Prevalence of orofacial pain in individuals with mild cognitive impairment or dementia: A systematic review and meta-analysis.

BACKGROUND: This systematic review investigated the prevalence of orofacial pain in patients with mild cognitive impairment (MCI) or dementia.

MATERIALS AND METHODS: The search was conducted in five databases (Medline (Ovid), Embase (Ovid), CINAHL, Scopus and LILACS), in three grey literature sources and in included articles' reference lists. Three independent reviewers performed study selection, quality appraisal and data extraction. The risk of bias was assessed with the National Institutes of Health tool. Prevalence was calculated using the random-effects model. Subgroup analysis and meta-regression were used to explore the heterogeneity of results.

RESULTS: The database and grey literature search led to 12 246 results, from which nine studies were included; a further four were selected through citation searching. The total sample comprised 6115 patients with dementia and 84 with MCI. All studies had high risk of bias. The overall estimated pooled prevalence of orofacial pain among dementia participants was 19.0% (95% CI, 11.0%-27.0%; I2 , 97.1%, P < .001). Only one study included MCI participants, among which the prevalence of orofacial pain was 20.5%. Subgroup analysis demonstrated that the different sources of diagnosis might explain the heterogeneity. A higher prevalence of orofacial pain was observed in dementia participants aged over 80 years or living in nursing homes. Meta-regression analysis showed a nonlinear relationship between age and the prevalence of orofacial pain.

CONCLUSIONS: The pooled data from the primary studies revealed that 2 out of 10 patients with dementia have orofacial pain. Further research is needed to clarify the magnitude in individuals with MCI.