There are two white lines on both sides of the mouth, consider that this white line should be the buccal white line, which is the occlusal line. Don’t worry, it’s not a big problem. The buccal white line is a grayish-white linear elevation appearing on the mucosa of the cheek bilaterally, a tissue reaction caused by the constant stimulation of the buccal mucosa by the teeth during chewing, which is common in adults, some noticeable and some not. The clinical characteristics of this white line correspond to the seam of the upper and lower jaw teeth when biting, and the mucosal surface outside the white line is smooth, soft and elastic. During clenching, the line bulge is located on the dentition surface and extends backward from the corner of the mouth to the front of the pterygomandibular ligament. Therefore, this is not considered a disease. It is recommended to maintain oral hygiene and avoid irritating foods, and no special treatment is needed.