Mandibular deviation (MD) is a common reconstruction sequela after segmental mandibulectomy. Although proper postoperative rehabilitation is critical for MD management and minimization, the available information is limited. This report describes postoperative. rehabilitation with an occlusal splint fabricated using CAD/CAM (CAD/CAM-OS) and the results of a 3D occlusal analysis using an intraoral scanner (IOS) after hemimandibulectomy and plate reconstruction. Despite the short follow-up, adherence to postoperative rehabilitation with CAD/CAM-OS for MD correction, even during radiotherapy, was demonstrated by the digital workflow and analysis results.