The goal of this project is to develop a new technique for cross-sectional imaging of the mandibular body before dental implant insertion. The approach is based on reconstruction of a binary pattern from two x-ray projections by employing a combinatorial reconstruction algorithm. The short-term specific aims are intended to justify the in vitro applications of this technique.
Aim I. To perform a simulation study to determine at which x-ray energies there is sufficient contrast between bone and soft tissue for the mandible to be considered a binary object.
Aim II. a) To simulate a cross-sectional image of the mandibular body as an oval with a hole resembling the mandibular canal, using a higher resolution 200 x 200 matrix, and to test whether a similar pattern can be reconstructed from two orthogonal projections of an oval construct. b) To simulate the cross-section with a more complicated pattern and perform reconstruction.
Aim III. To test the technique using a practical dental x-ray device that has several non-ideal properties including nonparallel rays, polyenergetic x-ray spectrum, the heel effect, slightly different exposures, and possibly nonuniform detector response. b) To determine the magnitude of the errors resulting from these non-ideal properties and, where possible, develop and implement corrections. Preliminary study indicated that the reconstruction algorithm can reconstruct a similar pattern. The long-term goal is to use the techniques developed to acquire cross-sectional image of the mandibular body in dental practice before insertion of dental implants.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Small Research Grants (R03)
Project #
5R03DE010384-02
Application #
3425790
Study Section
NIDCR Special Grants Review Committee (DSR)
Project Start
1992-09-30
Project End
1994-09-29
Budget Start
1993-09-30
Budget End
1994-09-29
Support Year
2
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Washington
Department
Type
Schools of Dentistry
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Chen, S K; Hollender, L (1995) Linear unsharp mask filtering of linear cross-sectional tomograms of the posterior mandible. Swed Dent J 19:139-47
Chen, S K; Hollender, L (1995) Digitizing of radiographs with a flatbed scanner. J Dent 23:205-8
Chen, S K; Hollender, L (1994) Frequency domain analysis of cross-sectional images of the posterior mandible. Oral Surg Oral Med Oral Pathol 77:290-5
Chen, S K; Hollender, L (1994) Modulation transfer function of a digital dental x-ray system. Oral Surg Oral Med Oral Pathol 77:308-13