It has been suggested that tooth loss in later life might increase dementia incidence. The objective of this analysis is to systematically review the current evidence on the relationship between the number of remaining teeth and dementia occurrence in later life. A search of multiple databases of scientific literature was conducted with relevant parameters for articles published up to March 25th, 2017. Multiple cohort studies that reported the incidence of dementia and residual teeth in later life were found with observation periods ranging from 2.4 to 32 years. Random-effects pooled odds ratios (OR) and 95% confidence intervals (CI) were estimated to examine whether high residual tooth number in later life was associated with a decreased risk of dementia. Heterogeneity was measured by I2. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to assess the overall quality of evidence. The literature search initially yielded 419 articles and 11 studies (aged 52 to 75 at study enrollment, n = 28,894) were finally included for analysis. Compared to the low residual teeth number group, the high residual teeth number group was associated with a decreased risk of dementia by approximately 50% (pooled OR = 0.483; 95% CI 0.315 to 0.740; p < 0.001; I2 = 92.421%). The overall quality of evidence, however, was rated as very low. Despite limited scientific strength, the current meta-analysis reported that a higher number of residual teeth was associated with having a lower risk of dementia occurrence in later life.

Objectives: The purpose of this study is to investigate the effect of the comprehensive oral care program on oral health status and symptoms in head and neck cancer (HNC) patients undergoing radiotherapy. Methods: This was a quasi-experimental study using a non-equivalent control group in non-synchronized design. All participants including control and experimental group were asked for the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire H&N35 (EORTC QLQ-H&N35) and given an oral health education 4 times at baseline, immediate postradiotherapy, 3 months after radiotherapy, and 6 months after radiotherapy. In each visit except for final, the experimental group was given fluoride varnish application and fluoride mouth rinsing solution for daily use. Oral health examination for dental caries, plaque score (PS), bleeding on probing (BOP), and salivary flow rate was performed in baseline and 6 months after radiotherapy. Statistical analyses were done by paired t-tests and mixed ANCOVA repeated-measures analysis. Results: From November 1, 2013 to October 31, 2015, a total 61 patients undergoing radiotherapy for HNC cancer were enrolled (30 in control and 31 in experimental groups). Decrease in salivary flow rate was comparable between 2 groups. Dental caries increased in control group (P = .006); PS and BOP were decreased in experimental group (P < .001 and .004, respectively). Experimental group showed lower swallowing, speech problems, and less sexuality scores in EORTC QLQ-H&N35 than control group. Conclusion: We found improvement in oral health and the quality of life in HNC patients with comprehensive oral care intervention by dental professionals. Communicating and cooperating between the healthcare and dental professionals is needed to raise the quality of health care services for HNC patients receiving radiotherapy.

Han DH, et al. J Korean Med Sci. 2012 Sep;27(9):1098-1104. http://dx.doi.org/10.3346/jkms.2012.27.9.1098