Non-Cochrane · intervention · PM37340436
The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a systematic review and meta-analysis.
Dodds Michael W J, Haddou Mohamed Ben, Day Jon E L · BMC oral health · 2023 · PubMed · doi:10.1186/s12903-023-03084-x
Full textEvery question was extracted from the full text, figures and supplements by two independent LLM extractors, disagreements adjudicated. Rows cite where in the review the value comes from.
Questions
6
current version
GRADE rated
0
No studies
0
Included studies
26
linked below
No studies 0 · 0%Ungraded 6 · 100%Very low 0 · 0%Low 0 · 0%Moderate 0 · 0%High 0 · 0%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | 1) Elderly people with xerostomia (>60 years old, any gender, any severity); 2) medically compromised people with xerostomia; no geographic restriction | Elderly and medically compromised adults with xerostomia / dry mouth (haemodialysis, cancer / radiotherapy, chronic heart failure, rheumatic disease, palliative care, community-dwelling and institutionalised older adults) (n=25 studies) |
| Intervention | Gum chewing (with or without specific ingredients designed to promote salivation) | Gum chewing, mostly sugar-free gums sweetened with sorbitol / xylitol / aspartame; protocols ranged from single session to twice-daily chewing for up to 12 months (n=25 studies) |
| Comparison | No gum chewing | No gum chewing / usual care in most studies; several studies instead used comparators of artificial saliva or saliva substitute [30,31,33,34,40], sham chewing or oral exercise [17,26], or a lemon lozenge [34] (n=25 studies) |
| Outcomes | Rate of salivation / salivary flow rate (stimulated and unstimulated); self-reported xerostomia relief (e.g., Xerostomia Inventory); thirst. Meta-analysis primary outcome: unstimulated whole salivary flow rate (ml/min) | Stimulated and/or unstimulated salivary flow rate measured in 19-20 studies (9 positive, 10 no effect); self-reported xerostomia / dry mouth in 17 (12 positive, 5 no effect); thirst in 7 (6 positive, 1 no effect); mucosal moisture in 1. Meta-analysis of unstimulated salivary flow rate in 6 studies: SMD 0.44 (95% CI 0.22 to 0.66) (n=25 studies) |
| Study designs | Any setting (laboratory, clinical, nursing home, etc.); any study design; fully-refereed English-language studies only (abstracts and review papers excluded) | Haemodialysis units; cancer and palliative care; community and nursing-home / geriatric care; hospital preoperative setting (n=25 studies) |
| Timing | Any duration for the systematic review; meta-analysis restricted to daily gum chewing imposed for two or more weeks | Intervention periods from a single session/dose to 12 months; meta-analysis restricted to >=2 weeks of daily chewing (2 to 12 weeks) |
Search date: 31 March 2023. Databases: Medline; Scopus; Web of Science; Embase; Cochrane Library (CDSR and Central); Google Scholar; clinical trial registries (ClinicalTrials.gov, ISRCTN); reference-list (laddering); conferences; proprietary information
Questions and results
Gum chewing (sugar-free) vs No gum chewing (control)
Population: Elderly (>60 years) and medically compromised adults with xerostomia / dry mouth
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Self-reported thirst Various (preoperative period to 3 + 1 months) Gum chewing reduced self-reported thirst in most studies (6 of 7 positive, 1 no effect); not meta-analyzed. Source: Results 'Characteristics of included studies' paragraph; Table 2 · same question in other reviews | Narrative vote-count: of 7 studies measuring thirst, 6 found gum chewing reduced thirst [16,20,21,26,27,31] and 1 detected no effect [29]. | 7 studies | Ungraded |
Salivary flow rate, stimulated and/or unstimulated (narrative synthesis) Various (single session to 12 months) Across 19 studies the effect of gum chewing on stimulated and/or unstimulated salivary flow rate was mixed (9 positive, 10 no effect); this broad outcome was not meta-analyzed. Source: Results 'Characteristics of included studies' paragraph; Table 2 · same question in other reviews | Narrative vote-count: of 19 studies measuring stimulated and/or unstimulated saliva flow rate, 9 found a positive effect of gum chewing [17,18,22,24,27,35,36,38,39] and 10 detected no effect… | 19 studies | Ungraded |
Oral mucosal moisture 2-week chewing period (soft then hard gum, with 2-week wash-out) One small study found that chewing hard (but not soft) gum increased oral mucosal moisture. Source: Results 'Characteristics of included studies' paragraph; Table 2 (Nakagawa 2017 [22]) · same question in other reviews | Single study [22] (Nakagawa 2017): chewing hard gum significantly increased oral mucosal moisture whereas chewing soft gum did not. | 1 study · 12 participants | Ungraded |
