The association between oral hygiene and metabolic dysfunction-associated steatotic liver disease - a systematic review

Clinical Snapshot

Key Findings

• P Value: Not reported at the review level; individual study p-values not extractable from the abstract

• Effect Size: Not quantified; narrative synthesis only. Five of six studies reported an inverse association between higher tooth brushing frequency and NAFLD/NASH outcomes. One study reported significantly worse liver parameters in NASH patients without regular dental visits (>1 visit/year) compared to those with regular attendance.

• Primary Outcome: Association between oral hygiene frequency (tooth brushing, dental visits) and incidence, prevalence, or progression of NAFLD/NASH/MASLD

• Nnt Or Sensitivity: Not calculable from available data; no pooled risk estimates provided. The review does not report odds ratios, relative risks, or hazard ratios at the synthesis level.

• Confidence Interval: Not reported; no meta-analysis performed

Clinical Application

Tooth brushing frequency and dental attendance are low-cost, low-risk behavioural interventions with established benefits for oral health independent of any hepatic effect. Recommending twice-daily brushing and regular dental review is feasible in any clinical setting and carries no harm. However, clinicians should frame this as adjunctive lifestyle advice rather than a targeted MASLD intervention until higher-quality evidence is available. MASLD affects an estimated 25–30% of Australian adults and is a leading cause of chronic liver disease in Australia. The RACGP guidelines for preventive care and the National Preventive Health Strategy both support integrated approaches to metabolic health. Dental care access in Australia is variable — public dental services are limited, and out-of-pocket costs are significant for many patients, particularly those in rural and remote areas. PBS-listed pharmacotherapies for MASLD remain limited (resmetirom is not yet TGA-approved in Australia as of mid-2026), making lifestyle interventions — including oral hygiene — potentially more prominent in the management conversation. Clinicians should note that the Australian Dental Association already recommends twice-daily brushing; this review provides preliminary biological rationale for reinforcing this advice in metabolically at-risk patients. Integration of dental health screening into chronic disease management plans (CDMPs) under MBS item numbers may be worth considering as evidence matures. Adults with established MASLD/NAFLD/NASH or those at elevated metabolic risk (obesity, type 2 diabetes, metabolic syndrome). The findings are most relevant to patients already engaged in hepatology or gastroenterology care, and to primary care clinicians managing cardiometabolic risk.

Abstract

BACKGROUND: Given the increasingly evident links between oral health and systemic health, the aim of this review was to investigate whether oral hygiene practices influence the risk or progression of metabolic dysfunction-associated steatotic liver disease (MASLD). The findings support the potential importance of good oral hygiene and regular dental visits, especially for patients with MASLD. METHODS: This systematic review was registered with PROSPERO (CRD420251041530), and PubMed, Scopus, Embase and Web of Science were used for literature research up to June 2026. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, screening, study selection and quality check were performed using Rayyan and the Joanna Briggs Institute (JBI) critical appraisal checklists. Studies assessing the potential link between the frequency of oral hygiene procedures and the incidence, prevalence or progression of MASLD were selected for a systematic synthesis. The old terms non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) were considered as well. RESULTS: A total of 570 results were identified of which six studies met the inclusion criteria. Five of them reported a correlation between higher tooth brushing frequency and a lower incidence, prevalence or progression of NAFLD/NASH compared to individuals with lower tooth brushing frequency. Notably, one study revealed significantly worse liver parameters among NASH patients without regular dental visits than among those who visited a dentist more than once a year. CONCLUSIONS: An association between oral hygiene habits and NAFLD/NASH was found in all included studies. A greater frequency of daily tooth brushing as well as regular dental visits might have beneficial effects on both the development and progression of fatty liver disease. However, there is not enough evidence to establish causality yet and the impact of confounding factors must be further investigated. CLINICAL TRIAL REGISTRATION: Not applicable.

References

1. 1.Gerold, A., Walter, F.-S., Waller, J., & Ferger, B. (2026). The association between oral hygiene and metabolic dysfunction-associated steatotic liver disease - a systematic review. BMC Oral Health. https://doi.org/10.1007/s13679-024-00574-z