Why do people with really bad teeth insist on walking around with their mouths hanging open?
I ask this because I have seen a number of people today that would make British people say "I say, you have some messed up teeth."
I would like to suggest that if you have several missing teeth up front, teeth that go in opposing directions or are arranged shark-like in multiple rows, please keep your mouth shut. At least cover it up with your hand or something. Have some respect for the rest of us who just ate.
I have found it helpful to do the stretching exercises my physical therapist recommends. Do some core strengthening exercises, such as the ones highlighted at The Mayo Clinic. By keeping your core strong, your back won't put itself in a position to cause that sciatica pain you are having.