Oral health significantly influences overall health and has become a key factor in improving the quality of life. Oral health is especially important in adolescence as it affects the growth and development. Moreover, because healthy oral hygiene habits developed during this period serve as foundational behaviors for lifelong oral health maintenance, it is crucial to pay attention to adolescents’ oral health [14,15]. Therefore, this study aimed to explore the factors influencing adolescents’ oral health and subjective health using the KYRBS data.

Subjective health perception was better among female students compared to male students and higher among middle school students compared to high school students. Students with a high economic status and average academic performance and those who did not drink alcohol or smoke exhibited better subjective health perception. Similarly, Kim and Hyun [3] found that subjective health perception was better among female students than male students, among middle school students than high school students, and among those with a high economic status. Choi [16] also noted that lower economic status and academic performance were associated with poor health and that smoking and alcohol consumption (≤7 days) correlated significantly with subjective health. These findings suggest that socioeconomic status can lead to health disparities, highlighting the need for public health interventions such as expanding public healthcare services, enhancing health insurance for economically vulnerable groups, and providing preventive services.

In terms of oral health characteristics, adolescents with better subjective health perception tended to brush their teeth more than three times per day and brush before bed. Similarly, Seong and Lee [13] reported that those who brushed their teeth three or more times per day had better oral health. Based on this finding, they emphasized the need for oral health education to maintain a healthy oral state. Adolescents frequently consume sugary snacks and drinks, which increases the risk of dental caries, underscoring the need to reinforce tooth brushing practices and emphasize the importance of oral disease prevention [17]. Providing opportunities for continuous oral health education and motivation to change oral health knowledge and attitudes among adolescents is essential. Adolescents who used dental floss and interdental brushes reported better subjective health perception. Lee and Lee [18] found that middle school students used floss and interdental brushes more frequently than high school students. Therefore, it is necessary to educate adolescents on choosing the right oral care products for their individual oral conditions and provide direct demonstrations regarding their proper use. Adolescents who had not undergone dental sealant treatment or scaling reported better subjective health perception. Oh [19] noted that dental sealants, which prevent occlusal surface caries, are typically applied during school age and that adolescents often lack awareness about scaling. Park and Lee [20] found that gingival bleeding was more common among high school students than middle school students and that oral health deteriorated as students progressed to higher education grades. These findings highlight the need for education on the importance of scaling from an oral disease prevention perspective.

Subjective health perception was better among those who received oral health education. Previous studies have shown that middle school students are more likely to have received oral health education than high school students [13,21]. Hence, there is a need to strengthen oral health education for high school students [13]. Although they face more time constraints due to academic demands, providing opportunities for oral health education is essential to empower students to manage their health independently. Regarding oral health symptoms, subjective health perception was better when students did not experience tooth fractures, tooth pain, gingival bleeding, or bad breath. Similarly, Oh [19] reported that better subjective health perception was significantly associated with the absence of tooth fracture, tooth pain, gingival bleeding, and bad breath. Since adolescents spend most of their day at school, it is important to develop and implement oral health education programs tailored to their needs and understanding.

The predictors of subjective health included the frequency of brushing teeth on the previous day, tooth brushing before bed, using interdental brushes, receiving oral health education, tooth pain, gingival bleeding, and bad breath. The findings suggest a positive correlation between better subjective health perception and better oral health management. Good oral health behaviors established during adolescence are important determinants of oral and physical health throughout life [22].

The study limitations include the use of the 18th (2022) KYRBS that followed a cross-sectional design, rendering the data largely subjective and hindering causal inferences. Future studies should consider using objective instruments or professionally examined oral health status to conduct a more comprehensive research. Despite these limitations, the use of data from the nationally representative KYRBS provides relevant foundational data to develop policies aimed at promoting adolescent health and oral health education programs.