PROBLEM TO BE SOLVED: To provide a mouthpiece which suppresses the drying of the inside of an oral cavity, exhibits an effect for preventing the infection of saliva (anti-bacteriral effect and cleaning), and can be used for preventing a disease in the oral cavity such as a gum disease.SOLUTION: The mouthpiece 30 comprises: a plate-shaped coated part 40 which covers front faces of upper and lower tooth rows 10, 20 and front faces of upper and lower gum ridges 11, 21, and is sandwiched between rips 12, 22 and cheeks a holding part 50 which supports the coated part with respect to a tooth part except for a front tooth part of the upper jaw tooth row or the lower jaw tooth row and an elastic valve 70 which always forms an air passing opening 60 which penetrates the coated part at the front tooth part in the coated part, and is variable in the magnitude of an opening area oft he opening while elastically being deformed. The elastic valve has a shape in which a plurality of small pieces 71 are aligned.COPYRIGHT: (C)2013,JPO&INPIT【課題】口腔内の乾燥を抑え、唾液の感染予防(抗菌・洗浄)の効果を発揮させて歯周病などの口腔内における疾患を予防するために用い得るマウスピースを提供する。【解決手段】マウスピース30は、上下顎の歯列10、20の前面および上下の歯茎11、21の前面を覆い、口唇12、22および頬との間に挟みこまれるプレート状の被覆部40と、上顎歯列または下顎歯列のうち前歯部を除いた歯部に対して被覆部を保持する保持部50と、被覆部のうち前歯部に臨む部位に被覆部を貫通する空気通過用の開口部60を常時形成するとともに弾性的に変位して開口部の開口面積の大きさを可変自在な弾性弁部70と、を有している。弾性弁部は、複数の小片71を配列した形状を有している。【選択図】図1
