inserts are also available, but no published peer-reviewed clinical trials have shown them to be useful. Medication Medication is the main method of managing pain in TMD, mostly because there is little if any evidence of the effectiveness of surgical or dental interventions. Many drugs have been used to treat TMD pain, such as analgesics (pain killers), benzodiazepines (e.g. clonazepam, prazepam, diazepam), anticonvulsants (e.g. gabapentin), muscle relaxants (e.g. cyclobenzaprine), and others. Analgesics that have been studied in TMD include non-steroidal anti-inflammatory drugs (e.g. piroxicam, diclofenac, naproxen) and cyclo-oxygenase-2 inhibitors (e.g. celecoxib). Topical methyl salicylate and topical capsaicin have also been used. Other drugs that have been described for use in TMD include glucosamine hydrochloride/chondroitin sulphate and propranolol. Low-doses of anti-muscarinic tricyclic antidepressants such as amitriptyline, or nortriptyline have also been described. Despite many randomized control trials being conducted on these commonly used medications for TMD a systematic review carried out in 2010 concluded that there was insufficient evidence to support or not to support the use of these drugs in TMD. In a subset of people with TMD who are not helped by either noninvasive and invasive treatments, long term use of opiate analgesics has been suggested, although these drugs carry a risk of drug dependence and other side effects. Examples include morphine, fentanyl, oxycodone, tramadol, hydrocodone, and methadone. Injections of local anesthetic, sometimes combined with steroids, into the muscles (e.g. the temoralis muscle or its tendon) are also sometimes used. Local anesthetics may provide temporary pain relief, and steroids inhibit pro-inflammatory cytokines. Steroids and other medications are sometimes injected directly into the joint (See Intra-articular injections). Botulinum toxin solution ("Botox") is sometimes used to treat TMD. Injection of botox into the lateral pterygoid muscle has been investigated in multiple randomized control trials, and there is evidence that it is of benefit in TMD. It is theorized that spasm of lateral pterygoid causes anterior disc displacement. Botulinum toxin causes temporary muscular paralysis by inhibiting acetylcholine release at the neuromuscular junction. The effects usually last for a period of months before they wear off. Complications include the creation of a "fixed" expression due to diffusion of the solution and subsequent involvement of the muscles of facial expression, which lasts until the effects of the botox wear off. Physiotherapy Physiotherapy (physical therapy) is sometimes used as an adjuvant to other methods of treatment in TMD. There are many different approaches described, but