Association of tooth location, occlusal support and chewing ability with cognitive decline and incident dementia

Emerging evidence suggests association of tooth loss with impaired cognition. However, the differential effects of anterior versus posterior tooth loss, occlusal support loss and chewing ability are not considered comprehensively.

We conducted cross-sectional (N = 4036) and longitudinal analyses (N = 2787) on data from Health 2000 and 2011 Surveys for associations of posterior occlusal support loss, anterior versus posterior tooth loss, and chewing ability with baseline cognition and 11-year cognitive decline. Additionally, 15-year incident dementia risk was investigated (N = 4073).

After considering relevant confounders and potential reverse causality bias, posterior occlusal support loss significantly increased dementia risk across all categories indicative of posterior occlusal support loss (hazard ratios [HRs] between 1.99 and 2.89). Bilateral inadequate posterior occlusal support was associated with 11-year decline in overall cognition (odds ratio [OR] = 1.48:1.00-2.19), and unilateral inadequate posterior occlusal support with total immediate (OR = 1.62:1.14-2.30) and delayed recall decline (OR = 1.45:1.03-2.05). Moreover, posterior tooth loss was associated with dementia (HR = 2.23:1.27-3.91) and chewing ability with total immediate decline (OR = 1.80:1.04-3.13).

Posterior tooth and occlusal support loss significantly increases dementia risk. The impact of posterior occlusal support loss appears to be dose-dependent, and this effect is distinct from that of dentures. Dental healthcare services should be particularly attentive to the state of posterior dentition. Further studies exploring possible mechanisms are warranted.