Botulinum Toxin Versus Platelet Rich Fibrin for TMJ Internal Derangement

Temporomandibular joint (TMJ) internal derangement represents a common cause of temporomandibular disorders (TMDs) and is frequently associated with pain and functional limitations. Patients affected by TMJ internal derangement commonly present with pain during mastication, difficulty or pain during mouth opening, joint sounds such as clicking or crepitation, and preauricular pain. Due to the multifactorial nature of this condition, numerous treatment modalities have been investigated to achieve effective symptom relief and functional improvement. The aim of this clinical study was to evaluate and compare the effectiveness of botulinum toxin type A (BOTOX) injection into the lateral pterygoid muscle versus intracapsular injection of injectable platelet-rich fibrin (I-PRF) for the management of TMJ internal derangement. This randomized clinical study was conducted on a total of 20 patients diagnosed with TMJ internal derangement. The participants were randomly and equally allocated into two groups using an online randomization tool (www.randomizer.org). Group I consisted of 10 patients who received intracapsular injections of injectable platelet-rich fibrin (I-PRF) into the superior joint space of the temporomandibular joint. Group II consisted of 10 patients who received botulinum toxin type A injections into the lateral pterygoid muscle. Patients in both groups were evaluated using both subjective and objective parameters at baseline and during follow-up periods at one month, three months, and six months following injection. Clinical evaluation included assessment of pain, maximum mouth opening, and mandibular movements in all directions to determine improvement in mouth mobility. Tenderness was assessed by palpation of the masticatory muscles, including the temporalis, masseter, and lateral pterygoid muscles, as well as palpation of the temporomandibular joint through the external auditory canal. Radiographic evaluation was performed using magnetic resonance imaging (MRI) to assess intra-articular changes of the temporomandibular joint following treatment. MRI findings were used to evaluate joint structure, disc position, and overall intra-articular condition after the intervention. The outcomes of this study were analyzed to determine which treatment modality provided superior clinical and radiographic improvement in patients with TMJ internal derangement.