A method is provided to measure the difference of lip closure force between left and right lips and find weaknesses in left and right lips that are caused by hypoplasia, atrophy and paralysis so that such symptoms can be treated in early stages. A lip force detecting apparatus for detecting the closure force of lips includes a housing, the upper base portion and the lower base portion for lips protruding from the housing and can be pressed using upper and lower lips, the control unit respectively measures the pressing force generated when the left side of lips presses the upper base portion and the lower base portion, and measures the pressing force generated when the right side of lips presses the upper base portion and the lower base portion.
