A muscle relaxant is a drug that affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasms, pain, and hyperreflexia. Muscle relaxants in dentistry are often used in treating temporomandibuar joint disorders. A temporomandibular disorder (TMD) is a very common problem affecting up to 33% of individuals within their lifetime. TMD is often viewed as similar to musculoskeletal disorders of other parts of the body, therefore the treatment often involves similar principles as other regions as well. This review article includes brief description of commonly used muscle relaxants in dentistry, that describes mechanism of action, metabolism, dosage and side effects of the drug.