Unstimulated whole salivary flow rate 2 to 12 weeks · Meta-regression by chewing duration Population: Elderly people and medically compromised people with xerostomia codex | SMD per week 0.06 | 6 studies · 291 participants | Ungraded |
Unstimulated whole salivary flow rate Gum chewed daily for >=2 weeks (2 to 12 weeks; multiple time points for Kim and Ozen) In elderly and medically compromised people with xerostomia, chewing sugar-free gum daily for two or more weeks produces a small but statistically significant increase in unstimulated whole salivary flow rate versus no gum (SMD 0.44, 95% CI 0.22 to 0.66); certainty of evidence was not formally graded. Source: Abstract; Results 'Effect of gum chewing on unstimulated rate of salivation'; Table 3; Fig. 5 (forest plot, random-effects diamond) · same question in other reviews | SMD 0.44 [0.22, 0.66] | 6 studies · 291 participants | Ungraded |
Self-reported xerostomia / symptoms of dry mouth Various (single session to 3 months) Gum chewing was linked with improved self-reported xerostomia / dry mouth in most studies (12 of 17 positive, 5 no effect); heterogeneous instruments precluded meta-analysis. Source: Results 'Characteristics of included studies' paragraph; 'Systematic review' discussion; Table 2 · same question in other reviews | Narrative vote-count: of 17 studies measuring self-reported xerostomia / dry mouth, 12 found a positive effect of gum chewing [18,19,21,23,24,25,26,27,30,31,38,40] and 5 detected no effect [17,29,33,34,37]. No study… | 17 studies | Ungraded |
AMSTAR 2 appraisal
Two independent extractors rated each item. Their ratings are shown side by side because they have not been reconciled yet. The overall rating follows Shea et al. 2017: one critical flaw gives Low, more than one gives Critically Low.
| Item | Extractor A | Extractor B | Agree |
|---|---|---|---|
| 1Research question includes PICO components | Yes | Yes | yes |
| 2Protocol established before the reviewcritical | Partial Yes | Yes | no |
| 3Choice of study designs explained | No | Yes | no |
| 4Comprehensive literature searchcritical | Partial Yes | Yes | no |
| 5Study selection in duplicate | Yes | Yes | yes |
| 6Data extraction in duplicate | Yes | Yes | yes |
| 7List of excluded studies with reasonscritical | No | No | yes |
| 8Included studies described in detail | Partial Yes | Yes | no |
| 9Risk of bias assessed satisfactorilycritical | RCT: Yes · NRSI: Yes | NRSI: Yes · RCT: Yes | no |
| 10Funding of included studies reported | No | No | yes |
| 11Appropriate meta-analysis methodscritical | RCT: Yes · NRSI: N/A | NRSI: N/A · RCT: Yes | no |
| 12Impact of risk of bias on the pooled results | No | No | yes |
| 13Risk of bias accounted for in interpretationcritical | Yes | Yes | yes |
| 14Heterogeneity explained | Yes | Yes | yes |
| 15Publication bias investigatedcritical | Yes | Yes | yes |
| 16Conflicts of interest reported | Yes | Yes | yes |
| Overall | Low | Low | yes |
Included primary studies 26
Open as a trial list| Study | Also included by | Outcomes it informs here | Trial PICO | Results |
|---|---|---|---|---|
| Al-Haboubi 2012 The potential benefits of sugar‐free chewing gum on the oral health and quality of life of older people living in the community: a… DOI:10.1111/j.1600-0528.2012.00685.x | 1 other review | not stated | not extracted yet | not extracted yet |
| Simons 1997 The Effect of Chlorhexidine/Xylitol Chewing-Gum on Cariogenic Salivary Microflora: A Clinical Trial in Elderly Patients DOI:10.1159/000262382 | 1 other review | not stated | not extracted yet | not extracted yet |
| Aagaard 1992 Comparison between new saliva stimulants in patients with dry mouth: a placebo‐controlled double‐blind crossover study DOI:10.1111/j.1600-0714.1992.tb01369.x | this review only | not stated | not extracted yet | not extracted yet |
| Abelson 1990 Biotransformation of 4-androstene-3,17-dione by green cell suspension of Marchantia polymorpha: stereoselective reduction at carbon 17. PMID:1990235 | this review only | not stated | not extracted yet | not extracted yet |
| Allida 2021 A RandomisEd ControLled TrIal of ChEwing Gum to RelieVE Thirst in Chronic Heart Failure (RELIEVE-CHF) DOI:10.1016/j.hlc.2020.09.004 | this review only | not stated | not extracted yet | not extracted yet |
| Bjornstrom 1990 matched by author and year (probable) | this review only | not stated | not extracted yet | not extracted yet |
