چکیده
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Background: The purpose of this study was to compare cone-beam computed tomography (CBCT) to
conventional panoramic and panoramic-like radiography with regard to the accuracy of angulation
measurements between the long axes of adjacent teeth using different head orientations.
Methods: This cross-sectional study used pretreatment records from 30 orthodontic patients who had
undergone concurrent (interval, <6 months) CBCT imaging in a 12-in field of view and conventional
panoramic radiography. Three panoramic-like images were constructed on each CBCT scan: 1) ideal head
position (0); 2) head rotated upward (þ10); and 3) head rotated downward (10). The upper and
lower right central and lateral incisors as well as the upper and lower right premolars were selected on
each image. The angles between adjacent teeth on frontal and lateral views on CBCT were measured and
compared to the corresponding angles on the panoramic views.
Results: Interdental angles on CBCT imaging were significantly greater compared with those on panoramic
(P 0.001) and panoramic-like (P 0.003) imaging in the upper and lower anterior areas. At þ10 on
panoramic-like imaging, the interdental angles between the upper central and lateral incisors tended to be
decreased significantly compared with those on CBCT. Other sites did not show significant variations.
Conclusions: In the present study, the anterior teeth showed more parallelism on panoramic imaging
(conventional or panoramic-like) compared with CBCT. In contrast, the posterior region showed no
differences between CBCT and radiography. Interdental angles in the anterior region of panoramic like
image are more close to CBCT measurements when head oriented ideally or slightly downward.
2014 World Federation of Orthodontists.
1. Introduction
The importance of establishing appropriate axial inclinations
with near-parallel roots has been frequently emphasized in the
orthodontic literature [1,2]. This parallelism is of prime importance
for o
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