Oral health knowledge and oral hygiene practices among public secondary school students in Enugu State, Nigeria: a cross-sectional study

Oral health is a critical component of public health, influencing general health, quality of life, and educational outcomes. Adolescents in low- and middle-income countries remain vulnerable to oral diseases due to limited knowledge and poor hygiene practices. This study assessed oral health knowledge and oral hygiene practices among public secondary school students in Enugu State, Nigeria. A cross-sectional survey was conducted among 504 public secondary school students selected using multistage sampling from six educational zones in Enugu State. A structured, pretested questionnaire assessed oral health knowledge (10 items; true/false) and oral hygiene practices (16 items; 4-point Likert scale). Data were analyzed using descriptive statistics (frequencies, percentages, means, standard deviations) and inferential statistics (chi-square, independent t-test) at α = 0.05. Reliability was good (knowledge: r = 0.83; practices: Cronbach’s α = 0.92). The mean age of participants was 14.8 ± 2.1 years (range 10–20). Overall, 68.9% of students demonstrated high oral health knowledge, and the mean oral hygiene practice score was 2.94 ± 0.43 (good practice category). For the overall knowledge category (high ≥ 60% vs. low/moderate < 60%), male (53.8%) and female (54.2%) students had similar proportions of high knowledge, with no significant gender difference (χ²=0.008, df = 1, p = 0.929; Cramer’s V = 0.004). Class level was significantly associated with knowledge (χ²=6.10, df = 1, p = 0.014; Cramer’s V = 0.110), with senior students (59.2%) showing better knowledge than junior students (48.4%). Location was significantly associated with knowledge (χ²=11.86, df = 1, p = 0.0006; Cramer’s V = 0.153), with urban students (59.7%) showing better knowledge than rural students (43.6%). Oral hygiene practices did not differ significantly by gender (t = 1.307, p = 0.192; Cohen’s d = 0.12) but differed by class level (t = 2.514, p = 0.012; Cohen’s d = 0.22) and location (t = 4.278, p = 0.000; Cohen’s d = 0.38). Poor practices included infrequent dental visits (mean = 2.38 ± 1.27) and improper chewing stick use (mean = 2.44 ± 1.23), particularly among rural students. Public secondary school students in Enugu State have high oral health knowledge and good oral hygiene practices. However, rural students and junior students require targeted interventions. Regular school-based oral health education and integration of oral hygiene into the curriculum are recommended.