Background:
Smoking is more harmful to the physical health of adolescents than it is for adults. The demand for studies on electronic cigarettes as a substitute for tobacco has increased, but there is a lack of research on its harmful effects on the oral health. Therefore, we investigated the characteristics of conventional cigarette smoking, electronic cigarette use, and the dual use among adolescents and examined the relationship between oral health factors according to smoking patterns.

Methods:
The subjects of this study were 65,528 adolescents who completed a questionnaire of the 12th online survey of the youth health behaviors(2016). The types of smoking were analyzed by conventional cigarette smoking, electronic cigarette use, and non-smoking. A chi-square test and logistic regression analysis were performed.

Results:
There were significant differences in general characteristics such as gender, grade, school type, scholastic performance, location, perceived socioeconomic status, and drinking status according to type of smoking. There were significant difference in the number of brushing days, oral hygiene auxiliary products and treatment, and subjective oral health awareness. There was a significant difference also in oral disease symptoms.
The relationship between type of smoking and oral health was as follows: "Chipped or broken tooth", "Tooth pain when eating", or "Aching or throbbing in tooth",it was significantly higher in dual users and conventional cigarette only smoker, and it was higher in dual users in conventional cigarette only smoker.

Conclusions:
It was found that there was a difference in oral health effects according to the type of smoking. Tailored education programs and policies should be developed to promote oral health and prevent smoking in adolescents.