Effect of Dental Rehabilitation on Masticatory Function Following Jaw Reconstruction

Purpose: This study examined the effect of dental implant rehabilitation on masticatory function following jaw reconstruction. Materials and Methods: Patients who received dental rehabilitation after jaw reconstruction with a fibular or iliac bone flap from 2012 to 2018 were examined for masticatory efficiency, electromyographic (EMG) activity of the masticatory muscles, and the distribution of occlusal force. The masticatory efficiency was measured by a spectrophotometer. The asymmetry index of the masticatory muscle was calculated by EMG measurement, and the asymmetry index of the occlusal force was calculated by T-scan analysis. Results: A total of 32 patients were examined, 13 with implant-retained fixed dental prostheses, 9 with implant-retained removable dental prostheses, and 10 with removable dental prostheses. Masticatory efficiency was significantly lower in the removable dental prosthesis group (2.29 +/- 0.19) than in the implant-retained removable dental prosthesis (2.45 +/- 0.03, P < .05) and implant-retained fixed dental prosthesis groups (2.45 +/- 0.03, P < .05). Moreover, the asymmetry index of the masticatory muscle while chewing and clenching was significantly higher in the removable dental prosthesis group (0.099 +/- 0.046 and 0.107 +/- 0.042, respectively) than in the implant-retained removable dental prosthesis (0.032 +/- 0.019 and 0.035 +/- 0.021, respectively; P < .01) and implant-retained fixed dental prosthesis groups (0.038 +/- 0.021 and 0.046 +/- 0.023, respectively; P < .01). The asymmetry index of the occlusal force was also significantly higher in the removable dental prosthesis group than in the implant-retained removable dental prosthesis (0.38 +/- 0.08, P < .01) and implant-retained fixed dental prosthesis groups (0.36 +/- 0.11, P < .05). Conclusion: The results of this study suggest that dental implant prostheses have a greater effect on masticatory function following jaw reconstruction, improving masticatory efficiency, EMG activity of the masticatory muscles, and occlusal force.