Teeth grinding and jaw clenching (also known as bruxism) is a common problem that often happens during sleep, while concentrating or under stress. Most people who grind their teeth or clench their jaw are not aware they are doing it. Common symptoms include headaches, ear pain, pain and stiffness in the jaw (temporomandibular joint), wearing of the teeth, increased tooth sensitivity and broken teeth. Frequent grinding and clenching results in the enlargement of the masseter muscles, the main muscles involved in teeth grinding and clenching. The masseters sits over the jaw and can be felt when clenching the back teeth. Botulinum toxin or ‘Botox’ injections can be used to safely and effectively weaken the masseter muscle, reduce teeth grinding and jaw clenching, thereby improving associated symptoms.