PURPOSE: A mouthpiece for medical treatment is provided to prevent damage to teeth by forming a tube insertion hole at a side of a central penetration hole. CONSTITUTION: An upper insertion groove(10) is formed at an upper surface of a mouthpiece. A lower insertion groove(20) is formed at a lower surface of the mouthpiece. A front surface unit(30) is located on a front surface of the upper insertion groove and the lower insertion groove. A rear surface unit is located on a rear surface of the upper insertion groove and the lower insertion groove. A central penetration hole(50) passes through a space from the front surface unit to the rear surface unit.
