Grinding and clenching of teeth is called Bruxism and it can cause not only cracking and chipping of teeth, but soreness in jaw joints, headaches, and neck, shoulder and back pain. It mostly occurs during sleep and you may not even be aware you are doing it. The force is much greater than when you are awake, which is way it can cause so much damage.
If you are experiencing these symptoms, a custom fitted night guard or bite splint can manage bruxism. They are made from acrylic and are worn at night to absorb the force of grinding and clenching, and thus alleviating the associate symptoms.