Teeth clenching during exercise is important for sports performance and health. Recently, several mouth guard (MG)-type wearable devices for exercise were studied because they do not disrupt the exercise. In this study, we developed a wearable MG device with force sensors on both sides of the maxillary first molars to monitor teeth clenching. The force sensor output increased linearly up to 70 N. In four simple occlusion tests, the trends exhibited by the outputs of the MG sensor were consistent with those of an electromyogram (EMG), and the MG device featured sufficient temporal resolution to measure the timing of teeth clenching. When the jaw moved, the MG sensor outputs depended on the sensor position. The MG sensor output from the teeth-grinding test agreed with the video-motion analysis results. It was comparatively difficult to use the EMG because it contained a significant noise level. Finally, the usefulness of the MG sensor was confirmed through an exercise tolerance test. This study indicated that the developed wearable MG device is useful for monitoring clenching timing and duration, and the degree of clenching during exercise, which can contribute to explaining the relationship between teeth clenching and sports performance.

Background/Aim: Dental trauma may occur in school settings and it can impact patients' quality of life. Analysis of the occurrences of dental trauma is essential in identifying preventive methods. There are numerous reports of such accidents but most are quantitative analyses with limited data. The aim of this study was to extract information on the mechanisms of injuries that leads to prevention by performing a qualitative analysis of the occurrence of dental trauma.

Background/Aim Sports mouthguards are effective devices that prevent dental trauma in sports activities. Players should change mouthguards on a regular basis because of thickness reduction and shape deformation. However, there is no guidance regarding the best timing to change mouthguards. The aims of this study were to analyze the thickness change and deformation of mouthguards after 2 years of use in Bangladesh field hockey players and to consider appropriate evaluation criteria. Material and Methods Fifty‐seven field hockey players belonging to the Bangladesh Sports Education Institute participated in this study. Participants were provided with double‐layered mouthguards made of polyolefin‐based material using a vacuum‐forming machine. Mouthguards were fabricated using 2‐mm‐thick sheet as the first layer and 3‐mm‐thick sheet as the second layer. Players used the mouthguards for 2 years. Before and after using the mouthguards, the thicknesses of nine areas were measured. In addition, the lengths of five areas were used to analyze shape deformation. Results After 2 years, the thicknesses of all measured areas had significantly reduced, and the lengths had significantly increased. Thickness reduction of the posterior‐occlusal and anterior‐incisal areas and deformation of the posterior‐buccal and posterior‐palatal areas were significantly larger than those in other measured areas. Conclusions Mouthguards should be changed on a regular basis to minimize thickness reduction and deformation. Occlusal and incisal thickness and length of the buccal‐posterior area and the palatal‐posterior area are factors to be considered in establishing guidelines regarding the timing of mouthguard change.

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.

Sports mouthguards (MGs) can reduce the risks of sports-related oral injuries. The aim of this study was to fabricate a composite photopolymer with shock-absorbing properties suitable for use in 3D-printed MGs. By using a commercial, flexible, rubber-like photopolymer as matrix and a commercial rigid simulated polypropylene photopolymer as a reinforcement material, five composites with different Shore A hardness levels were fabricated. Furthermore, four laminated materials were prepared to assess the improvement effects associated with adding a rigid outer layer. The five composites and four laminated materials were evaluated in terms of their shock absorbing capabilities via a steel ball drop impact test along with two types of conventional mouthguard materials. The rubber-like photopolymer composite material compounded with the rigid photopolymer with a Shore A hardness of 50 showed excellent shock absorbing capabilities that were compatible with conventional mouthguard materials, suggesting that this shock absorbing photopolymer composite is a candidate material for 3D-printed sports MGs. If the commercial flexible rubber-like photopolymer is to be applied alone without reinforcement, laminating a rigid photopolymer on the outer surface may be an effective means of improving the shock absorption capabilities of such a MG. We succeeded in fabricating a prototype of a doublelayered mouthguard with these composite materials using a 3D digital dental workflow.