AbstractBackgroundRecent studies link tooth loss with dementia, however, the mechanism that underlies this association is not known. One hypothesis attributes this association to loss of sensory stimulation from the masticatory apparatus. Since establishment of occlusal contacts between the opposing teeth enables functionality (e.g., mastication, etc.) as well as supports the facial structure by maintaining static occlusal contacts, hence, this study examines the effect of loss of occlusal support (number of occlusal pairs) on dementia risk.MethodThis study included 4013 dementia‐free participants (1880 males, 2133 females), aged 30‐93 years (mean 47.23 years) from Finnish Health 2000 survey. Tooth count and number of occlusal pairs (maximum 10 pairs) were recorded in oral clinical examination. Dementia diagnosis up till 2015 was retrieved from hospital discharge and causes of death registers. Cox regression models were generated to assess 15‐year dementia risk against loss of occlusal pairs. Association was adjusted for age, gender, years of education, cardiovascular risk, socioeconomic status, dietary index, depression, and overall tooth count. Analysis was further expanded by stratifying number of occlusal pairs into having ≥8 pairs, 4‐7 pairs, and ≤3 pairs. Sensitivity analysis was conducted for participants aged ≥55 years.Result137 participants developed dementia over 15 years. Fully adjusted model indicated 13% higher risk of dementia for each occlusal pair lost (Model 3). Further adjustment for overall tooth count increased dementia risk to 21% (Model 4). In stratified analysis, having ≤7 occlusal pairs carried significantly higher risk of dementia. This association appeared to be dose‐dependent, with having 4‐7 pairs carrying twice the dementia risk while having ≤3 pairs carrying almost three times the dementia risk in comparison to having ≥8 pairs. The findings were corroborated by sensitivity analysis for each occlusal pair lost. In stratified sensitivity analysis having ≤3 pairs was associated with higher risk of dementia but hazards ratio for having 4‐7 pairs failed to achieve statistical significance.ConclusionPreliminary results indicate that loss of occlusal support/number of occlusal pairs independently increases dementia risk. Further in‐depth studies assessing the impact of particular tooth types lost and the possible mechanisms are warranted.