Needling Approaches to the Lateral Pterygoid Muscle: A Systematic Review of Cadaveric Studies

Background: Needling of the lateral pterygoid muscle (LPM) plays an important role in the management of temporomandibular disorders (TMD), particularly myofascial pain and disc displacements. Due to the deep anatomical location and close proximity to critical neurovascular structures, accurate needle placement is challenging and associated with potential risks. Cadaveric studies offer a controlled and reproducible environment for evaluating and refining needling techniques. Objectives: To systematically review cadaveric studies describing needling approaches to the LPM, with emphasis on injection techniques, needle characteristics, and guidance methods. Methods: The review was conducted in accordance with PRISMA guidelines. Searches of PubMed, Embase, Scopus, and the ACM Digital Library were performed to identify cadaveric interventional studies published within the last 20 years. Two independent reviewers conducted study selection with use of Rayyan app according to PICOS criteria. Extracted variables included: author and year, number of specimens, needle guidance method, anatomical injection landmarks, injection approach, needle specifications, and head positioning. Results: Out of 245 identified records, six studies met the inclusion criteria, encompassing a total of 44 cadaveric specimens. The majority of injections (84%) were performed via an extraoral approach, with one study utilizing an intraoral route. Needle lengths ranged from 50 to 75 mm, with gauges between 0.22 and 0.32 mm. Most studies relied on anatomical landmarks for guidance, while selected investigations employed computed tomography–based stereolithographic guides or ultrasound navigation to enhance accuracy. Electromyographic guidance, although clinically valuable, was not applicable in cadaveric models due to the absence of muscle activity. Conclusions: Extraoral approaches dominate cadaveric LPM research due to superior accessibility and operator control. Image-guided techniques improve accuracy but may be limited clinically by cost and technical demands. In contrast, EMG-guided intraoral injections offer a promising clinical solution, combining real-time placement confirmation with a favorable balance of precision, safety, and feasibility.