Biting the lip or cheek is not a common symptom of Parkinson’s disease. If there is a temporal link to a possible lack of medication effect (‘off’ phase), or to an excessively strong effect (‘on’ phase with hypermobility), there may be a connection; if this is the case, you should seek to adjust your medication to reduce these symptoms. However, excessive movement of the tongue is unusual.
It’s possible that a lack of fluids could cause you to bite the wrong place, for example if your mouth is very dry. Drinking enough fluids can make it easier and quicker to swallow your food.
/Håkan Widner