Photon-Counting CT in Oral and Maxillofacial Imaging: Clinical Applications, Dose Efficiency, and Future Perspectives

Photon-counting computed tomography (PCCT) is an emerging imaging technology that combines ultra-high spatial resolution, improved dose efficiency, reduced electronic noise, and intrinsic spectral imaging. These characteristics are particularly relevant to oral and maxillofacial radiology, where accurate depiction of small osseous and dental structures is often required in the presence of metallic restorations or implants. This review summarizes the technical principles of PCCT and examines its current and potential clinical applications across dental and maxillofacial imaging. Available evidence indicates that PCCT can improve visualization of fine root canal anatomy, periodontal and trabecular bone structures, peri-implant interfaces, subtle maxillofacial fractures, and complex sinonasal anatomy. Its spectral capabilities, including virtual monoenergetic imaging and material decomposition, may substantially reduce metal-related artifacts and improve tissue characterization. Early studies also suggest that PCCT can provide high diagnostic image quality at reduced radiation dose, with potential advantages in pediatric imaging and in patients requiring repeated examinations. Beyond morphology, PCCT may support quantitative applications such as bone mineral density assessment, iodine mapping, treatment planning, and the development of imaging biomarkers and artificial intelligence-based analysis. Despite these promising findings, cone-beam CT remains the preferred modality for many routine dental indications because of its accessibility, lower cost, and established clinical workflow. Current evidence for PCCT in oral and maxillofacial radiology is still limited and is largely derived from technical, experimental, and early clinical studies. Further prospective comparisons with cone-beam CT and conventional CT are needed to define task-specific diagnostic benefits, optimized protocols, radiation-dose advantages, and cost-effectiveness. PCCT is therefore best regarded as a promising complementary modality with particular value in diagnostically challenging cases that require very high spatial resolution, spectral information, or effective metal-artifact reduction. Nevertheless, most oral and maxillofacial evidence remains exploratory; improved image-quality metrics should not be equated with superior patient-level diagnostic accuracy. Direct comparisons with optimized CBCT yield heterogeneous, protocol-dependent dose and diagnostic findings. No standardized indication-specific PCCT acquisition framework currently exists for routine oral and maxillofacial imaging. Clinical implementation should therefore be conditional on demonstrable diagnostic benefit at a justified radiation dose and acceptable resource cost.