Stepwise radiological examination is a key element in dentistry and dentoalveolar surgery. The basic examination is the panoramic X-ray which provides essential information by giving an overview of the stomatognathic system. Therefore, the panoramic X-ray is mandatory to answer many diagnostic questions. With accurate interpretation and exact reading, the panoramic X-ray also represents a relevant document for forensic purposes. In cases showing discrepancies between clinical and radiological findings or in situations with insufficient information, standard panoramic X-ray is followed by further radiologic appraisal, such as cone beam CT. This diagnostic tool provides steric presentation of the pathologic finding and thus has significant impact for therapeutic and forensic aspects.
The aim of this thesis was to compare the diagnostic value of the panoramic X-ray with cone beam CT and to draw conclusions concerning their indications for specific clinical questions.
For this purpose, the complete clinical documentation of patients at the Maxillofacial unit at the Klinikum rechts der Isar, Munich, was evaluated together with their panoramic X-rays, and the indications for further diagnostics using cone beam CT were reviewed on the basis of the patient’s records. Documents of 302 patients were assessed and classified into 6 groups with comparable clinical findings. The indications to perform a cone beam CT were evaluated according to the individual data of each patient. Following a standardised and systematic sequence, panoramic X-rays and cone beam CT’s of each patient were analysed. All individual findings of both radiographic modalities were exactly described and compared. The patient charts were checked for further therapeutic measures, and decisions concerning the surgical procedures were identified, which were directly dependent from the results of the radiological procedures. Thus, the diagnostic value of three dimensional imaging and its influence toward surgical planning could be assessed.
Statistical evaluation was carried out by using SPSS (Statistical Package for Social Sciences) software for Windows (Version 20, SPSS Inc. Chicago, Illinois, USA) and GraphPad Prism, version 6 (GraphPad Prism Software® San Diego, USA). Simple calculations and further processing of data was performed by using Microsoft Office Excel 2011 (Microsoft Corporation, Redmond, USA).
In summary it could be stated, that cone beam CT represents an ideal amendment to conventional panoramic X-ray for most indications due to three dimensional imaging of the specific pathology. Reasonable indications to use the cone beam CT are the evaluation of spatial relationships and the three dimensional analysis of hard tissues. Moreover, for certain indications, cone beam CT alone can be sufficient to answer specific clinical questions, such as mandibular neck fractures or diseases of the paranasal sinuses, which can be displayed without disturbing overlapping structures. For the examination of processes in these anatomical areas, three dimensional imaging facilitates diagnosis and can replace conventional panoramic X-ray.
In contrast to computed tomography, which displays soft and hard tissues at the same time, the limitation of the cone beam CT-technology is the insufficient depiction of the soft tissues. Therefore, the cartilage of the temporomandibular joint and other pathologies of the soft tissues cannot be reliably evaluated when using this technique. Further limitations of this radiologic modality are movement artefacts which make interpretation and evaluation of the complete data impossible. Furthermore, diagnostics around enosseous dental implants is made impossible due to massive metal artefacts. No indications could be found to use cone beam CT to prepare for wisdom teeth removal in the upper jaw.
With elimination of the NIWID component and careful consideration of the ALARA principle, a meaningful evolution of diagnostic measures can be expected in the field of dentoalveolar surgery .
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Stepwise radiological examination is a key element in dentistry and dentoalveolar surgery. The basic examination is the panoramic X-ray which provides essential information by giving an overview of the stomatognathic system. Therefore, the panoramic X-ray is mandatory to answer many diagnostic questions. With accurate interpretation and exact reading, the panoramic X-ray also represents a relevant document for forensic purposes. In cases showing discrepancies between clinical and radiological f...
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