The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a systematic review and meta-analysis

BACKGROUND

Xerostomia negatively affects quality of life. Symptoms include oral dryness; thirst; difficulty speaking, chewing, and swallowing food; oral discomfort; mouth soft tissue soreness and infections; and rampant tooth decay. The objective of this systematic review and meta-analysis was to investigate if gum chewing is an intervention that results in objective improvements in salivary flow rates and subjective relief from xerostomia.

METHOD

We searched electronic databases including Medline, Scopus, Web of Science, Embase, Cochrane Library (CDSR and Central), Google Scholar and the citations of review papers (last searched 31/03/23). The study populations included: 1) elderly people with xerostomia (> 60 years old, any gender, and severity of xerostomia), and 2) medically compromised people with xerostomia. The intervention of interest was gum chewing. Comparisons included gum chewing vs. no gum chewing. The outcomes included salivary flow rate, self-reported xerostomia, and thirst. All settings and study designs were included. We conducted a meta-analysis on studies where measurements of unstimulated whole salivary flow rate for both a gum chewing, and no gum chewing intervention (daily chewing of gum for two weeks or longer) were reported. We assessed risk of bias using Cochrane's RoB 2 and ROBINS-I tools.

RESULTS

Nine thousand six hundred and two studies were screened and 0.26% (n = 25) met the inclusion criteria for the systematic review. Two of the 25 papers had a high overall risk of bias. Of the 25 papers selected for the systematic review, six met the criteria to be included in the meta-analysis which confirmed a significant overall effect of gum on saliva flow outcomes compared to control (SMD = 0.44, 95% CI: 0.22-0.66; p = 0.00008; I² = 46.53%).

CONCLUSIONS

Chewing gum can increase unstimulated salivary flow rate in elderly and medically compromised people with xerostomia. Increasing the number of days over which gum is chewed increases the improvement in the rate of salivation. Gum chewing is linked with improvements in self-reported levels of xerostomia (although it is noted that no significant effects were detected in five of the studies reviewed). Future studies should eliminate sources of bias, standardise methods to measure salivary flow rate, and use a common instrument to measure subjective relief from xerostomia.

STUDY REGISTRATION

PROSPERO CRD42021254485.

Review of paediatric gastrointestinal physiology relevant to the absorption of orally administered medicines

Despite much progress in regulations to improve paediatric drug development, there remains a significant need to develop better medications for children. For the design of oral dosage forms, a detailed understanding of the specific gastrointestinal (GI) conditions in children of different age categories and how they differ from GI conditions in adults is essential. Several review articles have been published addressing the ontogeny of GI characteristics, including luminal conditions in the GI tract of children. However, the data reported in most of these reviews are of limited quality because (1) information was cited from very old publications and sometimes low quality sources, (2) data gaps in the original data were filled with textbook knowledge, (3) data obtained on healthy and sick children were mixed, (4) average data obtained on groups of patients were mixed with data obtained on individual patients, and (5) results obtained using investigative techniques that may have altered the outcome of the respective studies were considered. Consequently, many of these reviews draw conclusions that may be incorrect. The aim of the present review was to provide a comprehensive and updated overview of the available original data on the ontogeny of GI luminal conditions relevant to oral drug absorption in the paediatric population. To this end, the PubMed and Web of Science metadatabases were searched for appropriate studies that examined age-related conditions in the oral cavity, esophagus, stomach, small intestine, and colon. Maturation was observed for several GI parameters, and corresponding data sets were identified for each paediatric age group. However, it also became clear that the ontogeny of several GI traits in the paediatric population is not yet known. The review article provides a robust and valuable data set for the development of paediatric in vitro and in silico biopharmaceutical tools to support the development of age-appropriate dosage forms. In addition, it provides important information on existing data gaps and should provide impetus for further systematic and well-designed in vivo studies on GI physiology in children of specific age groups in order to close existing knowledge gaps and to sustainably improve oral drug therapy in children.

