Lemon drops will cause that "gland" feeling if they are blocked. However, I believe that you would be experiencing more pain than numbness.from the parotid glands. I would also check into the possibility of TMJ (Temperomandibular Joint Dysfunction), which does rarely cause this--we are prone to weird stuff. https://www.williamssquaredental.com/services/general-dentist/general-dentistry/tmd#:~:text=Rarely%2C%20TMJ%20will%20cause%20numbness,resulting%20in%20loss%20of%20feeling.