title: Validation of quantitative digital subtraction radiography using the electronically guided alignment device/impression technique.
abstract: The electronically guided alignment device (EGAD) has been demonstrated to function well with a custom fabricated stent for taking radiographs for subtraction. The objective of this study is to demonstrate that this device functions well when used with an impression bite-block rather than a full arch acrylic stent. Nineteen subjects participated. Two vinyl siloxane impressions were made for each subject and a pair of x-rays was taken with each impression. The location for study was divided among 7 for the maxillary premolar-1st molar region, 6 for the mandibular premolar-1st molar region, and 6 for the incisor-canine region. To simulate bone change 3 bone chips (approximately 1, 7, and 10 mg) were positioned in the mucobuccal fold when one of each pair of x-rays was taken. Pairs of radiographs were subtracted and the bone change (chips) isolated by thresholding to determine their area. An aluminum ramp was used to determine volume. A strong linear relationship between actual chip weight and equivalent aluminum volume (r2 = 0.64, P < 0.001) was obtained for all regions of the mouth when considered together. The strongest relationship of the 3 regions was for mandibular premolar-1st molar sites, r2 = 0.78. These data indicate that the EGAD/impression technique is suitable for taking radiographs in all areas of the mouth for quantitative digital subtraction.
authors.affiliation: Department of Oral Biology, School of Dental Medicine, State University of New York, Buffalo, USA.
authors.forename: E
authors.initials: E
authors.lastname: Hausmann
authors.forename: K
authors.initials: K
authors.lastname: Allen
authors.forename: J
authors.initials: J
authors.lastname: Loza
authors.forename: W
authors.initials: W
authors.lastname: Buchanan
authors.forename: P F
authors.initials: PF
authors.lastname: Cavanaugh
mesh_terms: D000328:Adult; D003761:Dental Impression Technique / Q000295:instrumentation*; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D011145:Polyvinyls; D011856:Radiographic Image Enhancement / Q000295:instrumentation; D011861:Radiography, Dental / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012833:Siloxanes; D013382:Subtraction Technique / Q000295:instrumentation*
chemical_list: D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane