Table 2.

Adjusted factors when evaluating the association between periodontitis and OC in the included studies.

Included studies	Adjusted factors
Shin et al. (2019)	age, sex, and smoking, alcohol intake, education level, physical activity, obesity, diabetes, hypertension, and hypercholesterolemia.
Laprise et al. (2016)	paan chewing, bidi and cigarette smoking, alcohol consumption, age, gender and number of educational years
Moraes et al. (2016)	smoking and alcohol
Tezal et al. (2009)	age at diagnosis, gender, race/ethnicity, marital status, smoking status, alcohol use, ABL, and missing teeth.
Tezal et al. (2007)	smoking and alcohol
Rosenquist et al. (2005)	tobacco smoking and alcohol consumption
Chen et al. (2021)
Chang et al. (2007)	sex, age, education, cigarette smoking (pack-year categories), betel quid chewing (pack-year categories), and alcohol drinking (frequency) sex, age, education, cigarette smoking (pack-year categories), betel quid chewing (pack-year categories), and alcohol drinking (frequency)

OC, oral cancer.