Poor oral health predicts cognitive impairment in elders

Abstract Background Tooth loss, periodontal disease, dementia, and Alzheimer’s disease share several risk factors in older adults. Several previous studies have reported positive associations between these dental problems and global cognitive defects. However, limited is known about the relationships among multiple dental/periodontal statuses and different cognitive domains. Method This six‐year (2011‐2017) cohort study includes 515 older adults (65+). Global cognition was assessed by Montreal cognitive assessment‐Taiwan version (MoCA‐T). For cognitive domains, we used logical memory tests (immediate and delayed theme and free recall) in Wechsler Memory Scale‐Third Edition (WMS‐III) to assess memory. Trail Making Test A and B was used to assess attention and executive function, respectively. Digit span‐forward and backward was used to evaluate attention and working memory/short‐term memory, respectively. Verbal fluency tests were used to assess category/semantic fluency. A Z‐score was calculated for each cognitive domain‐specific test according to baseline mean and standard deviation. Oral health status includes tooth defect (dental caries, tooth wear, cervical abrasion, retained root or crown fracture), periodontal health (disease severity from healthy periodontal status, gingivitis to periodontitis), and arch integrity (no tooth loss nor retained root or crown fracture). Generalized linear mixed models were used to assess the associations above adjust important covariates. Result At baseline, periodontitis was associated with poor performance in executive function [Trail Making Test A: b = ‐0.14, 95% confidence interval (CI) = ‐0.27 to ‐0.01]. The association between baseline severity of tooth defect and poor memory decreased (logical memory‐immediate theme recall: b = ‐0.05, 95% CI = ‐0.10 to ‐0.01); similarly finding was found for attention domain (digit span‐forward: b = ‐0.04, 95% CI = ‐0.07 to ‐0.001). At baseline, loss of arch integrity was associated with a better working memory/short‐term memory (digit span‐backward: β = 0.18, 95% CI = 0.01 to 0.36); as follow‐up time increased, this association decreased over six years (β = ‐0.04, 95% CI = ‐0.07 to ‐0.003). Conclusion Periodontitis, tooth defects, or arch integrity was associated with poor performance of cognitive domains (memory, attention, and executive function) over time. A oral health evaluation may serve as predictors of the preclinical phase of dementia in its upcoming years.