Masticatory function indicators and frailty risk in older adults: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Declines in oral functions, particularly mastication, contribute to frailty in older adults. Existing studies have applied diverse indicators to evaluate masticatory function, including both subjective reports and objective measurements. However, their associations with frailty and prefrailty remain inconsistent.

PURPOSE: The purpose of this systematic review and meta-analysis was to synthesize evidence on these clinical masticatory indicators and their connection to frailty.

MATERIAL AND

METHODS

Seven databases (PubMed, Embase, Scopus, Web of Science, CNKI, Wanfang, Sinomed) were searched to June 2025. Eligible were observational studies of adults ≥60 years evaluating masticatory function and frailty with validated tools. Study quality was appraised using the Agency for Healthcare Research and Quality (AHRQ) checklist and Newcastle-Ottawa Scale (NOS). Odds ratios (ORs) and standardized mean differences (SMDs) were pooled with random-effects models (α=.05).

RESULTS

Nineteen studies (16 cross-sectional, 3 cohort) including 20 917 participants (mean ±standard deviation age 73.8 ±1.7 years; 56% women) were analyzed. Fourteen studies used the frail/prefrail/robust classification, 5 compared frail versus nonfrail. Self-reported masticatory difficulty was associated with prefrailty (OR=1.66, 95% CI[1.25,2.20], P<.001) and frailty (OR=2.28, 95% CI[1.70,3.05], P<.001). Maximum occlusal force <500 N was linked with prefrailty (OR=1.66, 95% CI[1.20,2.30], P=.002) and frailty (OR=2.56, 95% CI[1.74,3.78], P<.001). As a continuous variable, occlusal force was reduced only in frailty (SMD=-0.70, 95% CI[-0.83,-0.56], P<.001). Masticatory performance <155 mg/dL was associated with increased prefrailty/frailty risk (OR=1.55, 95% CI[1.05,2.28], P=.03). Tongue pressure (SMD=-0.26, 95% CI[-0.49,-0.03], P=.030) and mixing ability (SMD=-0.29, 95% CI[-0.48,-0.10], P=.003) were lower in prefrail versus robust groups, with progressive declines.

CONCLUSIONS

Multiple masticatory indicators have been associated with frailty and prefrailty. Threshold-type measures (self-reported masticatory difficulty, occlusal force <500 N, masticatory performance <155 mg/dL) show diagnostic value, while continuous measures (tongue pressure, mixing ability) decline early in prefrailty. These findings support incorporating masticatory assessment into frailty screening and highlight oral-muscle interventions for early frailty management.