Assessment of the Effectiveness of Intra-articular Injectable Platelet-rich Fibrin (iPRF) Injections in the Management of Mild and Moderate Degeneration of the Temporomandibular Joints

Background: The term temporomandibular disorders is used to describe a wide spectrum of functional modifications and pathological conditions involving the temporomandibular joints, masticatory muscles and other surrounding structures. Temporomandibular disorders are the second most common cause of pain symptoms in the craniofacial area. It is estimated that they may affect up to 56% of the adult Polish population. One of the most common forms of temporomandibular disorders are intra-articular abnormalities. They can lead to degeneration within the articular surfaces and articular disc of the joints. The treatment of degeneration of the temporomandibular joints is a great therapeutic challenge. There are scientific reports suggesting that one of the effective methods may be intra-articular injections. Injectable platelet-rich fibrin (iPRF) is an autologous material obtained from human blood, which contains a high concentration of inactivated platelets, white blood cells and mesenchymal stem cells. After injection into the tissues, it initiates natural repair processes. Despite the fairly wide possibilities of application, this method has not yet been tested in terms of its use in the treatment of degeneration of the temporomandibular joints.

Aim: The aim of the study is to evaluate the effectiveness of intra-articular platelet-rich fibrin injections in the management of moderate and mild cases of degeneration of the temporomandibular joints.

Material and methods: A randomized, two-arm controlled trial will involve 42 adult patients diagnosed with mild or moderate degeneration of the temporomandibular joints on the basis of clinical examination and magnetic resonance imaging or computed tomography. Criteria for exclusion from the study will include: severe hematologic and/or neurological disorder; rheumatoid arthritis; septic arthritis; polymyalgia rheumatica; gout; Paget's disease; osteonecrosis; connective tissue disease; malignant disease; vasculitis; any previous temporomandibular joint invasive treatment; any current temporomandibular joint conservative or invasive treatment; patients who had used oral, parenteral or intra-articular corticosteroids in the 3 months prior to the first injection; previous or current radiotherapy of head and neck; pregnancy or lactation; presence of severe mental disorders; drug and/or alcohol addiction; presence of local contraindications for injection therapy; patients with needle phobia; presence of hypersensitivity to substances to be used in the study.

Qualified study participants will be randomly assigned to two groups. The studied group will receive two injections of iPRF with an interval of 30 days, while the control group will receive injections of platelet-rich plasma (PRP) during this time. The use of PRP has been already described in the scientific literature as being effective in the treatment of joint degeneration. Each subject will be tested on the day of the first injection (D0), on the day of the second injection (D30), and then 60 (D60) and 12 (D120) days after the first injection using the following methods:

1. Magnetic resonance imaging of the temporomandibular joints (D0)
2. Examination with the Doppler Hi-dop (D0, D30, D60, D120)
3. Examination of the mandibular mobility ranges with a professional ruler (D0, D30, D60, D120)
4. Clinical examination according to diagnostic criteria for temporomandibular disorders - DC / TMD International Examination Form (D0, D120)
5. Surveys: Short Form 36 (SF-36), General Oral Health Assessment Index (GOHAI (HRQoL)) (D0, D60, D120), Jaw Functional Limitation Scale-20 (D0, D30, D60, D120), TMD Pain Screener (D0, D30, D60, D120) Pain Numerical Rating Scale (D0, D30, D60, D120), Graded Chronic Pain Scale (DO, D30, D60, D120).