Biomedical subjects

Donald A Tyndall

Publications and source records attributed to Donald A Tyndall.

10 recordsLinked to original sources

PubMed2006

In vitro assessment of cone beam local computed tomography for proximal caries detection.

OBJECTIVES: To compare the accuracy of local computed tomography (LCT) and conventional radiography for proximal caries detection and depth assessment. STUDY DESIGN: An in vitro model was used consisting of 20 extracted posterior teeth with 18 caries lesions. Local computed tomography slices were reconstructed in axial and parasagittal planes from 100 basis projections. Conventional radiographs were also acquired. Eight observers determined the presence and depth of caries lesions. Receiver operating characteristic analysis and weighted kappa statistics were used. RESULTS: Local computed tomography had a mean A(z) score of 0.82 (SD = 0.07) and conventional radiography of 0.79 (SD = 0.08; analysis of variance: P > .05). Interobserver agreement was moderate. The mean kappa for depth assessment was 0.68 (SD = 0.06) for LCT and 0.47 (SD = 0.08) for conventional radiography (analysis of variance: P < .05). Local computed tomography resulted in substantial and conventional radiography in moderate interobserver agreement. CONCLUSIONS: There is no difference between LCT and conventional radiography for proximal caries detection. Local computed tomography was more accurate for assessing caries lesion depth.

Adult↗

PubMed2006

In vitro assessment of local computed tomography for the detection of longitudinal tooth fractures.

OBJECTIVE: To test the accuracy of local computed tomography (LCT) in detecting longitudinal fractures in comparison with conventional periapical radiographs. STUDY DESIGN: Longitudinal fractures were induced in 30 of 60 teeth. The teeth were placed in a dry dentate mandible with soft tissue simulation. A laboratory LCT unit was used to acquire 180 basis projections with 1 degree separation along a 180 degree arc. Conventional radiographs served as the control modality. Correlated axial, coronal, and sagittal views were presented to 10 observers. The observers determined the presence of a root fracture by using a 5-point receiver operating characteristic confidence scale. RESULTS: The mean A(z) for LCT was 0.91 (SD = 0.07). The mean A(z) for conventional radiography was 0.70 (SD = 0.07). The difference between the modalities was statistically significant (analysis of variance: P < .0002), whereas the differences between the observers was not (analysis of variance: P = .319). CONCLUSION: Local CT significantly improves the detection of longitudinal fractures in vitro compared with conventional periapical radiography.

Analysis of Variance↗

PubMed2004

Interactive computer-assisted instruction vs. lecture format in dental education.

PURPOSE: The purpose of this study was to compare computer-assisted instruction (CAI) with lecture format using recent hardware and software advances. A pre- and post-test was used to determine student performance and instructional preference. In addition, a post-instruction survey was used to determine student learning preferences. METHODS: Seventy-five first-year University of North Carolina (UNC) dental students who were registered for the introductory radiology course were asked to participate. All agreed and were randomly placed in one of three groups: interactive CD only, interactive CD and lecture, and lecture only. The content of the multimedia instruction focused on intraoral radiography. A pre- and post-test was administered to determine if there was a significant difference between interactive CD and lecture formats, and an evaluation instrument was used to determine if there was a student learning preference between CAI and lecture format. Analysis of covariance and the sign test were used to determine significance (p<.05). RESULTS: There was no significant difference between pre- and post-test outcomes, indicating that similar learning took place using the interactive CD and/or lecture format. However, students preferred CAI to lecture format.

Analysis of Variance↗

PubMed2004

Extraoral imaging for proximal caries detection: Bitewings vs scanogram.

OBJECTIVE: The objective of this study was to compare the diagnostic accuracy of 3 extraoral imaging modalities with an intraoral bitewing radiograph for proximal caries detection. STUDY DESIGN: Three modalities of Cranex TOME scanograms, x-ray film and DenOptix photostimulable phosphor plates with and without digital enhancement, were compared with Insight intraoral radiographs for proximal caries detection. Nine observers evaluated images of the proximal surfaces of 45 extracted posterior teeth. The presence or absence of caries was scored using a 5-point confidence scale. The ground truth was determined from histological sections. Responses were evaluated by repeated measures analysis of variance (ANOVA) for areas under receiver operating characteristic (ROC) curves (A z ). RESULTS: Repeated measures ANOVA (at alpha = 0.05) demonstrated significant differences among modalities ( P = .041). Paired t tests with Bonferroni correction demonstrated that Insight was superior to only unenhanced digital scanograms ( P = .003). Mean A z scores (+/-SD) were 0.73 (+/-0.08) for Insight, 0.65 (+/-0.06) for screen/film scanogram, 0.64 (+/-0.04) for unenhanced digital scanogram, and 0.66 (+/-0.07) for enhanced digital scanogram. CONCLUSIONS: The performances of film-based and enhanced digital scanograms were not statistically different from Insight film for proximal caries detection. Unenhanced digital scanograms exhibited a statistically significant lower diagnostic accuracy than Insight film.

