Program including abstracts as pdf available here

OP 55
Title
EFFECTS OF MALPOSITIONING ON PANORAMIC RADIOGRAPHy –
HIGHLy PRECISE ANALySIS uSING AN IMPLANT MODEL
aBSTracTS OP 5
Authors
b. RIECKE 1 , D. SCHuLzE 2 , R. E. FRIEDRICH 1 , M. bLESSMANN 1 , C. LOOS 3 , M. HEILAND 1 ,
J. WIKNER 1
Affiliations
1 OCMF Surgery University Medical Center Hamburg Eppendorf, Hamburg, GERMANY, 2 Centre
of Oral and Maxillofacial Radiology, Freiburg i.B., GERMANY, 3 Institute for Media and Imaging
Technology, University of Applied Sciences¬, Cologne, GERMANY
Body
Objectives:
The panoramic radiography underlies well known intrinsic procedural disadvantages due to its
nature as a special kind of tomography. These are inconsistent magnification of the tomographic
image, poor definition, geometric distortion and spatial depositioning of objects situated
outside the focal trough. Even in exact position of the patient and individualized focal trough
these disadvantages immanently occur to a certain extent due to the different shapes of the
dental arches of maxilla and mandible and the individual variety of the angle between the
occlusal plane and the Frankfurt horizontal plane.
Methods: A special developed implant model was mounted on a highly precise goniometerrotation-table
and then moved horizontally, tilted and rotated in five degrees of freedom.
Digital panoramic radiographs were taken using a promax 3D device (planmeca, finland). To
determine the minimal error of image distortion in each malpositioning quality 1) the implant
model was rotated and tilted around the intersection point of the virtual straight line from the
center of the condyles with the contralateral canine positions within the occlusal plane thus
enabling constant reference planes and 2) all malpositioning qualities have been evaluated
separately. Semi-automated digital image analysis was performed with the image J software.
Results: Due to the method immanent conditions multiple aberrations occurred in the panoramic
image in separately evaluated malpositioning qualities. Even in marginal deposition up to
5 mm or 5° relevant errors in the images were detected.
Conclusion: This study demonstrates the quantitative effect of highly precise sterical malpositioning
on panoramic radiography and presents a suitable model for its evaluation. The results
are retraceable and reproducible and determine the minimal error related to the particular
malpositioning quality. Errors resulting out of combined malposition directions have to be
assumed as increased. The observed dimension of these effects additionally to the known
physicotechnical insufficiency of the panoramic radiography demonstrates its incapability in
precisely interpreting spatial relationships.
On the basis of the presented data the recommendation of three dimensional imaging for
spatial evaluation should be considered.
Keywords digital panoramic radiography, panoramic radiography
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