Association between anorexia and hyposalivation in community-dwelling older adults in Japan: a 6-year longitudinal study

BACKGROUND

Hyposalivation is associated with the nutritional status. Anorexia of ageing, defined as an age-related decrease in appetite and food intake, presents even in healthy adults and is considered an independent predictor of malnutrition, frailty, and mortality. However, the relationship between anorexia and hyposalivation of ageing is unclear. Thus, the present longitudinal study aimed to investigate the incidence of hyposalivation and its relationship with anorexia in community-dwelling older people in Japan.

METHODS

The study population comprised 220 individuals (80 men and 140 women) aged 65-86 years at baseline. The participants underwent comprehensive health check-ups, including dental examinations and anthropometry, and face-to-face interviews in 2013 and 2019. Hyposalivation was determined on the basis of the unstimulated salivary flow rate measured using the modified cotton roll method. Anorexia was defined as a score of ≤29 in the Japanese version of the Council on Nutrition Appetite Questionnaire. Logistic regression analyses were used to test whether the presence of anorexia at baseline was an independent predictor of hyposalivation.

RESULTS

Hyposalivation developed at a rate of 19.5% during the 6-year observation period. Anorexia was observed in 95 (43.2%) participants at baseline. After adjusting for potential confounding factors, anorexia (adjusted odds ratio [AOR], 2.65; 95% confidence interval [CI], 1.26-5.57) and polypharmacy (AOR, 3.29; CI, 1.06-10.19) were significant predictors of hyposalivation.

CONCLUSION

Loss of appetite is independently correlated with and a risk factor for hyposalivation in older adults. Anorexia of ageing may have negative effects on the salivary flow rate in such settings. Salivation should be a standard feature in clinical assessments of the older adults.

Caries reporting in studies that used the International Caries Detection and Assessment System: A scoping review

OBJECTIVE

To explore how caries was reported in studies that employed the International Caries Detection and Assessment System (ICDAS).

METHODS

A systematic database search up to August 2017 was carried out using PubMed, Ovid MEDLINE, Cochrane library and ISI Web of Science electronic databases. Only studies that used the ICDAS for dental caries examinations were included. Studies were excluded if the examination was done only for the validation or the calibration of the ICDAS and/or if the examination was not done for the whole dentition. Measures used to report caries were considered.

RESULTS

A total of 126 papers met the inclusion criteria. Forty-four different synthesis measures were used to report caries. Most of the studies used a combination of multiple measures to report patient's caries level. These reporting measures cluster into four main groups: the number of individual ICDAS scores (ie, total counts of every score); the number of decayed surfaces/teeth (ie, total counts of combined caries scores for surfaces or teeth); measures of caries experience (ie, total counts of combined caries scores, filled and/or missing surfaces or teeth); and measures of central tendency and dispersion. The number of decayed surfaces and individual ICDAS scores were the most commonly used measures. Three studies used mean ICDAS score (ie, total ICDAS scores divided by the number of teeth), two used mean ICDAS score of carious teeth (ie, total ICDAS scores divided by the number of carious teeth) and two used the maximum ICDAS score (ie, highest ICDAS score recorded). The total ICDAS score was used only once. Many studies synthesized from the ICDAS the number of decayed, missing and filled teeth/surfaces (dmft/DMFT, dmfs/DMFS) as a measure of caries experience.

CONCLUSIONS

There are variations among studies in the utilization of the system to summarize caries. Most studies presented caries data using the categorical characteristics of the ICDAS.

Salivary sCD14 as a potential biomarker of dental caries activity in adults

CD14 is a co-receptor involved in the recognition of Gram-negative and Gram-positive bacteria, the latter known to cause dental caries. The aim of this study was to determine whether soluble CD14 (sCD14) in saliva was associated with caries activity and the collection method from the saliva. The study included 55 participants aged 20 to 40 years, 30 with dental caries and 25 caries-free controls. We collected 110 saliva samples in total, 55 of resting saliva and 55 of mechanically stimulated saliva. Median levels of sCD14, measured with a matrix-matched enzyme-linked immunosorbent assay (ELISA), were higher in the caries-active than in the caries-free group in either resting (203.3 vs.167.9 ng mL-1; P<0.01) or stimulated saliva (201 vs.105.7 ng mL-1; P<0.01). The resting salivary flow rate was lower in the caries-active than caries-free group (0.61±0.42 vs. 0.98±0.52 mL min-1; P<0.01). Hyposalivation was observed only in the caries-active group (10 and 13 % in stimulated and resting saliva, respectively). Higher salivary sCD14 levels and secretion rates were clearly associated with dental caries and resting saliva. Future studies should focus on the clinical utility of salivary sCD14 as a potential biomarker and predictor of future caries events.

