Table 1.

The impact of regular dental visits on the risk of developing head and neck squamous cell carcinoma.

References	Year	Rated Factor	Type of Study	n	Risk of HNC	Description
Lissowaska et al. [29].	2003	Lack of dental care	case–control study	122 cases 124 controls	Increased (in the group with no dental care)	OR = 11.89 95% CI: 3.33–42.51
Rosenquist et al. [30].	2005	Regular dental care	case–control study	132 cases 320 controls	Decreased (in the group with regular dental care)	OR = 0.4 95% CI: 0.2–0.6
Guha N et al. [31].	2007	Lack of dental care	case-control study	2286 cases 1824 controls	Increased (in the group with no dental care)	OR = 1.61 95% CI: 1.18–2.20
Divaris et al. [32].	2010	Regular dental care	case-control study	1361 cases 1289 controls	Decreased (in the group with regular dental care)	OR = 0.68 95% CI: 0.53–0.87
Chang JS, et al. [33].	2013	Lack of dental care	case-control study	317 cases 296 controls	Increased (in the group with no dental care)	OR = 2.86 95% CI: 1.47–5.57
Ahrens et al. [34].	2014	Lack of dental care	case-control study	1963 cases 1993 controls	Increased (in the group with no dental care)	OR = 1.93 95% CI: 1.48–2.51
Hashim et al. [35].	2016	Regular dental care	case-control study	8925 cases 12,527 controls	Decreased (in the group with regular dental care)	OR = 0.78 95% CI: 0.72–0.85

OR—odds ratio, CI—confidence intervals; HNC—head and neck squamous cell carcinoma.