Had a white line on inside cheek few days ago. still there but has almost gone away. now i have sore throat & it hurts to swallow. anything serious?

Linea Alba: White linear horizontal line of cheeks is called "linea alba"....Latin for white line and is a result of bruxing. May also notice scalloping of lateral borders of tongue. If this is the case and does not resolve....Use night guard. Often associated with headaches, tm joint pain, neck and upper back pain and then should use soft appliance.

Need to see your doc: The white line inside the cheek that is almost gone now may not be anything serious. The sore throat and pain with swallowing suggests a possible infection. You should see your doctor to determine the cause and have the appropriate treatment prescribed if indicated.