I have been getting these white lines on the the tip of my tongue lately and I don't know what they are. The tip of my tongue is sore and somewhat burns every now and then. The white lines don't stay in 1 spot, they are always in different areas, but always on the tip area. I thought maybe it was because of sugar or because I wear a mouthguard at night and I thrust my tongue into my lower teeth. I can see the identations of my teeth on my tongue. But the white areas aren't always in that area, sometimes there on the sides or top, but always the first 1/3 of my tongue. Any ideas...?