The Masseter muscles are the two primary chewing muscles which cover the sides of the jaw just behind the cheeks. They are responsible for clenching the jaw and grinding the teeth and are the strongest muscles in the human body. Unfortunately, they are also one of the most common locations for trigger points in the human body, which often accompany many cases of ‘bruxism’ – grinding of the teeth – and temporomandibular joint syndrome. There is also a strong connection between tension headaches and jaw muscle tension.
Botox (Botulinum Toxin A)
Patients that have easily identifiable trigger points, permanently contracted muscles, or headaches that are associated with muscle spasms are very good candidates for Botulinum Toxin A injections. Botox is the industry name for Botulinum toxin type A, which is derived from a strain of bacteria called Clostridium Botulinum. When Botox is injected into a muscle, it blocks the signals sent from the brain which tell the muscle to contract. Botox targets the muscles involved by effectively disarming them and ensuring that they do not send panic signals throughout the body. The body believes that there is no pain being experienced. Botox can help to keep the muscle relaxed for anywhere from three to six months, after which it is hoped that the muscle will be able to contract normally without pain or spasms.
Initially, the treating doctor will spend time identifying the individual trigger points, and will mark the areas with a pen. The located areas will then be sterilised with a chlorhexidine antiseptic spray and a fast acting local anaesthetic will be will injected through a small cosmetic needle.
The Botox can then be administered by one of three different ways, depending on the case. Small cosmetic needles are usually preferred, but a Stimuplex nerve stimulator or ultrasound guidance are sometimes necessary if the trigger points are more difficult to access. 100 units of Botox are usually administered, but this can increase up to 200 units depending on the affected area. The Botox is injected directly into the Masseter muscles which close the jaw.
One of the major advantages of Botox is that there is little or no recovery time, and most people feel fine and can return to their normal life immediately. The results of treatment should last around 3-6 months and the procedure can be repeated after this time.