Objectives: To analyze the change in pattern of plaque accumulation on buccal and occlusal surfaces of permanent teeth and associated variables in a cohort of 4,468 children examined on a yearly basis between the ages of 7 and 12 years. Method and Materials: Oral hygiene level on buccal surfaces was assessed using the Plaque Index of Silness and Loe; for occlusal surfaces, a simplified version of the index as described by Carvalho et al was used. Data on oral health habits were collected using questionnaires completed by the parents and by the school health care center. Multiple ordinal logistic regression models using first-order generalized estimating equations were fitted to estimate population average effects taking into account the correlated structure of the data. Results: Girls brushed significantly more frequently than boys (as reported by the parents) and presented with significantly less dental plaque. In all survey years, starting to brush at a young age, no daily consumption of sugar-containing drinks, and brushing at least twice a day were significantly associated with lower plaque accumulation scores. Parental help did not seem to influence the accumulation of occlusal plaque, but it did influence the amount of buccal plaque on incisors and premolars at older ages. The presence of sealants was significantly associated with less dental plaque. Conclusion: Regarding future policies for preventive strategies in schoolchildren, help with brushing at older ages can be recommended. Application of sealants can be encouraged, but further research is needed to confirm whether the presence of sealants improves oral cleanliness. Keywords: dental plaque, dietary habits, longitudinal analysis, oral hygiene habits