Temporal fossa radio- and sonoanatomy revisited: a multimodal approach to standardizing temporalis muscle thickness measurement.

Temporalis muscle thickness (TMT) has gained increasing importance as a parameter for predicting sarcopenia, dysphagia, and functional outcomes, particularly in cranial pathologies such as stroke. However, the complex anatomy of the temporal fossa presents a significant challenge for the reliable assessment of TMT. This review aims to overcome this difficulty by providing a comprehensive analysis of the sonoanatomy and radiologic structure of the temporal fossa. Detailed anatomical relationship, including fascial planes, fat pads, and bony structures are presented with high-resolution images and videos. In addition to this thorough anatomical evaluation, the study introduces a novel, standardized TMT measurement technique designed to be applicable across CT, MRI, and ultrasound modalities. This technique aims to enhance the comparability of measurements and to support the use of TMT as a more effective biomarker in the evaluation and follow-up of sarcopenia, dysphagia, and other orofacial conditions.