While the oral health of persons with dementia has been shown to be poor, no systematic reviews have been published that examined the topic in depth, including participants with dementia representing the full spectrum of disease severity, and evaluating a broad scope of oral health assessments. The aim of this study was to conduct a current literature review to fill this gap in knowledge. A systematic search of 5 databases (CINAHL, PubMed, EMBASE, Scopus, and ISI Web of Science) was conducted to identify all relevant studies published up to May 2016. There were no exclusions related to study type, severity of dementia, dentate status, or living arrangements. Results were reported descriptively and summarized. Meta-analyses were performed where possible and reported as mean difference (MD) or standardized mean difference (SMD), with a 95% confidence interval (CI). Twenty-eight studies were identified. Assessments were conducted of tooth status, active dental caries, hygiene (plaque/calculus) of natural and artificial teeth, periodontal diseases, denture status (retention, stability, denture-related mucosal lesions), and oral health-related quality of life. Across all evaluations, persons with dementia generally had scores/results suggestive of poor oral health. In metaanalyses, compared with persons without dementia, those with dementia had a significantly fewer number of teeth (MD, −1.52; 95% CI, −0.2.52 to −0.52; P = 0.003; n = 13 studies), more carious teeth (SMD, 0.29; 95% CI, 0.03 to 0.48; P = 0.028; n = 9), significantly worse oral hygiene evaluated using a broad range of assessment tools (SMD,