Subjective image quality assessment of cross sectional imaging methods for the symphyseal region of the mandible prior to dental implant placement.

OBJECTIVES: A three dimensional appreciation of the form of the anterior mandible is required to place dental implants safely in the region. This study compared the subjective image quality of four available methods of cross sectional imaging of the symphyseal region, the lateral cephalometric view, cone beam computed tomography (CBCT), spiral tomography and the transymphyseal X-ray view. METHODS: An experimental water phantom was developed to reproduce human soft tissue around the mandible. Images were taken of four mandibles by the four X-ray techniques. Three different CBCT machines were included. The source of each image was disguised by displaying all images in the same format on the same computer screen. A protocol was developed to process the images for viewing whilst preserving their image quality. A panel of observers of ten dentists viewed the images and rated their image quality by recording their agreement with six statements on a five point Likert scale. RESULTS: The results showed a statistically significant difference in image quality between imaging methods. There were clear differences in the ratings between the three cone beam computed tomography machines. Small volume, high resolution CBCT provided images with the highest scores for subjective image quality. CONCLUSIONS: Within the limitations of this study, significant differences in subjective image quality were found between imaging systems used for cross sectional imaging for the symphyseal region of the mandible prior to dental implant placement.