Ultrasound-Guided Botulinum Toxin A Injection for TMJ Disc Displacement With Reduction

This study investigated the therapeutic potential of ultrasonography-guided botulinum toxin type A (BTX-A) injection into the lateral pterygoid muscle in patients diagnosed with temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDwR). The intervention was performed under local anesthesia with patient monitoring. High-frequency ultrasonography was utilized to accurately identify the lateral pterygoid muscle and guide the injection to minimize risks to adjacent anatomical structures. The study followed patients over a 6-month period to assess changes in TMJ-related pain, functional parameters, and disc position. Pain intensity was measured using the Numerical Pain Rating Scale (NPRS), joint sounds were assessed clinically and with a stethoscope, disc position was evaluated via MRI, and mandibular movements were assessed by measuring lateral excursion and maximum interincisal opening. Patient-reported outcomes were also evaluated using the Fonseca's questionnaire. The findings demonstrated a significant reduction in TMJ pain and joint noises, as well as improved mandibular function and disc alignment during the follow-up period. No major complications were observed, supporting the safety and efficacy of ultrasound-guided BTX-A injections in managing ADDwR. This research provides clinical evidence for a minimally invasive and precise technique to manage TMJ internal derangements and reduce the impact of hyperactive lateral pterygoid muscle activity.