A population-based, matched case–comparison study was undertaken in 30 schools in two Ontario communities to measure the impact of dental trauma on quality of life (QoL) in Canadian school children. Dental hygienists screened 2422 children aged 12–14 years using the dental trauma index, the decayed, missing and filled teeth index (DMFT) and the aesthetic component of the index of orthodontic treatment needs (AC-IOTN). Cases (n = 135) were children with evidence of previous dental trauma. Controls (n = 135) were classmates matched for age and gender. Oral-health-related QoL was assessed using mailed Child Perception Questionnaires (CPQ11-14) completed by all children. Data were analyzed using simple and multiple conditional logistic regressions after adjusting for DMFT and AC-IOTN, CPQ11-14, overall impact and item-specific impacts. Approximately 64% of injuries were untreated enamel fractures and just over 30% were previously injured restored teeth. Untreated children experienced more chewing difficulties (P = 0.026), avoided smiling (P = 0.029) and experienced affected social interactions (P = 0.032) compared with their non-injured peers. When treated and non-injured groups were compared, the only statistically significant effect was difficulty in chewing (P = 0.038). Injured children who were untreated experienced more social impact than their non-injured peers. Restoration of injured teeth improved aesthetics and social interactions but functional deficiencies persisted as a result of periodontal or pulpal pain.