Findings

What do systematic reviews say?

6 questions · 6 findings · 3 reviews · Dental caries

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No studies found 0 · 0%GRADE not reported 5 · 83.3%Very low 0 · 0%Low 0 · 0%Moderate 1 · 16.7%High 0 · 0%

Daily chewing gum for 2 weeks or longer vs No gum chewing or control

Salivary flow rate (unstimulated) · Elderly (>60 years) and medically compromised adults with xerostomia / dry mouth

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1 finding from 1 review

The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes
2 to 12 weeks · Meta-regression slope for change in standardized salivary flow rate per additional week of chewing · Meta-regression by chewing duration
SMD per week 0.06
6 studies · 291 participants
GRADE not reported

Gum chewing (sugar-free) vs No chewing gum

Salivary flow rate (unstimulated) · Elderly (>60 years) and medically compromised adults with xerostomia / dry mouth

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.

1 finding from 1 review

The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes
Gum chewed daily for >=2 weeks (2 to 12 weeks; multiple time points for Kim and Ozen) · Haemodialysis units, elderly / geriatric care, cancer and palliative care, and xerostomia / hyposalivation clinics (studies from multiple countries)
SMD 0.44 [0.22, 0.66]
6 studies · 291 participants
GRADE not reported

Gum chewing (sugar-free) vs No chewing gum

Salivary flow rate · Elderly (>60 years) and medically compromised adults with xerostomia / dry mouth

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.

1 finding from 1 review

The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes
Various (single session to 12 months) · Haemodialysis units, elderly / geriatric care, cancer and palliative care, and xerostomia / hyposalivation clinics (studies from multiple countries)
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
GRADE not reported

Anorexia nervosa (as exposure; diagnosed by DSM-III/III-R/IV/V) vs Healthy controls

Salivary flow rate (stimulated) · Patients with anorexia nervosa aged >=12 years (mean age ~18.4; entirely female in reported data), general community-dwelling population

Stimulated salivary flow rate was significantly lower in anorexia nervosa patients than controls, but only unstimulated flow was meta-analyzed; this outcome is ungraded.

1 finding from 1 review

The influence of anorexia nervosa on oral health and related parameters potentially relevant to orthodontic treatment:… 2025 All outcomes
Clinical dental/oral examination; case-control studies and controlled clinical trials in Europe (mainly Poland, Italy, France, Germany), Australia and the USA
Stimulated salivary flow rate significantly lower in anorexic patients (Paszynska 2015 Nov 1.20 vs 1.57 ml/min, p=0.005; Paszynska 2018 0.99 vs 1.45 ml/min, p<0.00001); reported narratively, not meta-analyzed
2 studies · 126 participants
GRADE not reported

Anorexia nervosa (as exposure; diagnosed by DSM-III/III-R/IV/V) vs Healthy controls

Salivary flow rate (unstimulated) · Patients with anorexia nervosa aged >=12 years (mean age ~18.4; entirely female in reported data), general community-dwelling population

Anorexia nervosa probably reduces unstimulated salivary flow rate versus healthy controls (MD -0.27 ml/min, 95% CI -0.31 to -0.24; moderate certainty).

1 finding from 1 review

The influence of anorexia nervosa on oral health and related parameters potentially relevant to orthodontic treatment:… 2025 All outcomes
Clinical dental/oral examination; case-control studies and controlled clinical trials in Europe (mainly Poland, Italy, France, Germany), Australia and the USA
MD -0.27 [-0.31, -0.24]
4 studies · 316 participants
Moderate

Gastroesophageal or laryngopharyngeal reflux (GERD/LPR) vs Healthy controls

Salivary function impairment (buffering capacity, flow rate, oral pH) · Adults with gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux (LPR)

Reflux is associated with impaired salivary function (notably reduced buffering capacity) as a proposed pathophysiological mechanism, based on several ungraded studies.

1 finding from 1 review

Laryngopharyngeal reflux, gastroesophageal reflux and dental disorders: A systematic review. 2020 All outcomes
Adult patients in gastroenterology, ENT and dental clinical settings
Mixed/controversial salivary findings: reduced salivary buffering capacity supported in three studies (Correa, Holbrook, Filipi) with low oral pH and reduced flow as additional factors in GERD patients, but Meurman and Schroeder found no significant salivary abnormalities; no pooled estimate.
6 studies
GRADE not reported