Fabrication of imaging and surgical guides for dental implants.

Research and experience have suggested that the success of dental implants depends on a well-developed and careful treatment plan approach. Historically, implant size and angulation were determined with the use of panoramic radiographs and clinical judgment during surgery. This occasionally resulted in mechanical and esthetic compromise. This article describes the step-by-step fabrication process for 4 different imaging and surgical guides. Set-up disks, which enhance the design and fabrication of guides, also are introduced. These guides are used in conjunction with cross-sectional tomography during the preimplant assessment of surgical sites.

Unrecognized carotid artery stenosis discovered by calcifications on a panoramic radiograph.

BACKGROUND: Approximately 730,000 strokes occur each year in the United States, costing an estimated $40 billion annually. One-half of all strokes are the result of atherosclerotic plaques found in the carotid artery. Such plaques frequently are heavily calcified and can be identified on a panoramic radiograph by the incidental finding of calcifications overlying the carotid bifurcation. CASE DESCRIPTION: The authors found that a 67-year-old asymptomatic woman had calcium deposits overlying both carotid bifurcation regions on a panoramic radiograph. Subsequent duplex ultrasonic examination indicated bilateral, high-grade carotid arterial stenoses. The patient underwent uneventful bilateral carotid endarterectomy. CLINICAL IMPLICATIONS: The patient had critical carotid arterial stenoses associated with significant risk of stroke that had not been identified otherwise. The findings on the panoramic radiograph led to appropriate and potentially life-saving treatment. While the positive predictive value of this finding has yet to be defined, the authors believe that calcifications overlying the carotid system region seen on panoramic radiography in an asymptomatic patient should be followed by formal evaluation of the carotid bifurcation.

Evaluation of a training program for detection of carotid artery calcifications on panoramic radiographs.

OBJECTIVE: To evaluate the effectiveness of the American Academy of Oral and Maxillofacial Radiology-sponsored training packet for identification of carotid artery calcifications on panoramic radiographs. STUDY DESIGN: Two examiners, who completed the training (trainees), examined 778 panoramic radiographs. The sample included 298 men, with a mean age of 66, and 480 women, with a mean age of 68. Findings were compared with those obtained by an oral and maxillofacial radiologist. A kappa statistic was used to determine agreement between the 2 trainees. The positive predictive value (PPV) of the program was estimated by comparing the trainees rating of disease status with an expert in case identification. RESULTS: Examiners 1 and 2 identified 99 and 78 positive cases, respectively. A kappa statistic of 0.87 (95% CI, 0.81-0.92) was obtained, indicating good interexaminer agreement. The expert identified 27 positive cases, resulting in a PPV of 34.6% (95% CI, 24.4-46.3). CONCLUSION: Although the training packet offers valuable training, it does not provide a high PPV, suggesting the need to modify it or to seek an expert opinion before classification of a patient as having calcification on a panoramic radiograph.

New York State Medicaid dental capitation plan.

The dental portion of the New York State Medicaid program has historically been limited in scope and access. While the Medicaid dental capitation plan introduced in recent years offers a new delivery system, it does not change fundamental flaws with the program. It continues to deny access to Medicaid recipients. This paper describes the state of Medicaid dental capitation enrollment in New York and its relationship to access to care--the principal idea behind DSSNY's class action suit against the state.

Correlation between planned prosthetic and residual bone trajectories in dental implants.

STATEMENT OF PROBLEM: The success of dental implant treatment relies on a well-developed treatment plan approach. Historically, implant placement was guided mainly by residual bone height and width, at times compromising prosthetic needs. PURPOSE: This study analyzed the amount of deviation between planned prosthetic trajectory and residual bone trajectory in different areas of the maxillary and mandibular dental arches, by using a tomographic survey in conjunction with imaging/surgical guides. METHODS AND MATERIAL: Ninety-two patients with a total of 235 implant sites were selected for the study. An imaging and surgical guide with a radiopaque indicator was constructed to determine the planned prosthetic trajectory. Cross-sectional tomograms were taken through the indicator at each implant site. The outlines of the available bone, planned prosthetic trajectory, and residual bone trajectory were traced, and the difference in the trajectory between the 2 trajectories was determined. RESULTS: Discrepancies between the planned prosthetic and the residual bone trajectories were greater in the mandibular molar area. This site was statistically different from other site groups at P =.05 (Tukey method). Statistically, all other site groups were not significantly different.

