2002 – VOLUME 31 – Issue 1

An experiment is conducted comparing the length of 162 intraoral implants with their measures on panoramic x-rays. These 162 measurements cover the diversity of the clinical reality and use an orthopantomograph OP10 (Siemens) and a competent radiologic technician. For each measurement, criteria such as arch, area, blur of the image are recorded. The analysis of the results shows that the average magnification is of 27,8 % (d=1,2). In practice, the manufacturer recommands to withdraw 25 % from the lengths measured on panoramic x-rays. By correcting this magnifying factor, the measurements appear to be overestimated by only slightly more than 0.5 millimeter. Thus, in the conditions of the experimentation, vertical measurements on panoramic x-rays appear to be reliable. This research also leads to other conclusions. Discrepancies between shape of the usefull thickness of panoramic x-rays and shape of the osseous crest are rare and results in minimal dimensional variations. Variation of the magnification depending on areas does exist but it is also of negligeable clinical incidence. The magnification is greater at the maxilla than at the mandibule, likely because of the location of the residual osseous crest more palatally located. The facial-palatal inclination of the osseous crest is of little influence on the magnification. The images appearing blur do not present magnified dimensional variations, although accurate measures are more difficult