Hello..primarily dont get panic by the line in mouth.It is normal finding which is called linea alba occuring at plane of occlusion.

Hi, What you observed is a common finding and most likely associated with pressure, frictional irritation, or sucking trauma from the facial surfaces of the teeth. It may be found in individuals who chew tobacco, and may be mistaken for a lesion requiring treatment. It presents an asymptomatic, linear elevation, with a whitish colour, at the level of the occlusal line of the teeth. However the red patch seems like the ulcer/abration. it would most likely heal up. However, do monitor it , if it stays or increases in size, do get a dental examination performed.

This condition is called Linea Alba and it is an absolutely normal, benign condition which does not cause any symptoms, nor does it have the tendency to cause any problems in the future..... Regards.....