US Patent 10029144 Oral cavity function training tool

An exercise tool 1 for improving oral function inserted and used in an oral cavity includes: a base 10 inserted in the oral cavity; and a hollow bulge 20 which is made of an elastic body and protrudes from the base 10. Level difference portions 41-43 and 51-53 are provided in a vertically intermediate region of at least one of an outer surface and an inner surface of the bulge 20.