Masticatory functional analysis after replacing multiple missing teeth with implant-supported single crowns – A prospective cohort study

AIMS: To study the outcome of the function after replacing multiple missing teeth with single screw retained crowns. SETTINGS AND DESIGN: A Prospective cohort study was planned to determine the importance of masticatory functional improvements. OBJECTIVE: Objective of this study was to evaluate the changes in masticatory timing, movements, and muscle function resulting from replacing multiple missing teeth with implant-supported crowns. MATERIALS AND METHODS: Thirty prospective patients having multiple teeth missing went through Bite force, EMG functional activity, and masticatory incisor-point movements recording during chewing of gum and of hard food before and after replacing the missing teeth with implant-supported crowns. Disclusion Time Reduction (DTR) occlusal therapy was applied to each case after placement. The results obtained were statistically evaluated for significance using Wilcoxon signed-rank test and Student's t-test alpha = 0.05. STATISTICAL ANALYSIS USED: The Wilcoxon Signed-Rank test was used to analyze the kinematics and Student's t test the muscle activities. RESULTS: For left-sided and right-sided gum-chewing, the group mean values of 4 and 5 quantified parameters calculated from the average chewing pattern were found to have significantly improved toward more normal values (P < 0.05). Same with Hard-bolus chewing group, mean values of 8 and 6 quantified parameters calculated from the Average Chewing Pattern (ACP) were found to have significantly improved towards more normal values (P < 0.05). Same with Hard-bolus chewing group, mean values of 8 and 6 quantified parameters calculated from the Average Chewing Pattern (ACP) were found to have significantly improved towards more normal values (p < 0.05). Multiple EMG average chewing cycle muscle activity patterns also improved significantly (P < 0.05). The mean disclusion time of the group was significantly reduced (P < 0.00000) as was the mean EMG muscle activity during lateral excursions (P < 0.000002). CONCLUSIONS: Measurable significant improvements in mean masticatory functional movements and associated muscle activity during gum-chewing were recorded after the placement of the implant-supported crowns followed with DTR therapy to optimize the occlusions. Additional significant changes were seen when the subjects masticated a challenging hard bolus. Mean muscle effort during left and right lateral excursions was also significantly reduced.