Finite-Element Computer Modeling of Spatial Displacement of the Pterygoid Venous Plexus During Mandibular Movements

The safety of mandibular anesthesia is directly dependent on a precise understanding of the spatial relationships in the pterygomandibular space, particularly the risk of injury to the highly vascularized pterygoid venous plexus (PVP). In vivo studies of PVP displacement during mandibular movements face significant technical challenges. Objective: The study aims to study the spatial displacements of the pterygoid venous plexus during various physiological positions of the mandible using computer modeling with the finite-element method (FEM). Materials and Methods: A three-dimensional finite-element model was developed based on computed tomography data and the BodyParts3D anatomical atlas. The model included the bony structures of the skull, mandible, temporomandibular joint, masticatory muscles, and blood vessels. Simulations were performed for vertical displacements of the jaw at 15, 25, and 35 mm, as well as horizontal displacements of 5 mm to the left and right. Results: It was found that the magnitude of PVP displacement is proportional to the degree of mouth opening. The maximum total displacement (1.24 mm) was recorded at a 35 mm opening along the "posterior-medial-inferior" vector. Lateral excursions revealed asymmetry: displacement to the right caused plexus movement posteriorly, medially, and inferiorly (0.66 mm), while displacement to the left resulted in movement anteriorly, laterally, and superiorly (0.64 mm). Conclusions: This study demonstrates the significant mobility of the pterygoid venous plexus, which depends on the direction and amplitude of mandibular movements. The obtained data have important practical implications for planning regional anesthesia and minimizing the risk of iatrogenic complications. From a biomechanical perspective, maximum mouth opening produces the greatest displacement of the PVP, which may hypothetically reduce the risk of vascular puncture. Clinical studies are required to confirm this.