Читать книгу Bone and Soft Tissue Augmentation in Implantology - Группа авторов - Страница 53

The panoramic radiograph is an overview, giving general information on the dentition and bone volume and allowing the localization of anatomically sensitive structures such as the inferior alveolar nerve, sinus floor, and nose. Panoramic radiographs show an enlargement of 15% to 25% of the anatomical structures; this varies between the different company brands and also depends on the positioning of the patient during the scan. In the case of implant planning in the proximity of anatomically relevant structures, a reference ball is positioned per segment in order to obtain the most accurate metric analysis possible in the surgical field (Fig 2-14c). With the aid of tomography, rough information regarding the bone quality is provided. Additional devices also provide transversal layers of the planned operating area, first made possible by the Scanora device.⁵ However, since these layers have to be controlled individually, no data can be created for further processing in planning and surgical guide software. One of the latest developments is panoramic imaging using the multilayer technique. During a standard scan, about 4000 raw images are stored, which also allows for a repeated reconstruction to change the position of the skull or the size of the panoramic curve. Due to the multiple slices, the visualization of the bone structures is improved, which offers more information about the expected bone quality.

For planning implants in routine cases or in cases with moderate atrophy, the panoramic overview provides very good information about the positional relationships, so that usually no further radiologic diagnosis for implant positioning is necessary.