Currently, three-dimensional (3D) cephalometric analysis using cone beam computed tomography (CBCT) has become common during surgical orthodontic treatment. Treatment plans are established through 3D analysis, and post-surgical treatment results are analyzed and evaluated. The first thing that must be done for 3D analysis is to position the patient's head reproducibly every time CBCT is performed to detect consistent anatomical landmarks. Conventionally, a natural head position is recommended. However, if a patient has difficulty controlling voluntary muscle movements due to a systemic disease such as epilepsy, the success of treatment cannot be assured with traditional methods based on natural head position.

In this presentation, we would like to introduce the surgical orthodontic collaboration system between orthodontists and oral and maxillofacial surgeons for an unusual patient with epilepsy. To consistently maintain this patient's head posture, we developed a landmark-free reorientation methodology based on principal component analysis (PCA) for harmonious orientation of serially captured CBCTs. Furthermore, in our approach to orthognathic planning, we have leveraged advanced digital technologies to enhance precision and effectiveness. We can create comprehensive virtual treatment plans using digital simulation tools, allowing for detailed pre-surgical visualization and adjustment. Moreover, we would like to introduce an algorithm that can automatically detect curvilinear landmarks such as Orbitale and Porion to minimize human landmark detection errors. This enabled automatic reference planes without human manipulation and precise 3D analysis, enabling more reliable treatment. This digital integration facilitates better communication between the surgical and orthodontic teams, ensuring that the planned surgical outcomes align closely with the desired orthodontic results. By incorporating these digital methods, we enhance the accuracy and predictability of orthognathic surgeries, leading to improved patient outcomes.