title: Evaluation of a simple modified radiographic alignment system for routine use.
abstract: Radiographic frames used for longitudinal studies may be in part unreadable for measuring crestal bone change. Sites may not be present on the film, or the measurement reliability may be compromised because of dissimilar geometry. Several techniques used to address this problem are expensive, time-consuming, and required great skill. For the present study a commercially-available alignment system was simply modified by addition of a reference pin in the bite block, facilitating the repositioning of the film holder for a second exposure. This study determined the ability of the modified instrument to: 1) improve the geometrical correspondence between serial radiographs; and 2) reduce the frequency of missed sites in the film. Two pairs of x-rays were taken for each of 40 subjects, 1 pair with the standard alignment instrument of an assigned site and 1 pair with the modified instrument of the contralateral site. Measurements of alveolar bone height were performed using the "side by side" technique. The modified instrument yielded significantly smaller measurement differences and a significantly better geometrical correspondence than the conventional system (P < 0.05). Also, the modified instrument yielded significantly greater (P < 0.01) readable sites (86%) as compared to the conventional instrument (62%). The simply-modified instrument facilitates the correct interpretation of serial radiographs.
authors.affiliation: Department of Oral Biology and Periodontal Disease, School of Dental Medicine, State University of New York, Buffalo.
authors.forename: L C
authors.initials: LC
authors.lastname: Carpio
authors.forename: E
authors.initials: E
authors.lastname: Hausmann
authors.forename: R G
authors.initials: RG
authors.lastname: Dunford
authors.forename: K M
authors.initials: KM
authors.lastname: Allen
authors.forename: L A
authors.initials: LA
authors.lastname: Christersson
mesh_terms: D000180:Acrylic Resins; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D000539:Alveolar Process / Q000000981:diagnostic imaging*; D006801:Humans; D016300:Radiography, Bitewing / Q000295:instrumentation* / Q000379:methods / Q000592:standards; D015203:Reproducibility of Results
chemical_list: D000180:Acrylic Resins