D Kohavi1, J Bar-Ziv, Y Marmary. 1. Department of Prosthodontics, Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel.
Abstract
OBJECTIVE: To assess the effect of angular deviation on the measured height of the mandible in reformatted cross-sectional CT scans. METHODS: Reformatted cross-sectional CT scans were obtained from three dried mandibles, at three angulations, in a special holding and positioning device for perpendicular measurements. The radiographic lengths of 321 measurements were compared with the actual bone length. RESULTS: The mean difference between actual bone length and image length, with transaxial planes parallel to the lower border, was 0% (s.d. 3.6). Deviations of 10 degrees and 20 degrees from the lower border of the mandible resulted in a mean error of 1% (s.d. 4.5) and 2.8% (s.d. 8.0) respectively. When the angulation between the deviated transaxial plane and the lower border was greater than 10 degrees, the maximum error was about +/- 30%. CONCLUSION: The use of different transaxial planes along the mandible may result, in a small proportion of cases, in discrepancies in height when measured from the cross-sectional images obtained. This may lead to incorrect interpretation of the depth of bone available for implants.
OBJECTIVE: To assess the effect of angular deviation on the measured height of the mandible in reformatted cross-sectional CT scans. METHODS: Reformatted cross-sectional CT scans were obtained from three dried mandibles, at three angulations, in a special holding and positioning device for perpendicular measurements. The radiographic lengths of 321 measurements were compared with the actual bone length. RESULTS: The mean difference between actual bone length and image length, with transaxial planes parallel to the lower border, was 0% (s.d. 3.6). Deviations of 10 degrees and 20 degrees from the lower border of the mandible resulted in a mean error of 1% (s.d. 4.5) and 2.8% (s.d. 8.0) respectively. When the angulation between the deviated transaxial plane and the lower border was greater than 10 degrees, the maximum error was about +/- 30%. CONCLUSION: The use of different transaxial planes along the mandible may result, in a small proportion of cases, in discrepancies in height when measured from the cross-sectional images obtained. This may lead to incorrect interpretation of the depth of bone available for implants.
Authors: Valentina Pompa; Sabrina Galasso; Michele Cassetta; Giorgio Pompa; Francesca De Angelis; Stefano Di Carlo Journal: Ann Stomatol (Roma) Date: 2011-02-13
Authors: George K Koch; Adam Hamilton; Kelly Wang; Laura Herschdorfer; Kyu Ha Lee; German O Gallucci; Bernard Friedland Journal: Dentomaxillofac Radiol Date: 2018-11-08 Impact factor: 2.419