Medizinische Universität Graz - Research portal
Selected Publication:
Reichmann, J.
Measurement of the mandibular canal with different radiographic techniques
[ Diplomarbeit ] Medical University of Graz; 2011. pp. 64
[OPEN ACCESS]
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- Authors Med Uni Graz:
- Advisor:
- Jakse Norbert
- Pertl Christof
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- Abstract:
- Abstract Aim of this study was to evaluate the exactness of different radiographic technologies to examine the position of the mandibular canal. Implant surgery in the posterior mandible requires the knowledge of the mandibular canal position. Ten preserved lower jaws were used to compare the exactness of conventional panoramic radiography, panoramic radiography with a reference ball, CT and cone beam computed tomography. In order to guarantee reproducible measuring between different radiographs, the jaws were marked with two gutta-percha points at each test point. Afterwards radiological images of the marked jaws were taken with the different techniques and consequently evaluated. The mandibles were then sawn at the planned areas and the exact anatomical distances to the mandibular canal were determined. Compared to the sawn mandibles, in digital panoramic radiography an average difference of +2.3mm (range from ¿0.2 mm to +5.7 mm) was found. In panoramic radiography with a ball reference stencil an average of +0.2 mm (range from ¿1.6 mm to +3 mm) compared to the location of the mandibular canal in cadavers was measured. Furthermore a magnification factor by 1.17 was calculated about the measurement of the reference balls of the Orthophos XG plus made by the company Sirona. CT measurement showed a difference of ¿0.2 mm within a range from ¿1.5mm to +1.3mm, there were some outliers to ¿2.7 mm and +2.3 mm. The DVT had similar results with a median of ¿0.3 mm (range from ¿1.5 mm to +0.8 mm) and only two outliers to ¿1.9 mm and +1.0 mm. The result of this study confirmed, that for implantation in the posterior mandible a conventional panoramic X-ray examination is not sufficient for an exact vertical linear measurement to the nervous canal. Using a reference ball, a clearly separable mandibular canal and a rise of the safe distance to the canal from 1.5 mm to 2 mm, the ball X-ray examination can be recommended for standard implantations. The most exact results were achieved with the CT and the DVT techniques. The cone beam computed tomography showed less measuring mistakes.