Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article


Master of Science


Epidemiology and Biostatistics


Gomaa, Noha

2nd Supervisor

Stranges, Saverio


3rd Supervisor

Nicholson, Kathryn



The connection between oral health and other non-communicable chronic conditions—commonly referred in the dental literature as the oral-systemic health connection—emphasizes the role of oral health care on both oral diseases and chronic conditions, particularly in vulnerable populations like the elderly. This thesis comprises 2 studies: the first is a systematic review on the impact of oral health care interventions, as an indicator of access to oral health care, on chronic conditions of which their co-existence would result in multimorbidity; the second study is a cross-sectional investigation of the associations between oral health, access to oral health care, and multimorbidity among middle-aged and older Canadians. This quantitative analysis revealed a significant inverse relationship between the number of dental visits within the last year and both oral health and multimorbidity. Poor oral health was also significantly associated with multimorbidity, with a stronger association observed among females. The availability of dental insurance, frequency of dental visits, and affordability of dental care were shown to modify the association between oral health indicators and multimorbidity. Future research should prioritize the development of interventions and policies to provide access to dental care for Canadians, especially in the aging population.

Summary for Lay Audience

Oral diseases impact nearly 3.5 billion people worldwide. Research has highlighted the connection between oral health and other major chronic conditions, such as heart diseases, diabetes and multimorbidity, which is the co-existence of two or more chronic conditions, demonstrating that oral diseases while important in and of themselves, may have implications beyond the mouth. This relationship is attributed to several pathways, including the spread of inflammation and oral bacteria to different body systems. Shared risk factors such as unhealthy lifestyle including smoking, alcohol consumption, and poor nutrition, can contribute to both oral diseases and multimorbidity, creating a harmful cycle. Moreover, the psychosocial impact of oral diseases can contribute to stress and reduced quality of life, potentially affecting the development of chronic conditions, particularly among vulnerable populations like the elderly. These interconnections further highlight the potential role of oral health care in mitigating chronic conditions. In Canada, dental care is excluded from primary care, further contributing to the division between oral health and overall health. There is therefore currently a special interest in investigating how access to oral health care can influence the association between oral health and multimorbidity, particularly in adults who experience the interconnectedness of aging, chronic conditions, oral diseases, and limited dental care access.

This thesis aimed to fill a knowledge gap regarding the potential contribution of oral health care on chronic conditions, multimorbidity and their relationship with oral health. Through a systematic review, we aimed to synthesize evidence on the impact of access to clinical oral health interventions and chronic conditions. Although specific studies on multimorbidity were limited, we concluded that clinical oral health interventions can mitigate the risk of several chronic conditions. Next, upon analyzing data from the Canadian Longitudinal Study of Aging, we found a significant association between dental care utilization, including recent visits to the dentist, and improved oral health, as well as a reduced risk of multimorbidity.

Future research should focus on integrated health care approaches that address shared risk factors, promote healthy behaviours and improvement of access to oral health care.

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.