Temporomandibular joint (TMJ) internal derangement is a common cause of temporomandibular disorders and is often associated with pain, restricted mandibular movement, joint sounds, and functional limitations during mastication and mouth opening. Various treatment modalities have been proposed to manage these symptoms, aiming to reduce pain and improve joint function. This randomized clinical study was conducted to 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) in the management of TMJ internal derangement. A total of 20 patients diagnosed with TMJ internal derangement were randomly allocated into two equal groups. Group I received intracapsular I-PRF injections into the superior joint space of the temporomandibular joint, while group II received botulinum toxin injections into the lateral pterygoid muscle. Clinical evaluation was performed using subjective and objective parameters at one, three, and six months following treatment. Outcomes included assessment of pain, maximum mouth opening, mandibular movements, joint tenderness, and muscle tenderness upon palpation. Radiographic evaluation was conducted using magnetic resonance imaging (MRI) to assess intra-articular changes of the temporomandibular joint following the interventions. The study aimed to determine which treatment modality provided superior clinical and radiographic outcomes for the management of 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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
20
Participants in this arm underwent arthrocentesis of the temporomandibular joint, followed by injection of 1 mL of intra-articular injectable platelet-rich fibrin (I-PRF) into the superior joint space.
Participants in this arm received an ultrasound-guided injection of 7 mL containing 35 units of botulinum toxin type A (BOTOX) into the lateral pterygoid muscle.
Suez Canal University, Faculty of Dentistry
Ismailia, Egypt
Pain Score (Visual Analogue Scale, VAS)
Pain associated with temporomandibular joint internal derangement was assessed using a 10-point visual analogue scale (VAS), where 0 indicates no pain and 10 indicates the worst pain. Pain was measured at baseline (pre-injection) and at follow-up visits. Comparisons were made within each group over time and between the I-PRF and BOTOX groups to determine the relative effectiveness of each treatment in reducing TMJ pain.
Time frame: 1 month, 3 months, and 6 months post-injection
Joint Sounds (Clicking) Assessment
The presence or absence of TMJ clicking was assessed by bimanual palpation during mouth opening and closing. Changes over time were recorded within groups and between the I-PRF and BOTOX groups.
Time frame: 1 month, 3 months, and 6 months post-injection
MRI Assessment of Disc Position
MRI was performed to evaluate the position and structure of the TMJ articular disc. Disc positions were categorized as Superior (Normal), Reducing Disc Displacement (RDD), or Non-Reducing Disc Displacement (NRDD). Changes were compared within each group over time and between groups.
Time frame: Baseline, 1 month, 3 months, and 6 months post-injection
Maximal Mouth Opening (MMO)
MMO was measured from the incisal edge of the upper central incisors to the incisal edge of the lower central incisors using a digital caliper. Measurements were taken at baseline and follow-up visits. Changes were compared within and between the I-PRF and BOTOX groups to evaluate improvement in mouth opening.
Time frame: 1 month, 3 months, and 6 months post-injection
Lateral Mandibular Movements (Right and Left)
Right and left lateral mandibular movements were measured from the maxillary midline using a millimeter ruler or caliper. Changes in lateral movement were evaluated within each group over time and between groups.
Time frame: 1 month, 3 months, and 6 months post-injection
Protrusive Mandibular Movement (PM)
Protrusive mandibular movement was measured from the midpoint of the maxillary central incisors to the midpoint of the mandibular central incisors using a millimeter ruler or caliper. Progression was assessed within each group and between the I-PRF and BOTOX groups.
Time frame: 1 month, 3 months, and 6 months post-injection
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