Low level laser therapy (LLLT) has been used for over two decades in the treatment of temporomandibular disorders (TMD). This book provides review of the literature evaluates the current evidence for the use of LLLT as a treatment modality in treating patients with TMD. Twenty studies were identified, Two retrospective studies and Seventeen clinical trials. These studies were evaluated and discussed. Results: All retrospective studies and nine out of the seventeen clinical trials had positive results. Studies with negative results are most likely due to insufficient dosing or improper design. Conclusion: LLLT is an alternative physical medicine modality in treating patients with TMD. State of the art dosing is suggested. More studies are needed to define the ultimate dose specific to each TMD condition. A double blind Randomized Clinical Trial titled "Dose Effect Evaluation of Low Level Laser Therapy LLLT as an Adjunctive Treatment in Patients with Myofascial Pain: A Pilot Study" done by the author is also explained in detail in this book. This book is a thesis that was submitted in partial fulfillment of the requirements for the degree of Master of Science University at Buffalo.