Which do you think is dangerous, Left or Right?
Left one is white, dented at the center and soft, and located inside of the cheek.
Right one is white, raised and hard, and located under the tongue.
The answer is Right.
Left one is a canker sore. It is painful to touch but gets better within 1 to 2 weeks.
Right one is a tongue cancer. It is not painful to touch but causes symptoms like not speaking clearly, bad breath, dull taste, developing into whole the tongue as shown below.
If you find white and raised boil, and it doesn't get better for a while, it is recommended to consult with an oral surgery office.