with various occlusal materials in between the upper and lower jaw： articulating paper （AP）， T-Scan sensor with support（TSS） and T-Scan sensor （TS） without support. Maximum activity and asymmetry index were compared and analyzed statistically.

Results

（1）Compared with the control group， significantly higher TA and MM activity were detected within the AP， TS and TSS groups （P＜0.05）， except for the right TA of the TSS group （P＞0.05）. （2）Muscle activity between groups AP， TS and TSS showed no significant difference（P＞0.05）. （3）Compared with control group， asymmetry index of TA of AP and TSS group showed significant differences （P＜0.05）， but not in TS group （P＞0.05）； asymmetry index of MM of TSS group showed significant difference （P＜0.05）， but not in TS and AP group （P＞0.05）. （4）Compared with group TS， asymmetry index of TA showed significant differences between AP and TSS group （P＜0.05）.

Conclusions

（1）Insertion of T-Scan and articulating paper will change TA and MM muscle activity and asymmetry index in ICP maximum clench. （2）Compared with insertion of T-Scan sensor with support，insertion of T-Scan sensor without support has less effect on EMG of TA and MM in ICP maximum clench，.and therefore showed less interfere on the results of occlusal examiniation.

Key words: Masticatory muscles, Surface electromyography, T-Scan, Articulating paper, Occlusion