Evaluation of low energy level laser biostimulation at different energy densities in the treatment of temporomandibular joint irregularities: a retrospective study

Introduction and Objective: The temporomandibular joint (TMJ) is a diarthrodial joint formed by the glenoid fossa of the temporal bone and the mandibular condyle, located just anterior to the external auditory canal. Histologically, it differs from other articular surfaces in the body by being covered with fibrocartilage rather than hyaline cartilage. Joint disorders occur in cases such as unbalanced distribution of forces to the TMJ and parafunctional habits of patients. Patients' complaints in the TMJ region are often accompanied by pain, tenderness and hypertrophy in the masseter and temporal muscles. Although the symptoms developing in the muscles may be mild, they can reach to the restriction of patients' daily lives. In order to alleviate the symptoms, treatments such as drug therapy, cessation of parafunctional habits and use of intraoral appliances are applied. However, in cases of severe complaints, low level energy laser (LLEL) biostimulation can be applied to the joint and muscle area. LLEL biostimulation reduces symptoms by reducing the force of contraction in the muscles and is reported to be an effective treatment method in the literature. The biostimulation effect of LLEL is used to reduce pain, stimulate wound healing, accelerate collagen development, anti-inflammatory effect or change other biological events. The aim of this study was to evaluate the energy density that provides the highest success in the application of low-energy lasers in the treatment of temporomandibular irregularity and to contribute to the establishment of a standard protocol. Materials and Methods: This study was conducted at Karadeniz Technical University, Faculty of Dentistry, Department of Oral, Dental and Maxillofacial Surgery. The study was conducted by retrospectively analysing the files of patients who presented with temporomandibular joint disorder (TMD) and underwent LLEL treatment. Patients were divided into myalgia, disc displacement with reduction and follow-up groups. In our study, Ga-Al-As diode laser (EzLase 940, Biolase Technology, Inc. 4 Cromwell Irvine, USA) for low-level laser treatment was applied to subgroup IIa (940 nm, 1. 5 W, 90 J, pulsative), subgroup IIb (940 nm, 3 W, 180J, pulsative) and subgroup Ia (940 nm, 1.5 W, 90J, pulsative) and subgroup Ib (940 nm, 3 W, 180J, pulsative) in the myalgia group and disc displacement with reduction group, respectively. Until the treatment was completed, 9 sessions were performed 3 times a week. Age, gender, height, weight, clinical data of the patients before and 1 and 6 months after treatment were recorded. The clinical parameters evaluated were the intensity of pain felt by the patients during jaw functions, maximum mouth opening without pain, maximum mouth opening with and without physician assistance, right and left lateral movements of the jaw, protrusion movement of the jaw, clicking sound and tinnitus. All patients were followed up for six months after the treatments. In terms of treatment results, patients in each group were compared and evaluated in terms of treatment results in our study. Conclusion: According to the results of the study, DESL was found to be an effective method in reducing pain, improving jaw movements, and treating joint sounds in all subgroups of both reduced disc displacement and myalgia group. In myalgia subgroup IIa, there was no significant difference in the maximum mouth opening with and without physician assistance at all follow-up times. A significant difference was observed in the maximum mouth opening with the help of a physician when myalgia subgroup IIb and the control group were compared, and in the right lateral movement of the jaw when myalgia subgroup IIa and the control group were compared. There was no significant difference in pain reduction and other clinical parameters between the reduction disc displacement and myalgia subgroups and between the control groups.