Most people can open their mouths at least 4 centimeters, but victims of OSF can only open theirs 1-3 cm, depending on the severity of their condition. Once this opening is reduced to under 2 cm, it becomes difficult to use a toothbrush, leading to problems with oral hygiene and gingivitis.
一般人口腔可張開 4 公分以上，但口腔硬化患者，輕者張開 3 公分，重者只能張開 1 ~ 2 公分，而一旦張口幅度小於 2 公分，牙刷難以進入，將導致口腔不衛生、牙周病等問題。