A 19-year-old patient complains about pain in the submental part of mandible. The day before he got a trauma. Objectively: there is a slight swelling of tissues in the mental area. The mouth can be opened widely enough. All the teeth are intact. Mucous membrane is edematic in the region of central incisors, it bleeds slightly. In this region mobility of mandible fragments is present. Occlusion is undisturbed. What splint should be chosen by the dentist?