Efficacy of Injectable PRF in Management of TMJ Internal Derangement

Temporomandibular disorders (TMD) are a significant public health problem affecting approximately 5-12% of the overall population and are considered the most common cause of chronic pain of non-dental origin in the orofacial region(Hegab et al2021) The internal derangements (IDs) are considered as the most common non- inflammatory disorders of the TMJ, since they affect about 10% of the population worldwide and represent approximately 41.1% of all temporomandibular disorders. The term "internal derangement" refers to abnormal pathways during the functional movement of the TMJ that mostly involves the articular disc function, how ever, IDs could be observed even in asymptomatic individuals (Ghonim et al 2022) joint osteoarthritis (TMJ OA) is a common disorder among the population, is more prevalent in females than in males, and increases in prevalence with age.1 Me chanical and biological events including overloading, bruxism, and unilateral chewing, as well as genetics factor ( Co¨mert Kilic et al2016 ) The pathogenesis of this temporomandibular joint dysfunction has pointed to biochemical factors ,separate from the disc displacement theory .for example

,inflammatory reactions that occur in TMJ are essential for the development and progression of the disease ,including high levels o inflammatory mediators in the synovial fluid ,such as interleukin 1 beta ,tumor necrosis factor alpha and others

.furthermore, the disintegration of the important component of the synovial fluid, the hyaluronic acid (HA) ,leads to a decrease in viscosity of the synovial fluid and degeneration of the joint proteoglycans.(Mahmoud Hassan Toamah et al 2019)

Temporomandibular joint disorders include disk displacements, with or without reduction, that may be associated with inflammatory changes, such as capsulitis and retrodiscitis, or with degenerative changes, such as temporomandibular joint (TMJ) osteoarthritis and osteoarthrosis.3 Common symptoms include pain, which is aggravated by the mandibular movement, joints sounds (clicking or crepitus), a decrease in masticatory efficiency, and functional limitation in the mandibular movement(Harba, A. and Harfoush, M. 2021) . Injection of intra-articular medicaments is an accepted therapy for temporomandibular joint disorders (TMDs)( Jacob, S.M. et al. (2021) Arthrocentesis is minimally invasive technique , less expensive than surgical procedures and simple with low morbidity used for flushing the TMJ that is done by access to the upper joint compartment ( H.A.M.Marzook et al 2020). lavage helps remove the inflammatory mediators and cells . It is done when conservative treatment fails to treat the TMJ disorders using patient education physical therapy, or splints . at first it was done by saline or Ringers solution to just flush and lavage the joint but then corticosteroids were used to benefit from their anti inflammatory action . Hyaluronic acid is also used in arthrocentesis due to its lubricant effect, Platelet-rich plasma (PRP) is a biological therapy that comprises an autologous concentrate of platelets acquired by blood centrifugation [11]. This concentrate has shown potential benefits due to the abundance of growth factors within it(Abaddi et al 2022 )it has analgesic ,anti inflammatory and antibiotic effect ,helps restore intraarticular acidic acid and stimulates cartilage cells to produce Glycosaminoglycans, regulates the balance angiogenesis within the joint ,induces cell proliferation and cartilage production through cartilage cells ,increases the production of hyaluronic acid though synovial cells ,achieves high concentration of growth factors especially TGF-B[Mustafa Manafikhi et al 2022] but there is still a concern regarding the use of anticoagulants in preparation of PRP

Several studies were done to compare between HAand PRP in management of Temporomandibular joint disorders . Four of the studies found PRP injections to be superior in terms of improvements in mandibular range of motion and pain intensity up to 12 months after treatment, while the remaining two studies found similar results for the different treatments (Bousnaki M. et al 2018)

Two groups were included in the study ; the control group underwent arthrocentesis then injection of Hyaluronic acid gel whereas the study group underwent arthrocentesis then administration of injectable PRF

1-these patients were clinically examined and radiographically using MRI

II-Operative stage : this study was conducted under local anesthesia (LA).

1. after disinfection of the operative field and injection of local anesthesia, a reference line was drawn from the outer canthus of the eye to the tragus of the ear [cantho- tragal line] .
2. Double injection technique was used , the first point was marked along the the cantho -tragal line [Holmlund -Hellsing line] 2mm below the line and 10 mm in front of the tragus. The second point wasmarked 10 mm below the line and 20 mm from the tragus of the ear .

3. control goup was managed by injection of Hyaluronic acid [HA] after lavage of the upper compartment space using saline solution

   1. the first needle [20 gauge] was inserted in to the first marked ,point 2 mm below the cantho-tragal line and 10 mm from the tragus of the ear .
   2. the patient was instructed to open protrusively ,20ml of ringer's solution was injected into the upper joint space then 100mm of ringer's solution was injected that flow back out of the upper joint space through the second needle[20 gauge ] that was inserted 20 mm from the tragus of the ear and 10 mm below the cantho-tragal line.
   3. then 2ml of HA was injected through the first needle while the second needle was removed. Throughout the whole procedure, the patient was instructed to open and close the mandible to facilitate the flow of the solution inside the joint .
4. the study group ;arthrocentesis was done with the same steps as in the first group . the injectable platelet rich fibrin I- PRF was injected into the upper joint space. Injectable PRF was prepared immediately before arthrocentesis from centrifuging of blood taking from the ulnar vein in a tube without anticoagulants at 700 rpm for 3 minutes , after centrifuging it was separated from the blood hemocytes as I-PRF was collected on the top of the tube while the blood hemocytes being precipitated in the bottom of the tube , 2ml of I-PRF was collected then injected directly into the joint after arthrocentesis with ringers solution through the first needle .the mandible was manipulated in opening , closing and lateral movements to free the adhesion of the disc.

III-Post operative stage :

the patients in both groups were instructed to have soft diet, heat fomentation over the TMJ area and keep moving the mandible.

Analgesics and antibiotics were prescribed to avoid un necessary complications of infection.