Subjective and objective evaluation of masticatory function in patients with bimaxillary implant-supported prostheses.

BACKGROUND: People perform poorly in masticatory function tests despite well-functioning prostheses. However, it is unclear whether there is an agreement between subjective and objective measures of mastication. OBJECTIVES: To investigate the association between subjective and objective measures of masticatory function in patients with bimaxillary implant-supported prostheses. MATERIALS AND METHODS: An experimental group (n = 25, age = 70.6 ± 7.5 years, eight women) with bimaxillary implant-supported fixed prostheses and a control group (n = 25, age = 69.0 ± 5.3, 13 women) with natural dentition were recruited. The participants in the experimental group were included if they had been using the prosthesis for at least a year and had no obvious complaints with their prostheses. The control group was people with natural dentition and without any prostheses or complaints related to the masticatory system. The masticatory function was evaluated objectively with food comminution and mixing ability tests, and subjectively with jaw function limitation scale (JLFS) and oral health impact profile (OHIP). RESULTS: The experimental group performed poorly in both objective tests (p < .001). However, there was no significant differences between the two groups in total JFLS (p = .114) and OHIP (p = .312) scores. Though, there were certain positive correlations between the food comminution test and JFLS subdomains in the control group, and a positive correlation between food comminution test and specific subdomains of OHIP in the experimental group indicating poor correlation between the subjective and objective measures. CONCLUSION: Although patients with implant prostheses show poor masticatory performance, there is no agreement in the objective and subjective measures of mastication.

Effect of food hardness on chewing behavior in children.

OBJECTIVE: To investigate the effects of food hardness on chewing behavior in children compared with adults. MATERIALS AND METHODS: Healthy children (3-17 years) were equally divided into five groups based on their dental eruption stages. Each participant ate soft and hard viscoelastic test food models (3 each), while the three-dimensional jaw movements and electromyographic (EMG) activity of the bilateral masseter muscles were recorded. The data from the children were compared with a control group of healthy adults (18-35 years). The data were analyzed with nonparametric tests. RESULTS: There was no significant difference in the number of chewing cycles and the duration of the chewing sequence between children groups and adults. Children with primary dentition (3-5 years) showed shorter lateral jaw movement and higher muscle activity at the end of the chewing sequence, compared with adults. Further, children's age-groups (3-14 years) failed to adapt their jaw muscle activity to food hardness. However, at the late-permanent dentition stage (15-17 years), children were capable of performing adult-like chewing behavior. CONCLUSIONS: Overall, it seems that children as young as 3-year-old are quite competent in performing basic chewing function similar to adults. Yet, there are differences in the anticipation or adaption of jaw muscle activity and jaw kinematics to food hardness. CLINICAL RELEVANCE: The study may have clinical implication in the diagnosis and management of children with chewing impairment associated with dental malocclusions and other orofacial dysfunctions.

The antimicrobial efficacy of remote cold atmospheric plasma effluent against single and mixed bacterial biofilms of varying age.

Cold atmospheric plasma (CAP) is a minimal food processing technology of increasing interest in the food industry, as it is mild in nature compared to traditional methods (e.g. pasteurisation) and thus can maintain the food's desirable qualities. However, due to this mild nature, the potential exists for post-treatment microbial survival and/or stress adaptation. Furthermore, biofilm inactivation by CAP is underexplored and mostly studied on specific foods or on plastic/polymer surfaces. Co-culture effects, biofilm age, and innate biofilm-associated resistance could all impact CAP efficacy, while studies on real foods are limited to the food product investigated without accounting for structural complexity. The effect of a Remote and Enclosed CAP device (Fourth State Medicine Ltd) was investigated on Escherichia coli and Listeria innocua grown as planktonic cells and as single or mixed bacterial biofilms of variable age, on a biphasic viscoelastic food model of controlled rheological and structural complexity. Post-CAP viability was assessed by plate counts, cell sublethal injury was quantified using flow cytometry, and biofilms were characterised and assessed using total protein content and microscopy techniques. A greater impact of CAP on planktonic cells was observed at higher air flow rates, where the ReCAP device operates in a mode more favourable to reactive oxygen species than reactive nitrogen species. Although planktonic E. coli was more susceptible to CAP than planktonic L. innocua, the opposite was observed in biofilm form. The efficacy of CAP was reduced with increasing biofilm age. Furthermore, E. coli produced much higher protein content in both single and mixed biofilms than L. innocua. Consequently, greater survival of L. innocua in mixed biofilms was attributed to a protective effect from E. coli. These results show that biofilm susceptibility to CAP is age and bacteria dependent, and that in mixed biofilms bacteria may become less susceptible to CAP. These findings are of significance to the food industry for the development of effective food decontamination methods using CAP.