Since I started str8 shaving I have developed cracks in the corners of my mouth. I've had these before, when my lips were dry and I yawned, but these have been there a long time. I consulted a Dr. he said just keep petroleum jelly on them. I don't mind fixing the problem, but I would like to know what caused it. I was thinking maybe a change in skin pH or maybe it was my homemade aftershave splash. I really can't figure it out and my Doc just told me to shave "like a normal person". I know I didn't understand that either.