Comparison of Intra-Articular Methylprednisolone Acetate and Lidocaine Hydrochloride Injection Versus Arthrocentesis in Temporomandibular Joint Arthritis Management

The primary objective of this study is to compare **pain relief** achieved through temporomandibular joint (TMJ) intra-articular cortisone injection versus arthrocentesis in the management of clinical arthritis of the TMJ. This comparison is clinically relevant as it aims to determine the more effective treatment modality for alleviating pain associated with TMJ arthritis, which can significantly impact patients' quality of life.

Secondary objectives include:

• Evaluating maximum mouth opening following TMJ arthrocentesis versus cortisone injection at 1, 3, and 6 months post-treatment, which is important for assessing functional outcomes.
• Investigating whether psychosocial factors influence treatment outcomes, providing insights into the holistic management of TMJ arthritis.
• Determining the impact of degenerative bone changes in the TMJ on treatment outcomes concerning pain relief, which could guide personalized treatment strategies.

The clinical trial focuses on individuals diagnosed with **arthritis of the temporomandibular joint** (TMJ). The study population includes both male and female participants aged 18 years and older. Participants are required to have clinical arthritis in one or both TMJ joints and must be able to understand Swedish both orally and in writing. The trial does not target a vulnerable population. Participants have been informed about the condition and treatment involving postural exercises. The sponsor has not provided information regarding the total number of participants in the study.

The clinical trial is designed to evaluate the efficacy of intra-articular corticosteroid injection compared to arthrocentesis in managing **arthritis of the temporomandibular joint**. This study is a **randomized controlled trial** and is categorized as a phase IV trial, indicating it is a post-marketing study to gather additional information on the treatment's effectiveness. The trial is expected to commence on May 1, 2024, and conclude by May 1, 2026, with the primary objective of assessing pain relief using a 100 mm Visual Analogue Scale (VAS) at baseline, and at 1, 3, and 6 months post-treatment.

Participants will be involved in the study for a maximum of six months, with the inclusion criteria requiring individuals to be 18 years or older, have clinical arthritis in one or both temporomandibular joints, and be able to understand Swedish both orally and in writing. Written consent is mandatory for participation. The trial will exclude any participants who do not meet these criteria. The study will involve several visits, starting with a screening visit to confirm eligibility, followed by treatment visits, and subsequent follow-up visits at 1, 3, and 6 months to assess primary and secondary endpoints.

The secondary endpoints include measuring the maximal mouth opening in millimeters and evaluating psychosocial factors through questionnaires such as the Patient Health Questionnaire (PHQ-9 and PHQ-15), GAD-7, and PCS. Additionally, the presence of degenerative bone changes will be assessed by an oral radiologist. Participants may be withdrawn from the study if they experience adverse effects or if they choose to withdraw consent. The trial will utilize **methylprednisolone acetate** and **lidocaine hydrochloride** in a suspension for injection as the test product, with **paracetamol** tablets serving as a comparator. The study aims to provide comprehensive data on the effectiveness of these treatments in managing temporomandibular joint arthritis.

The clinical trial involves the administration of **Depo-Medrol cum Lidocain**, a **suspension for injection** containing **methylprednisolone acetate** and **lidocaine hydrochloride**. This pharmaceutical product is manufactured by Pfizer Oy and is authorized for use in Finland. The suspension is administered via **injection** with a maximum daily dose of 1 ml, and the treatment period is limited to 2 days. The active substances are of chemical origin, and the product is not formulated for pediatric use. The trial aims to evaluate the efficacy of this corticosteroid injection in managing clinical arthritis of the temporomandibular joint.

As a comparator treatment, **Panodil 500 mg tabletter** is utilized, which contains the active substance **paracetamol**. This product is a **film-coated tablet** manufactured by Haleon Denmark APS and is authorized in Norway. The tablets are administered **orally** with a maximum daily dose of 4 grams, and the treatment period extends up to 3 days. The active substance is of chemical origin, and the formulation is not intended for pediatric use. This comparator serves to evaluate the pain relief efficacy against the experimental treatment.

An auxiliary treatment in the trial is **Natriumklorid B. Braun 9 mg/ml innrennslislyf, lausn**, a **solution for injection/infusion** containing **sodium chloride**. This product is manufactured by B.Braun Melsungen AG and is authorized in Iceland. It is administered via **injection** with a maximum daily dose of 40 mmol/kg, and the treatment period is limited to 1 day. The active substance is of chemical origin, and the product is not formulated for pediatric use. This auxiliary treatment is used to support the primary and comparator treatments in the trial.

The efficacy of the clinical trial comparing intra-articular corticosteroid injection versus arthrocentesis for the management of clinical arthritis of the temporomandibular joint (TMJ) will be assessed using both primary and secondary endpoints. The primary endpoint is pain relief, which will be measured using a 100 mm Visual Analogue Scale (VAS) at baseline, and at 1, 3, and 6 months post-treatment. This scale is a validated tool for assessing pain intensity, providing a quantitative measure of the patient's pain experience over time.

Secondary endpoints include the measurement of maximal mouth opening in millimeters at the same time intervals: baseline, 1, 3, and 6 months after treatment. Additionally, psychosocial factors will be evaluated using a series of questionnaires, including the Patient Health Questionnaire (PHQ-9 and PHQ-15), Generalized Anxiety Disorder 7-item scale (GAD-7), and the Pain Catastrophizing Scale (PCS). During each visit, the Jaw Functional Limitation Scale (JFLS) and the Graded Chronic Pain Scale (GCPS) will also be assessed through questionnaires. Furthermore, the presence of degenerative bone changes will be examined by an oral radiologist and graded as either 0 (no bony changes) or 1 (bone changes in the TMJ).