A mouthguard able to be shaped in the mouth is disclosed. The mouthguard comprises an adaptable material and a non-adaptable skeleton frame (21, 22) at least partially covered by the adaptable structure. The mouth guard also comprises a removable pallet (33) consisting of a non-adaptable material which is dimensioned and positioned so that a ventilation space and the presence of sufficient material at the incisor-canine area are maintained during fitting. The pallet (33) forms a plug to prevent a breathing opening from collapsing when the adaptable structure is formed about the user&rsquos teeth and is subsequently removed.
