PubMed Health⌕ Search

Biomedical subjects

L Christersson

Publications and source records attributed to L Christersson.

7 recordsLinked to original sources
PubMed1989

Effect of x-ray beam vertical angulation on radiographic alveolar crest level measurement.

Utilizing intraoral radiographs of human skulls taken at known vertical angulation, we have demonstrated that expression of the crest level as a distance between cej and the crest is as accurate as a ratio of bone height to root length. The degree of inaccuracy of either of these measures is related to the magnitude of the angular deviation of the x-ray beam from 90 degrees. Angular deviation can be estimated from calculation of a cusp height score (ratio of lingual cusp height to buccal cusp height x 100). Based on the analysis of cusp height scores it was determined that the x-ray beam angulation for posterior bitewings ranged between 90 degrees and 80 degrees whereas for posterior periapicals the angulation range was between 90 degrees and 70 degrees. Therefore, it is recommended that, for longitudinal studies of bone height, measurements of the crest to cej distance, particularly in the region of the molars, be made utilizing bitewing radiographs. For the premolar and incisor regions, deviation of the vertical angulation of an x-ray of up to 20 degrees from a 90 degrees baseline resulted in little, if any, change in crest level by either one of the two measures used. An appendix is provided for the theoretical modeling of the types and magnitude of change in crest level observed for projection images of different anatomical configurations.

Alveolar Process↗
PubMed1985

Usefulness of subtraction radiography in the evaluation of periodontal therapy.

Subtraction radiography, a sensitive and accurate technique for identifying alveolar crestal change from standardized pairs of radiographs, is useful in monitoring periodontal therapy. One half of the radiographs were found to be appropriate for subtraction analysis using present technology for taking standardized radiographs. The criterion for usability was identical interpretation of subtraction images made in duplicate from a pair of radiographs. A set of radiographs was analyzed by subtraction radiography as well as by measurement of alveolar bone-crest height. Subtraction radiography was found to be more sensitive in detecting change. Whereas 53% pairs of radiographs showed a change on subtraction radiography, only 14% showed a change in crest height. Comparison of change by subtraction radiography and probing attachment level showed an overall correlation. Since these two measures assess different aspects of the periodontium, perfect correlation was not expected.

Alveolar Process↗