The masticator space in 3 dimensions: combining radiographic imaging, peer-reviewed literature, and medical illustration to create an anatomically-accurate digital model

Abstract

Development of an anatomically accurate, digital, 3-dimensional (3D) model of the masticator space, including the muscles of mastication and temporomandibular joint, by combining data from radiographic imaging and published literature, and augmenting this with medical illustration. The present study involved the manual segmentation of the muscles of mastication, namely the masseter, temporalis, medial pterygoid, and lateral pterygoid muscles, as well as the buccinator muscle from a head and neck CT angiogram of a healthy 29-year-old female. The skull base, supporting structures, and adjacent major arteries were also segmented from the same study. The segmentation was then refined based on a compilation of data from published anatomical studies, which were utilized to provide additional anatomical detail for each muscle. Published studies were also used to incorporate structures unable to be segmented by this imaging technique, specifically major cranial nerves and the temporomandibular joint. The resulting anatomical details were subsequently incorporated into a 3D model by a professional medical illustrator. A total of 5 left-sided muscles were segmented from CT angiography data and were incorporated with segmentations of the skull base and mandible. Meshes were further refined in digital 3D space based on data from peer-reviewed anatomical studies. The left temporomandibular joint, sphenomandibular ligament, and stylomandibular ligament, as well as the left trigeminal nerve and maxillary artery and its branches were incorporated into the model to highlight important surgical anatomical relationships. Finally, the model was uploaded to a publicly available 3D repository, available at https://shorturl.at/hnrVZ. This 3D study serves to demonstrate, in a layered fashion, the complex anatomy of the muscles of mastication, including their relationship with important cranial base and neurovascular structures relevant to common surgical procedures and approaches to the infratemporal fossa. Moreover, it serves as an adjunct to the other studies published in this issue.