| Björnström et al 1990 matched by author and year (probable) | this review only | not stated | not extracted yet | not extracted yet |
| Bots 2005a The management of xerostomia in patients on haemodialysis: comparison of artificial saliva and chewing gum DOI:10.1191/0269216305pm1009oa | this review only | not stated | not extracted yet | not extracted yet |
| Bots 2005b Chewing gum and a saliva substitute alleviate thirst and xerostomia in patients on haemodialysis DOI:10.1093/ndt/gfh675 | this review only | Unstimulated whole salivary flow rate | not extracted yet | not extracted yet |
| Davies 2000 A comparison of artificial saliva and chewing gum in the management of xerostomia in patients with advanced cancer DOI:10.1191/026921600672294077 | this review only | not stated | not extracted yet | not extracted yet |
| Dehghanmehr 2018 matched by author and year (probable) | this review only | not stated | not extracted yet | not extracted yet |
| Duruk & Eser 2016 The Null Effect of Chewing Gum During Hemodialysis on Dry Mouth DOI:10.1097/nur.0000000000000234 | this review only | not stated | not extracted yet | not extracted yet |
| Fan 2013 Study on the Clinical Significance and Related Factors of Thirst and Xerostomia in Maintenance Hemodialysis Patients DOI:10.1159/000355717 | this review only | Unstimulated whole salivary flow rate | not extracted yet | not extracted yet |
| Garcia 2019 Menthol chewing gum on preoperative thirst management: randomized clinical trial. PMID:31596415 | this review only | not stated | not extracted yet | not extracted yet |
| Gueimonde 2016 Supplementation of xylitol-containing chewing gum with probiotics: a double blind, randomised pilot study focusing on saliva flow and… DOI:10.1039/c5fo01497b | this review only | not stated | not extracted yet | not extracted yet |
| Jagodzinska 2011 Three Months of Regular Gum Chewing Neither Alleviates Xerostomia nor Reduces Overhydration in Chronic Hemodialysis Patients DOI:10.1053/j.jrn.2010.08.002 | this review only | not stated | not extracted yet | not extracted yet |
| Kaae 2016 Xerostomia after Radiotherapy for Oral and Oropharyngeal Cancer: Increasing Salivary Flow with Tasteless Sugar-free Chewing Gum. PMID:27200297 | this review only | not stated | not extracted yet | not extracted yet |
| Kaae 2020 A randomized phase III trial for alleviating radiation-induced xerostomia with chewing gum DOI:10.1016/j.radonc.2019.09.013 | this review only | not stated | not extracted yet | not extracted yet |
| Kim 2021 Simple oral exercise with chewing gum for improving oral function in older adults DOI:10.1007/s40520-020-01606-z | this review only | Unstimulated whole salivary flow rate | not extracted yet | not extracted yet |
| Nakagawa 2017 Effects of gum chewing exercises on saliva secretion and occlusal force in community‐dwelling elderly individuals: A pilot study DOI:10.1111/ggi.12670 | this review only | not stated | not extracted yet | not extracted yet |
| Olsson 1991 The effect of a chewing gum on salivary secretion, oral mucosal friction, and the feeling of dry mouth in xerostomic patients DOI:10.3109/00016359109005919 | this review only | not stated | not extracted yet | not extracted yet |
| Ozen 2021 The effect of chewing gum on dry mouth, interdialytic weight gain, and intradialytic symptoms: A prospective, randomized controlled trial DOI:10.1111/hdi.12878 | this review only | Unstimulated whole salivary flow rate | not extracted yet | not extracted yet |
| Risheim & Arneberg 1993 Salivary stimulation by chewing gum and lozenges in rheumatic patients with xerostomia DOI:10.1111/j.1600-0722.1993.tb01644.x | this review only | Unstimulated whole salivary flow rate | not extracted yet | not extracted yet |
| Said & Mohammed 2013 matched by author and year (probable) | this review only | not stated | not extracted yet | not extracted yet |
| Simons 2002 The Effect of Medicated Chewing Gums on Oral Health in Frail Older People: A 1‐Year Clinical Trial DOI:10.1046/j.1532-5415.2002.50355.x | this review only | not stated | not extracted yet | not extracted yet |
| Stewart 1998 Comparison between saliva stimulants and a saliva substitute in patients with xerostomia and hyposalivation DOI:10.1111/j.1754-4505.1998.tb01136.x | this review only | Unstimulated whole salivary flow rate | not extracted yet | not extracted yet |
Overlap with other reviews
Reviews that include the same primary studies are not independent evidence. Shared counts match studies by PMID, DOI or NCT, and otherwise by author and year (a probable match).