Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2018-04-10, 12:30:21 | version 1.38.0
| case report Computer-assisted implant rehabilitation of tumour patients Ioannis Papadimitriou, Dr Petros Almagout, Dr Erich Theo Merholz & Dr Stefan Helka, Germany & Greece Implantology has become a fundamental, if not routine, component of oral rehabilitation and the most reliable procedure in the discipline’s attempt to re- alise restitutio ad integrum. In modern dentistry, im- plant-supported restorations are considered to be the usual and best care options. However, particularly in patients with malignancies of the oral cavity, there are fundamental changes to the anatomy of the oral cav- ity due to the extensive surgical procedures and adju- vant radiotherapy. In the post-irradiated jaw, a purely mucosa-supported prosthesis is not indicated ow- ing to xerostomia and the necrosis risk of irradiated bone. The only practical way to prevent load on the mucosa is the insertion of dental implants and the sub- sequent incorporation of an implant-supported fixed denture.1, 2 Traditionally, determining implant position, size, num- ber, direction and placement depended on the pre- operative diagnostic imaging, which was limited to 2-D radiographs and guiding templates. Three-dimensional imaging and navigational aids offer the treating implan- tologist enhanced certainty and additional options, es- pecially in high-risk cases, such as patients with extreme alveolar ridge atrophy or patients with malignancies of the oral cavity. With 3-D imaging, implant prosthetic dentistry has taken a major step forward. The dentist can plan the surgical procedure virtually in combination with 3-D planning programs.5–7 This has been made possible mainly by the steady improvement of specific implant planning programs, such as CTV (computer tomography visualisation) software. With navigated implantology, it is possible to pass through the alveolar crest, locate structures and as- sess the existing bone at all levels. On the basis of the available data obtained on computer, the length, incli- nation, diameter and ideal position of the implants can be determined.1–4 Prerequisite for navigated implantol- ogy is the use of appropriate imaging techniques, par- ticularly the 3-D radiographic method of cone beam computed tomography (CBCT; Table 1).6–8 This mod- ern 3-D diagnostic enables detailed surgical planning of implantation, taking into account prosthetic consid- erations. Navigated implantology offers several advan- tages:7–9 – precisely guides the osteotomy drills, through a secure, reproducible positioning of the template, directing the surgeon on the exact location and angulation to place the implant based on the virtual treatment plan; Effective dose in µSv Multiple doses of a dental panoramic tomogram Dose as % of annual natural radiation Dental panoramic tomogram GALILEOS default ILUMA default I-CAT Planmeca ProMax NewTom CT scan ~6 29 331 68 210 39 1 5 52 11 33 6 2,100 323 Table 1: Comparison of radiation exposure of various methods and systems. 0.2 1.0 11.0 2.3 7.0 1.3 70.0 Table 1 16 1 2018