The aim of this study is to consider the hypothesis that wearing mouthguards (MGs) from a young age helps to shape players’ habit of continuing to wear MGs as adults. In addition, we consider the mandatory rule of wearing mouthguards in the youth category on the future wearing rates of mouthguards. Eighty-five Japanese male amateur rugby players were included in this study. We examined the relationship between the wearing rates of mouthguards when participants were high school students and as adults (in 2018) using a questionnaire. Collected data were classified into categories (age, mouthguard type, and applied mandatory rule or not), and their relationships were analyzed. The wearing rate of mouthguards in high school was significantly related to the wearing rate of mouthguards in adulthood (χ2 = 12.1, p < 0.01). The mandatory rule to wear mouthguards at high school was related to the wearing rates of mouthguards as adults, but not significantly (χ2 = 3.42, p = 0.06). Participants’ mouthguard wearing rates as adults were affected by their high school wearing rates. The mandatory rule of wearing mouthguards in the youth category may be somewhat effective for improving mouthguard wearing rates; however, it is more important to provide knowledge about their importance.

The aims of the present study were to investigate the shock absorption capability and force dispersion effect of mouthguard (MG) materials using load cell and film sensors. Two kinds of MG materials, ethylene vinyl acetate and polyolefin, were chosen for this study. When impact forces of approximately 5,000 N were applied on the MG materials using a round flat-nosed rod and a bluntly pointed rod, peak intensities were measured using the load cell sensor while peak stresses and impressed stress distribution areas were measured using the film sensor. Combined analysis using both load cell and film sensors clearly showed the shock absorption properties and force dispersion effects of different MG materials with different impact object shapes. Therefore, impact analysis involving a combined use of these sensor systems was useful and reliable in assessing the shock absorption capability and force dispersion effect of MG materials.

Japan's largest platform for academic e-journals: J-STAGE is a full text database for reviewed academic papers published by Japanese societies