Mouth pieces are items that are placed in the mouth to help with speech or playing musical instruments. The term 'mouth pieces' can refer to a variety of items, such as LIPS, which is a four letter word that is one of the solutions to this crossword puzzle. Other examples of mouth pieces include trumpets, clarinets, and saxophones, which are all instruments that require a mouth piece to be played. Additionally, some people use mouth pieces to help with speech impediments, such as stuttering.