RESUMO
Custom-made mouthguards are widely used by athletes during training and sporting events for the prevention of oral injuries. However, even though the prevalence of dental injuries in children in the primary or mixed dentition stages is high, few reports have focused on mouthguard use for such cases due to the difficulties associated with adapting them as teeth are lost and replaced. This report presents a case of a Japanese boy in the mixed dentition stage with a custom-made mouthguard. For fabrication, self-curing acrylic resin was used to fill portions of a working model to keep space for the later eruption of permanent teeth. However, adjustment was necessary when gingival swelling occurred in association with maxillary canine eruption, after which refabrication was necessary. Regular management of a custom-made mouthguard by the attending dentist is important for children in the mixed dentition period, especially during maxillary canine eruption, which causes drastic dentition changes. In the present case, custom-made mouthguards were fully effective based on the prediction of changes in the dentition and with regular dental management.