Effectiveness of Low-Level Laser Therapy (LLLT) Versus Orofacial Physical Therapy for Temporomandibular Dysfunction. a Randomized Controlled Trial

In the last 30 years, many nonsurgical therapies have been suggested for the treatment oftemporomandibular disorders (TMD), including physical therapy, pharmacologic therapy,occlusal splints, occlusal adjustment, acupuncture, and low‐level laser therapy (LLLT).(1) The main objective of all these treatment modalities is to reduce symptom intensity,thereby improving the function of the masticatory system and adjacent structures.(2)Signs and symptoms of TMD are present in 86% of the population, being more frequent amongwomen, also related to dental occlusion and emotional stress. Are considered signs:limited mouth opening, joint sounds and deviation of the mandible to one side duringopening and closing, muscle spasm, pain reflex, impaired joint motion, crepitus, headacheand hearing disorders. Otologic symptoms are represented by decreased hearing, vertigoand tinnitus, which can be related to the ontogenetic and anatomical relationship betweenthe middle ear and masticatory structures.(3) Among nonsurgical treatments, LLLT hasincreased in interest in the last few years, probably due to its ease of use incombination with reports of positive effects on pain alleviation. (4) LLLT is anon‐thermal type of light, which causes internal changes in cells and tissues, leading todifferent types of metabolic activations. (5) These include stimulation of the cellularrespiratory chain and increase in vascularization and fibroblast formation which havebeen suggested to play an important role in the analgesic effect of LLLT. Despite thefact that there is no universally accepted theory to explain the mechanism of either"laser analgesia" or "laser bio stimulation,"(6) LLLT can be expected to promote someanti‐inflammatory effect and pain relief in painful and dysfunctional joints andmuscles.(7) The most clinically used LLLT include the helium‐neon laser (632 nm He‐Ne)and infrared laser, as diode‐gallium‐arsenide (904 nm Ga‐As) orgallium‐aluminium‐arsenide (830 nm Ga‐Al‐As). The mechanism of pain relief via mid‐lasertherapy is not clearly understood and several theories have been suggested. One theoryconsiders the analgesic effect to be a consequence of the reduction of levels ofprostaglandin E2 (PGE2 ), which is one of the most important proinflammatory mediators.This theory is based on in vivo and in vitro findings of a reduction of PGE2 both incultures of ligament cells and in the joint capsule of animals after laser exposure. ThePGE2 reduction probably derives from the inhibition made by laser radiation ofcyclooxygenase‐2 (COX‐2), the enzyme involved in the synthesis of PGE.(8, 9) Anothertheory takes into account the effect of laser therapy on neuronal cells: The effectinvolves the possible selective inhibition of nociceptive signals16 and themicrocirculation regulation; this action could interrupt the origin and development ofpain and thus could provide analgesic effects.17,18 The magnitude of the laser effectseems to depend on the wavelength and dosage of the laser light.11 It has been reportedthat reduction of PGE2 could be observed within a range of dose between 0.4 and 19 J andwithin a range of power density between 5 and 21.2 mW/cm2 . (10)Temporomandibular disorders (TMDs) are probably the most common cause of pain ofnon‐dental origin in the maxillofacial area. The category of TMDs embraces a number ofclinical problems related to masticator muscles, temporomandibular joint (TMJ) andassociated structures, or both. (11) Such disorders are characterised by pain, jointsounds, and restricted mandibular movement. The incidence of TMD ranges from 40 to 75 %in general populations and approximately 65 % of affected patients experience associatedpain. This great number of patients is treated using different modalities, depending onthe aetiology of signs and symptoms. Conservative, rather than aggressive andirreversible, treatment is preferred to relieve symptoms, diminish pain, and re‐establishfunction. (12, 13) As the aetiology of TMD is multifactorial, available treatments areextensive and diverse, including the use of occlusal splints, low‐level laser therapy(LLLT), and transcutaneous electrical nerve stimulation, among many others. Given thatbetter therapeutic results (i.e. pain relief ) are obtained with the combined use ofmodalities, several recent studies have examined the use of LLLT to reduce TMD pain andpromote bio augmentation effects. (14) The LLT has demonstrated an ability to assist inthe symptomatic treatment of pain, providing a considerable degree of comfort to thepatient after application. The great advantage of laser applications in the treatment ofTMD is that it is a non‐invasive therapy, with low cost, and currently has being widelyused in dental practice, reducing the demand related to the surgery or the use of drugsto treat relief pain and tissue regeneration.(15) The application of laser therapy in TMDpatients has demonstrated an ability to relieve pain in few minutes after application,promoting well‐being significant. However, LLT is an adjuvant treatment in pain relief byits analgesic action, which allows the patient's return to daily chores, providingcomfort and better quality of life.(16) The G1 group was randomly divided into 7therapeutic groups in which the therapy was carried out for 10 days: magneto stimulation(T1), magnetoledotherapy (T2), magnetolaserotherapy (T3), manual therapy‐ positionalrelease and therapeutic exercises (T4), manual therapy ‐ massage and therapeuticexercises (T5), manual therapy ‐ PIR and therapeutic exercises (T6), self therapy ‐therapeutic exercises (T7).G2 was given LLLT. (17) Most people can open their mouth 35 to55 millimeters (1.4 to 2.2 inches), which is about the width of 3 fingers (see Figure 2).Figure 2. Normal width of an open mouth Your jaw is made up of a pair of bones that formthe framework of your mouth and teeth.(18)This study will investigate if Low‐Level Laser Therapy (LLLT) is more effective thanOrofacial Physical Therapy for treating Temporomandibular Dysfunction. By conducting arandomized controlled trial, it aims to fill gaps in current knowledge, improve TMDtreatment options, and enhance patient outcomes.