A pilot study on the feasibility of training nurses to formulate multicomponent oral health interventions in a residential aged care facility

OBJECTIVES

This 10 weeks feasibility study investigated whether residential care nurses with 12 hours advanced oral health training in assessments and saliva testing could formulate, implement and monitor individualised oral care plans of early dementia residents.

METHOD

Four trained lead advocate nurses using SXI-D, OHIP14, oral health assessment tool (OHAT) assessments and a modified saliva test formulated nurse scheduled comprehensive oral care plans (NSCOCPs) by selecting and scheduling preventive products and procedures multiple times throughout the day to alkalise the mouth of 8 residents as an adjunct to assisted brushing and high-fluoride toothpaste.

RESULTS

Nurse assessments, saliva tests and care plans were validated against oral health therapist (OHT) findings. Care plan agreement between Nurse and OHT intervention selection and scheduling was high (75%-88%). Untrained nurse compliance was very high, 86%-99% for the 4930 scheduled interventions. Untrained nurses delivered multiple scheduled interventions by following NSCOCPs despite initially not understanding the reason for each of 9 interventions categories. NSCOCPs could track and monitor whether a recommended intervention had been completed by general nursing staff over 3 nursing shifts.

CONCLUSION

The role of nurses may have to be expanded beyond traditional roles to meet the growth and changes in oral health needs in residential facilities. Intensive training of a few lead advocate nurses to assess risk and formulate individualised NSCOCPs provides a method to transfer knowledge to untrained staff and deliver multicomponent preventive interventions soon after entry into residential care where timely visits by dental professionals to examine residents and prescribe preventive interventions are infrequent or unlikely.

Supplementation of xylitol-containing chewing gum with probiotics: a double blind, randomised pilot study focusing on saliva flow and saliva properties

The aim of this study was to investigate the impact of daily chewing, for 12 weeks, of 2 different probiotic gums compared with placebo on saliva flow rate, saliva IgA levels and saliva pH.

Salivary Parameters (Salivary Flow, pH and Buffering Capacity) in Stimulated Saliva of Mexican Elders 60 Years Old and Older

OBJECTIVE

To compare a limited array of chewing-stimulated saliva features (salivary flow, pH and buffer capacity) in a sample of elderly Mexicans with clinical, sociodemographic and socio-economic variables.

SUBJECTS AND METHODS

A cross-sectional study was carried out in 139 adults, 60 years old and older, from two retirement homes and a senior day care centre in the city of Pachuca, Mexico. Sociodemographic, socio-economic and behavioural variables were collected through a questionnaire. A trained and standardized examiner obtained the oral clinical variables. Chewing-stimulated saliva (paraffin method) was collected and the salivary flow rate, pH and buffer capacity were measured. The analysis was performed using non-parametric tests in Stata 9.0.

RESULTS

Mean age was 79.1 ± 9.8 years. Most of the subjects included were women (69.1%). Mean chewing-stimulated salivary flow was 0.75 ± 0.80 mL/minute, and the pH and buffer capacity were 7.88 ± 0.83 and 4.20 ± 1.24, respectively. Mean chewing-stimulated salivary flow varied (p < 0.05) across type of retirement home, tooth brushing frequency, number of missing teeth and use of dental prostheses. pH varied across the type of retirement home (p < 0.05) and marginally by age (p = 0.087); buffer capacity (p < 0.05) varied across type of retirement home, tobacco consumption and the number of missing teeth.

CONCLUSIONS

These exploratory data add to the body of knowledge with regard to chewing-stimulated salivary features (salivary flow rate, pH and buffer capacity) and outline the variability of those features across selected sociodemographic, socio-economic and behavioural variables in a group of Mexican elders.