My top sheet comes out of the dryer with a deep crease in top hem

Sometimes the same thing happens on shirt fronts and I learned in a sewing class at least 50 years ago that putting white vinegar or a vinegar and water mixture sprayed or sprinkled on a crease/fold and then overlaying with a white cloth and ironing does the trick to permanently take the crease out . Sometimes this happens in things like sheets when they were not cut correctly and then are pulled in the sewing process to make sides/seams "fit" when sewn.

I haven't been able to find good quality sheets in years. The top hems always end up with deep creases that won't iron out. I think it's because the fabric used is inferior. Any suggestions on a quality brand?

Try stretching the fabric lengthwise. Probably the thread was all cotton and shrunk during laundering

I couldnt get the seam out either. I cut the top seam off and rehemmed it. Worked like a charm

You are drying them to long..it also rolls up the sleeves on tee shirts if dried to long!!

I believe it is a manufacturing shortcut gone wrong.