Number of natural teeth, denture use and mortality in Chinese elderly: a population-based prospective cohort study

Abstract

Background: The associations between the number of natural teeth/denture use and all-cause mortality remain unclear due to lake of investigation for the potential interaction between tooth loss and denture use and for the potential changes in these exposures over time in older adults. We undertake this study to evaluate the associations of the number of natural teeth and/or denture use with mortality in Chinese elderly. Methods: This is a prospective cohort study of 36,283 older adults (median age: 90). The number of natural teeth and denture use were collected with structured questionnaire. We evaluated hazard ratios (HRs) and confidence intervals (CIs) using a Cox proportional hazards model adjusting for demographic factors, education, income, lifestyle factors, and comorbidities. Results: We documented 25,857 deaths during 145,947 person-years of observation. Compared to those with 20+ teeth, tooth loss was associated with a gradual increase in mortality, with an adjusted HR of 1.14 (95% CI, 1.06 to 1.23) for those with 10-19 teeth, 1.23 (95% CI, 1.15 to 1.31) for those with 1-9 teeth, and 1.35 (95% CI, 1.26 to 1.44) for those without natural teeth. Denture use was associated with lower risk of mortality (adjusted HR 0.81; 95% CI, 0.77 to 0.84). Subgroup analyses indicated that the benefit of denture use was greater in men than in women (P = 0.02) and tended to decrease with age (P < 0.001). The effects of denture use did not differ among various degrees of tooth loss (P = 0.17). Conclusions: Tooth loss was associated with an increased risk of mortality in older adults. Denture use provided a protective effect against death for all degrees of tooth loss however, this effect appeared to be modified by sex and age.

Association between denture use, chewing ability, and all-cause mortality in middle-aged and older adults who exercised regularly in Korea

“…Furthermore, it was reported that individuals with inadequate masticatory ability, including denture wearers, had a 15% or higher risk of mortality than those with good chewing function 16 , which was similar to that observed in this study. However, in a prospective cohort study, including elderly individuals in China 14 , Yuan et al reported a decrease in mortality (aHR = 0.81; 95% CI: 0.77–0.84) with denture use. The difference may be attributed to the higher number of missing teeth in denture wearers than in non-denture wearers in their study.…”

“…As previously reported, individuals with fewer teeth or poor masticatory ability, due to non-replacement of teeth, are at a higher risk of developing cognitive impairment, such as dementia, than those with more than 20 teeth and good masticatory ability 17 , 18 . Numerous studies have reported that masticatory discomfort, caused by tooth loss, is a risk factor for increased mortality 11 , 13 , 14 , 16 . Masticatory discomfort directly influences individual, physical, psychological, and oral health 19 .…”

Association between presence of 20 or more natural teeth and all-cause, cancer-related, and cardiovascular disease-related mortality: Yamagata (Takahata) prospective observational study

“…The mechanism underlying the association between the presence of < 20 natural teeth and the risk for all-cause mortality is unclear; however, some hypotheses have been suggested. Events such as tooth loss, lead to hypoactivity of the masticatory system and ultimately, insufficient nutrient intake, which can have a negative influence on general health [ 13 , 31 ]. Yoshihara et al reported that participants with < 20 teeth had a significantly lower total protein, animal protein, sodium, vitamin D, vitamin B1, vitamin B6, niacin, and pantothenic acid intake than participants with ≥ 20 teeth [ 32 ].…”

“…In the multivariate-adjusted model, HR was adjusted for age, sex, smoking habit, alcohol consumption, educational status, hypertension, DM, and perceived mental stress. These adjusted factors for the Cox regression model have also been used in previous studies that surveyed the association between number of teeth and mortality [ 13 – 15 , 19 , 21 ].…”

“…1), many prospective cohort studies worldwide have attempted to survey this relationship. Among these, several have surveyed the relationship between the presence of ≥ 20 natural teeth and mortality [13][14][15][16]. To the best of our knowledge, seven prospective studies on this topic have been published in Japan [17][18][19][20][21][22][23].…”