Oral health is a fundamental part of the general health and well-being of an individual. It can be achieved by maintaining good oral hygiene. It is not only about having clean teeth and fresh breath but is also one of the best ways to help maintain good overall health. Poor oral health has been reported as a risk factor in the etiology of head and neck cancer. Cancers of the upper digestive tract (oral cavity, pharynx, and larynx, and esophagus), concurrently in the head and neck region,collectively account for approximately 10 percent of the world’s total new cancer cases. This study investigates the relationship of five oral hygiene indicators with the incidence of head and neck cancer.
Adequate knowledge about oral health and following proper oral hygiene practices have a great clinical significance. The study included countries from five continents and explored the role of oral hygiene indicators. Studies were gathered using a pooled analysis on oral hygiene and head and neck cancer from the International Head and Neck Cancer Epidemiology (INHANCE) consortium. It described the largest and most comprehensive assessment of the association between oral health and HNCs which includesoral cavity, laryngeal, hypopharyngeal, and oropharyngeal cancers.
The primary aim of the study is to determine the relationship of five oral hygiene indicators with the incidence of head and neck cancer.
The study consisted of 8,925 incident cases and 12,527 controls from 13 INHANCE case-control studies. Written informed consent was obtained from study subjects and approved by the institutional review board at each institution involved.
Associations were observed between oral hygiene indicators and HNC, independent of alcohol drinking and tobacco smoking.The five oral hygiene indicators include wearing dentures, gum disease, number of missing teeth, dental visits, and tooth brushing.
The population attributable fraction (PAF) for poor oral hygiene was identified.This depended on the oral hygiene score based on the sum of the indicators. The scores ranged from 0 to 5 with 0 being signifying the worst oral health and 5 as the best. PAF for poor oral hygiene score of less than or equal to 2 indicators signify an 8.9% risk of oral cancer and 5.4% risk of HNCs.
Poor Oral Hygiene and Tooth brushing
Trauma and inflammation are the mechanisms linking poor oral hygiene to the development of oral cancer. These mechanisms may be due to coexisting disease and negligence of oral hygiene. Frequent tooth brushing is inversely associated with the development of oropharyngeal, pharyngeal, hypopharyngeal, and laryngeal cancer.
Tooth loss is directly related to the other four oral health indicators. Having less than 5 missing teeth is inversely related to the development oforopharyngeal, hypopharyngeal, pharyngeal, as well as laryngeal cancer.
Tooth loss per se reflects poor oral health maintenance which include irregular tooth brushing and dental visits. In addition, it may result from mechanical trauma and inflammation from coexisting diseases such as diabetes and nutritional deficits. It can also be caused bygum disease and exposures to substances such as nitrosamines, tobacco, and alcohol.
Gum disease could include both gingivitis and periodontitis.It is independently associated with HNCs. Chronic diseases such as diabetes, especially if poorly controlled, could lead to gum disease. Neglected oral hygiene and maintenance as well as smoking play a role in its development.
Improperly fitted dentures could result to trauma and inflammation of the gums. These processes, in turn, contribute to receding gumsand tooth loss. Wearing dentures, however, was associated with increased dental visits for diagnosis and fitting. When adjusted for dental visits, a 20 % risk reduction was observed between wearing dentures and HNCs. It is inversely associated with laryngeal cancer.
Dental visits had a 26% relative risk reduction with oral cancer when adjusted for wearing dentures. It also had a 26% risk reduction in head and neck cancer. Moreover, frequent dental visits are associated with regular teeth cleaning and diagnoses of dental caries. It is also related to an overall better quality of life. Regular dental visits reduce the risk of orophrayngeal, pharyngeal, hypopharyngeal, and laryngeal cancers.
It is well documented that a healthy oral cavity is essential for a healthy body. Maintenance of proper oral health results in reduction of all oral diseases and cancer. Good oral hygiene is associated with lower risk of HNCs. Maintaining good oral hygiene, particularly annual dental visits and daily tooth brushing, may be protective against HNCs.
Hashim D. et al. The Role of Oral Hygiene in Head and Neck Cancer: Results from International Head and Neck Cancer Epidemiology (INHANCE) Consortium. Annals of Oncology. 2016.