Objectives: To investigate the frequency of use of mouthguards among a representative sample of Ontario schoolchildren, the type of mouthguard most commonly used and reasons for noncompliance during sporting activities.

Materials and Methods: A population-based, matched case–control study was undertaken in a total of 30 schools in 2 suburban Ontario communities. Dental hygienists trained in the use of the Dental Trauma Index screened 2,422 children 12 to 14 years of age. Of 810 children identified as potential cases (with evidence of dental trauma) and controls (no dental trauma), 270 responded to a mail survey (135 cases and 135 age- and sex-matched controls). The children with dental injuries provided information such as the age at which the injury occurred and the setting and causes of the injury. Children from both case and control groups answered questions concerning use of mouthguards during sports. Parents provided demographic and other information.

Results: Only 5.5% of children wore mouthguards for school sports, and 20.2% wore protection in league sports. Of those who wore mouth protection, 48.2% wore boil-and-bite mouthguards and 21.4% wore stock-type mouthguards; only 30.4% wore professionally made, custom mouthguards. This high proportion of ill-fitting mouthguards was the major contributor to the commonly perceived problems of speech, breathing discomfort and poor appearance associated with mouthguard use. Boys were 1.52 times more likely to wear mouthguards than girls. Data on history of dental trauma and regularly visiting a dentist were not related to mouthguard use. The single most important predictor of mouthguard use was parents who had private dental insurance (p = 0.02), followed by having a family dentist (p = 0.16).

Conclusion: Mouthguard use was very low in both school and league sports in this sample of Ontario schoolchildren, and the largest proportion of those who wore mouth protection used generic products rather than custom-fitted mouthguards. Lack of parental or coaching advice on mouthguard usage and peer beliefs about esthetics and function were the main reasons for noncompliance.