Computer intuition: guiding scientific research in imaging and oral implantology.

As the costs associated with clinical research and new drug development increase, it is incumbent upon us to develop alternative research methodologies. A new Computer Intuition (CI) program identifies literature-based evidence with the potential to generate a hypothesis that is most likely to be clinically confirmed regarding the cause of a disease or the questions being posed. The objective of this study was to demonstrate whether computer intuition can be used to guide scientific research in solving important biomedical questions. The establishment of CI as an alternative research methodology has the potential to accelerate the translation of basic science findings into clinical practice. The specific aim of this study was to develop a CI-driven hypothesis related to the controversial issue debating which radiographic imaging technology is most suitable for diagnostic purposes prior to the placement of oral implants. This hypothesis was then compared, in retrospect, with a known opinion established following a recent literature review on this issue. In his review of the literature, Frederiksen (1995) suggests that multiplanar reformatted computed tomography (CT) is the diagnostic imaging modality of choice prior to implant placement. To compare the CI hypothesis with Frederiksen's (1995) opinion, we subjected 34 relevant papers to CI analysis. The output consisted of clusters of important statements, phrases, and thought processes from the given dataset rated with the greatest potential to generate testable hypotheses. Both CI's output and Frederiksen (1995) indicated that CT scanning is the diagnostic imaging modality of choice prior to implant placement. Although the ultimate utility of CI is dependent on the successful testing of its derived hypothesis, this preliminary retrospective study suggests that CI might be useful in guiding scientific research.

A survey of faculty practices in U.S. dental schools.

In addition to providing a mechanism for maintenance and enhancement of the clinical skills of the faculty, intramural faculty practices are seen as an increasingly important source of revenue for dental schools. In this paper, we report on a survey conducted during academic year 1993/94 of United States dental schools as to the existence, organization, physical structure, finances and governance of their faculty practices. Results showed that all dental schools surveyed had some form of faculty practice or plan to establish a faculty practice in the future. The mean gross income of schools with established faculty practices in the 1993/94 academic year was 1.55 million dollars. Almost all sub-disciplines were represented in these faculty practices. More than 90 percent of the practices are housed within the dental school. The major cost to the faculty practice was staff salaries, with approximately 40 percent of the gross going to faculty reimbursement. Although 60 percent of the faculty practices surveyed were under the direct control of the dental school administration, a significant number of faculty practices were either corporations or partnerships. The results of the survey indicate a continuing trend towards the establishment of dental school-based intramural practices as a means of supporting the dental school budget.

Comparison between planned prosthetic trajectory and residual bone trajectory using surgical guides and tomography--a pilot study.

Implant treatment is a highly technical and complex form of dentistry. Research and experience have shown that the success of dental implant treatment relies on a well-developed treatment plan approach that takes into account factors such as systemic condition, anatomical landmarks, occlusion, shape and density of the jawbone, and type of implant system. Historically, once the tissue was reflected, implant placement was guided by residual bone height and width, using the trajectory that was compatible with the location and direction of available bone, at times compromising prosthetic needs. The purpose of this study was to measure the amount of deviation between planned prosthetic trajectory (PPT), perpendicular to the plane of occlusion, and residual bone trajectory (RBT) in different areas of the maxillary and mandibular dental arches, using tomography in conjunction with surgical guides. Twenty-five patients with a total of 66 implant sites were selected for this study. A surgical guide with a radiopaque indicator was constructed to determine the PPT. Cross-sectional tomograms were taken through the indicator at each implant site. The outlines of the available bone, PPT and RBT, were traced, and the difference in the angulation between the two trajectories was determined. Results showed discrepancies between the PPT and the RBT to be greater in the mandibular molar areas. Further study of such pre-implant diagnostic procedures is needed to understand the relation between the PPT and RBT, thus increasing the predictability of implant success.