Clinical interventions to improve masticatory performance of extensive removable denture wearers and stroke survivors

Abstract

This thesis includes three systematic reviews and two clinical trials, all of which are related to the masticatory function of older adults.

Chapter 2 (systematic review and meta-analysis) and Chapter 3 (clinical trial) aim to study the effectiveness of denture adhesives and explore their usage in extensive partial denture (EPD) wearers. The systematic review analysed 39 studies on the use of denture adhesives for complete denture wearers. Results of the meta-analysis indicated that denture adhesives provided significantly higher retention for complete dentures, and therefore improved the maximum bite force and masticatory performance of the complete denture wearers. The corresponding clinical trial is 3-month self-controlled study investigating the effect of a commercial cream adhesive on EPD wearers. A total of 105 EPD wearers (52 wore one EPD and 53 wore two EPDs) were recruited at the baseline, and 83 completed the whole study. The results showed that most EPD wearers experienced pronounced improvement in denture retention and stability after using denture adhesives. Their maximum bite force and masticatory performance also showed persistent improvement. The study also found that EPD wearers with problematic or metal-based dentures and those wearing two EPDs benefited more from using denture adhesives. Furthermore, self-assessed masticatory function and oral health-related quality of life of the participants significantly improved after using denture adhesives. In conclusion, denture adhesives can improve the retention and stability of the EPDs, thereby improving the masticatory performance of EPD wearers.

Chapter 4 and Chapter 5, systematic reviews and meta-analyses, are both related to the clinical trial described in Chapter 6. Chapter 4 showed that while oral exercises significantly improved the maximum bite force of the study participants, there was no significant improvement in their masticatory performance. Among the three types of oral exercises, chewing exercise was found to be the most effective, followed by clenching exercise, while simple oral exercise had little effect. Chapter 5 summarised the current research on the masticatory performance of stroke patients and it was found that comparing to age-matched healthy individuals, stroke patients had significantly lower maximum bite force and masticatory performance, with masticatory performance being the most affected. Thus, a corresponding clinical trial was conducted which aimed to investigate the effects of performing oral exercises that consisted of masticatory exercise and active range of motion exercise on the masticatory function, nutritional intake, and general health conditions of stroke patients undergoing rehabilitation. The preliminary results from 40 completed cases indicated that oral exercises improved the masticatory performance and posterior bite force of stroke survivors. They also increased the extent of protrusive and lateral movement of the mandible while maintaining the degree of maximum mouth opening. However, oral function only plays a small role in the overall stroke rehabilitation, and it has little influence on their nutritional intake and general health conditions.