Integrating motion capture technology and intraoral ultrasonography for 3D anatomical analysis

The inherent two-dimensional (2D) nature of ultrasonography (US) limits its accuracy in visualizing complex intraoral structures. This proof-of-concept feasibility study introduces a novel approach integrating motion-capture technology and three-dimensional (3D) reconstruction to overcome these limitations and improve anatomical interpretation. Two healthy Korean volunteers underwent real-time 2D B-mode intraoral US (11.5 MHz) targeting the maxillary second molars in the occlusal plane. Magnetic resonance imaging (MRI) and 3D facial scans were performed with a 2.7-cm-wide mouth opening, and the images were superimposed. A motion-capture camera tracked the US probe to verify the 3D positioning of the US images. The integrated system enabled visualization of complex anatomical structures surrounding the coronoid process with greater spatial context. Comparative analysis between US images, 3D models, and MRI confirmed the feasibility of accurately locating intraoral anatomical features with high reproducibility. This feasibility study demonstrates the utility of motion capture and 3D imaging in enhancing intraoral US. Accurate spatial localization is essential due to the dynamic positioning of adjacent structures affecting the temporomandibular joint. The findings provide foundational data for standardizing future intraoral US methodologies and suggest directions for real-time anatomical analysis and procedural guidance, such as US-guided botulinum toxin injection into the temporalis tendon or preoperative implant site planning.