MATERIAL AND METHODS: Thirty national rugby players received custom-fitted mouthguards. Questionnaire responses and speech recordings were collected before mouthguard use and at various intervals after using mouthguards: immediately, 1 week, 2 month, and 6 months. Spectrographic analysis was performed to measure voice onset time (VOT) for /p, b, t, d/ phonemes. Questionnaire responses were assessed with Friedman's test, while VOT changes were examined using one-way repeated measure analysis of variance.