Patient presented with long history of bruxism. Patient has had several night guards to prevent her from damaging her teeth but she continues to have temperomandibular joint pain, temporal headaches, and poor sleep. The patient was offered injections of Botox into the masseter muscle bellies to help decrease the force that the muscle can exert on the mandible which leads to her current symptoms. Care is taken to prevent over injection of the muscle which would lead to weakness and difficulty chewing. I generally begin with outlining the path of the muscle and diagram the areas of maximum masseter contraction. Injection of approximately 25 units of Botox or 60-70 units of Dysport is appropriate. It is also important to space out the injections so that the full extent of the muscle is addressed but placing injections in a more concentrated location where contraction of the muscle is most apparent. I use a 1/2 inch 30 guage needle for injections which penetrates the skin and enters the muscle belly. I have the patient contract the muscle during injections even though the site is marked so my injections are accurate. The procedure is very well tolerated and full effect of the injections will be realized in about 5 days with Botox. Additional Botox or Dysport may be injected if further weakening of the muscle is desired.