The goal of this clinical trial is to compare occlusal splint and arthrocentesis in patients with disc displacement with/without reduction. The main question it aims to answer are:

• Is there a more effective treatment for this cases?

Participants will answer a questionary about pain and functional limitations.

Researchers will compare Group 1(occlusal plate) and Gruoup 2 (arthrocentesis) to see if there is pain reduction and functional improvement in patients with disc displacement with/without reduction

Introduction: Temporomandibular joint disc displacement is a disorder in which the articular disc is anteriorly displaced from its correct position in relation to the mandibular condyle and mandibular fossa. Traditionally, the initial treatment of disc displacements involves several conservative measures, among them, the stabilizing interocclusal splint. However, in cases where there is associated opening limitation, such as intermittent lock and closed-lock, arthrocentesis has been suggested as another initial treatment modality due to its faster effect in preventing disease progression to a more advanced stage, in addition to reducing the chances of pain chronicity and central sensitization. Objectives: The present study aimed to compare and analyze the effectiveness and benefits of performing arthrocentesis as the initial treatment in patients with DDWR with intermittent lock and in patients with DDWoR, compared to the stabilizing interocclusal splint. Additionally, it had as secondary objectives to characterize the sample according to demographic, systemic, local and psychosocial factors in both groups and to correlate the clinical characteristics of the included patients with the imaging findings of the MRI scans. Methods: A randomized, prospective, longitudinal pilot study was performed. The sample was obtained by convenience from a demand through consultations and referral, among patients treated at the Oral and Maxillofacial Surgery Service of HCFMUSP, from June 2021 to July 2023. Patients with diagnoses of: DDWR intermittent lock and DDWoR with opening mouth limitation. Study patients underwent an initial assessment using a clinical questionnaire (DC/TMD) and underwent an initial TMJ MRI. Then, they were randomly divided into two groups according to the treatment to which they would be submitted: stabilizing inter-occlusal splint (group 1) or arthrocentesis (group 2). After treatment was instituted, patients were evaluated at 1, 2, 3 and 6 months regarding clinical parameters of pain, functionality and psychosocial status.

Inclusion Criteria:

• Patients at least 18 years old;
• Diagnosed with disc displacement with reduction with intermittent block or disc displacement without reduction;
• Availability of clinical follow-up for 6 months.

Exclusion Criteria:

• Pregnant patients;
• Patients undergoing conservative or invasive interventions to treat TMD in the last 6 months;
• Inability to use a stabilizing occlusal splint;
• Presence of toothache, neoplasms or medical contraindication for study participation.