There's a raised line on the inside of the mouth.

In fact, there is no special name for the inner wall of the mouth. Let's default it to the inner side of the lips and the inner side of the buccal mucosa. In fact, it is the cheek. It is relatively smooth and generally does not grow a separate flesh bulge. There are several cases, a bilateral symmetrical flesh bulge, generally in the buccal mucosa opposite to the upper sixth tooth, feels soft, the color is similar to the surrounding, usually the opening of the parotid duct, sometimes it is more obvious, sometimes relatively flat, this is a normal structure, its characteristics are symmetrical on both sides; if the inner side of the lower lip is swollen