Toothbrushing Ability in Older Adults Across Stages of Cognitive Impairment

Background/Objectives: Cognitive impairment can compromise toothbrushing and other oral self-care functions, increasing the risk of oral diseases and related complications. However, how toothbrushing ability declines across stages of cognitive impairment remains unclear. This study aimed to describe functional deficits in toothbrushing among older adults with different levels of cognitive function. Method: Sixty-five older adults (14 cognitively healthy and 51 with documented cognitive impairment) were classified into five cognitive levels based on Standardized Mini-Mental State Examination scores. Participants completed a toothbrushing task as they normally would at home. Performance was videotaped, coded, and evaluated across four domains (task initiation, completion, thoroughness, and quality) with total scores reflecting overall toothbrushing ability. Overall performance, functional deficits, and assistance needs were analyzed in relation to cognitive levels. Results: Participants averaged 76.5 years of age. Toothbrushing ability declined gradually with worsening cognitive impairment, followed by a sharp deterioration at the profound stage (e.g., SMMSE ≤ 5). Compared with cognitively healthy participants (n = 14), those with mild cognitive impairment (MCI, n = 20) or mild (n = 10), moderate (n = 10), or severe dementia (n = 11) lost an average of 3%, 8%, 12%, and 37% of overall toothbrushing ability, respectively. Brushing efficiency declined earlier and more rapidly, decreasing by 13% in MCI and up to 46% in severe dementia (p < 0.001). All participants with MCI or mild dementia completed the task independently, whereas 20% with moderate dementia and 80% with severe dementia required assistance to initiate or complete the task. Conclusions: Overall toothbrushing ability remains relatively preserved until the later stages of cognitive impairment, but brushing quality deteriorates much earlier and quicker. These findings highlight the importance of early caregiver-patient partnerships, functionally tailored oral self-care rehabilitation, and personalized caregiver training to support oral hygiene among older adults with cognitive impairment.