Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 52 3 2023 03 02 500 514 Sakineh Dadipoor Social Determinants in Health Promotion Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Fatemeh Akbarizadeh Department of Oral & Maxillofacial Radiology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran Mohtasham Ghaffari Department of Health Education & Health Promotion, School of Public Health and Safety, Shahid Beheshti University of Medi-cal Sciences, Tehran, Iran Abbas Alipour Epidemiology Thalassemia Research Center, Mazandaran University of Medical Sciences, Sari, Iran Ali Safari-Moradabadi Department of Health Promotion and Education, Social Determinants of Health Research Center, School of Health, Alborz University of Medical Sciences, Karaj, Iran 2022 06 07 2022 10 25 Background: The present research aimed to assess the effects of oral health intervention programs at school level on students’ oral hygiene in developing countries. To this aim, a systematic review and meta-analysis approach was employed. Methods: The present research was done by surfing electronic databases with MEDLINE Ovid (Embase Ovid, Scopus), Web of Science from 2000 to Mar 2020. The data were collected using a standard type of data collection including specific studies to observational ones, and the data entered RevMan 2014. The eligibility criteria were individually randomized controlled trials (RCTs) or cluster-RCTs including quasi- experimental papers with oral health interventions. The RevMan 2014 package was used for a meta-analysis done through random-effects models. Results: Meta-analyses revealed statistically significant divergences in terms of knowledge (SMD 3.31, 95% CI 2.52 to 4.11; I2 = 98; P<0.001), attitude (SMD 1.99, 95% CI 0. 43 to 3.54; I2 = 99; P<0.001), behavior (SMD 4.74, 95% CI 3.70 to 5.77; I2 = 99; P<0.001), plaque index (SMD -1.01, 95% CI -1.50 to -0. 51; I2 = 97; P<0.001) and Gingival index (SMD 0. 33, 95% CI -0. 36 to 1. 02; I2 = 98; P=0.34) in the case of students who received educational interventions versus those with ordinary care. Conclusion: The present findings attested to the effectiveness of the educational interventions in improving oral health knowledge, attitudes, behaviors, and so on which can presumably contribute to a better oral hygiene, lower incidence of oral diseases, and lower costs of the treatments imposed by oral diseases. https://ijph.tums.ac.ir/index.php/ijph/article/view/28967 https://ijph.tums.ac.ir/index.php/ijph/article/download/28967/7877