Cephalometric radiographs are essential diagnostic tools for orthodontists, alongside dental models, panoramic radiographs, and facial and intraoral photographs. Since Dr. Broadbent developed the cephalometric radiography technique in 1931 and Dr. Downs introduced cephalometric analysis in 1948, various analytical methods have been proposed and continue to be crucial for evaluating pre- and post-orthodontic treatment and growth. However, there has been little mention of the conditions for capturing cephalometric radiographs since the concept of Natural Head Posture. For decades, the instructions have simply stated to fix the patient's head with "bilateral ear rods and a Nasion relator while gazing at a frontal mirror," without detailed guidelines or standards on head positioning.

Therefore, I propose the "Centric Head Posture" and emphasize the need for laser projection lines to achieve this posture accurately. Additionally, having practiced as an orthodontist for 20 years and using four different cephalometric radiographic devices, I have encountered challenges in superimposing radiographs taken under different conditions with each equipment change. Based on this experience, I have developed the "Ceph Verification Plate," a device designed to calculate magnification differences before and after equipment replacement. This presentation will introduce this tool and highlight the necessity of regular validation to monitor for radiographic distortions.