I have these small thin white lines on my inner cheek i'm really worried it might be mouth cancer ? it's not a line that goes across my cheek but small tiny lines all around my inner cheek

White lines: There are many causes for small white line on your cheek. Do you have pain, sensitivity, swelling? How long have they been there? The best thing for you to do is tell your parents or guardian about this and have a dentist check the area. The chance that this is cancer is extremely low, but there are other conditions that would need treatment .Good luck.

Cheek ridging: are the signs of active bruxism or habitual grinding of the teeth. See your dentist for a night guard fabrication.

Unlikely is cancer: See oral surgeon or ENT doc if you have any of these symptoms: Persistent mouth sore, persistent mouth pain, a lump or thickening in the cheek, a white/red patch on the gums, tongue, tonsil, or lining of the mouth, a sore throat, hoarseness or feeling that something is caught in the throat that does not go away, difficulty swallowing/chewing.