Laser Therapy for Temporomandibular Joint Dysfunction (TMJ)
Temporomandibular joint disorder (TMD) is a broad term for an array of clinical problems that affect the masticatory muscles (the muscles in the jaw used for chewing food), the temporomandibular joint, and other associated structures. The temporomandibular joint is the hinge that connects your jaw bone to your skull and allows for the up and down and side to side motions of your mouth. Although it is difficult to pinpoint the direct cause of temporomandibular joint (TMJ) pain and dysfunction, many causes can be narrowed down to trauma, osteoarthritis, and stress.
Common symptoms of TMD include pain in the sides of the face, jaw joint area, neck, shoulders, and discomfort in and around the ear. It can also cause popping, clicking, or grating sounds when opening or closing the jaw, a feeling of tiredness in the face attributed to muscle fatigue, discomfort while chewing, or swelling of the face. TMD can additionally be attributed with other uncomfortable symptoms such as headaches, dizziness, tinnitus, toothaches, and neck pain.
Those suffering from TMJ dysfunction typically have constricted blood supply to the jaw and surrounding muscles. This results in cellular waste buildup and prevents oxygen from reaching cells in order to support the healing process and reduce inflammation. There are also chemical changes in the muscle (increase in inflammatory chemical buildup due to muscle fatigue), and muscle soreness and spasm. Thankfully, low level laser therapy (LLLT) can be incredibly beneficial in treating dysfunction of the temporomandibular joint to ease discomfort, pain, inflammation, and swelling.
LLLT uses a process called photobiomodulation to interact with various intracellular biomolecules. One of the major effects of these chemical reactions is the increase in the production of ATP, the body’s chemical form of energy. An increase in ATP results in improved cellular metabolism, DNA production, and cellular replication for the replacement, regeneration, and repair of damaged cells. Low level laser therapy also increase blood flow to the damaged joints and tight, painful muscles of the jaw. It does this through processes called angiogenesis and neovascularization, the formation of new capillaries and other blood vessels.
LLLT increases the amount and functionality of macrophages and neutrophils, which remove damaged cells and breaks the cycle of chronic inflammation. It also decreases the amount of oxidative stress around the joint which promotes cell survival and reduces cellular damage. Anti-inflammatory cytokines are increased in response to light therapy and prevent the stalling in the inflammatory phase and promote tissue repair. There is also a decrease in pro-inflammatory cytokines and prostaglandins which result in decreased pain.
In a study analyzing the effect of low level laser therapy in the treatment of temporomandibular disorders 45 people suffering from symptoms for over 6 months were treated. They were treated twice a week for 5 weeks. Results showed that LLLT improved mandibular range of motion and a significant reduction of pain.
Another study concluded that LLLT can be considered as a useful method for the treatment of TMD related pain, especially in the long term.
A systematic review analyzing 13 different studies examining LLLT for TMD showed that Low Level Laser Therapy was effective in the reduction of pain in the temporomandibular joint by producing a dose specific anti-inflammatory effect on the irradiated joint capsule.