Analysis of Variance↗

PubMed2003

Tuned aperture computed tomography (TACT) for cross-sectional implant site assessment in the posterior mandible.

PURPOSE: This study was designed to optimize a new radiographic modality known as tuned aperture computed tomography (TACT) for cross-sectional imaging of implant sites in human dry mandibles. MATERIALS AND METHODS: Five imaging modalities were compared for image quality and measurement accuracy: (1) conventional hypocycloidal tomograms, (2) TACT images reconstructed using the average method produced using a linear x-ray source movement, (3) TACT images reconstructed using the average method produced using a multidirectional x-ray source movement, (4) minimally reconstructed TACT images without a fiducial marker at the site of interest, and (5) minimally reconstructed TACT images with a fiducial marker at the site of interest. RESULTS: The extended Mantel-Haenszel mean score statistic was used to investigate the influence of modality on subjective image quality. A statistically significant difference for certain types of TACT images and multidirectional tomography (P < 0.0001) was observed. Linear TACT and multmin TACT were rated as significantly better than other image modalities (P < 0.0009), whereas multidirectional tomography was rated as being significantly worse than other radiographic modalities (P < 0.0001). For the quantitative assessment, data were normalized and analyzed statistically through a paired-comparisons t test. For each modality, the accuracy for maximum height and height was significantly different from ground truth (P < 0.05). CONCLUSION: The qualitative data suggest that visibility of structures important to the choice of implant location and dimension were seen better with certain TACT methods. Quantitative differences from ground truth (actual measurements of the bone-absolute truth) were clinically negligible. TACT appears to offer the potential of superior image quality over the status quo.

Anatomy, Cross-Sectional↗

PubMed2002

Comparison of conventional and TACT (Tuned Aperture Computed Tomography) digital subtraction radiography in detection of pericrestal bone-gain.

Tuned Aperture Computed Tomography or TACT is a relatively new technique that transforms correlated two-dimensional images into a three-dimensional display. Associating TACT with digital subtraction radiography (TACT-DSR) may enhance its use in the detection of diseases. This study aims to assess observer performance in the task of detecting simulated bone-gain in periodontal defects, comparing conventional and TACT DSR. Buccal, lingual and proximal pericrestal bony defects in a human dry skull were imaged with and without increments of crushed-bone and wax mixtures using standardized vertical bitewing projections, acquired with an intraoral digital receptor in a tomographic X-ray machine. One hundred and twenty pairs of baseline and follow-up images were obtained for each imaging modality. Post-acquisition processing including image-registration, density-correction and subtraction operation were applied to both transmission images and TACT-slices. Eight calibrated observers evaluated the presence or absence of pericrestal bone-gain using a 5-point confidence scale. Details about the location of periodontal defects and the amount of bone-gain for each subtracted image were recorded and used in the statistical analysis. Observer performance and study design factors were analyzed by means of receiver operating characteristic (ROC) curve analysis and ANOVA. Mean values of areas under ROC curves for bone-gain detection performance were 0.82 for conventional DSR and 0.90 for TACT-DSR. TACT-DSR provided statistically superior detection performance of simulated periodontal bone-gain over conventional DSR for tooth-obscured defects (p = 0.001) and for the smallest bone mass (p = 0.024). The findings support TACT-DSR's potential to provide greater sensitivity and technique flexibility in detecting periodontal bone-gain than standard DSR.

Alveolar Bone Loss↗

PubMed2002

Evaluation of tuned-aperture computed tomography in the detection of simulated periodontal defects.

OBJECTIVE: The objective of this study was to compare the diagnostic efficacy of tuned-aperture computed tomography (TACT) and conventional film for the detection of simulated periodontal defects. STUDY DESIGN: Periodontal defects were created in 15 premolar-molar interproximal sites selected from 8 cadaver jaw segments. Ten observers viewed 45 image pairs (baseline and follow up) in 4 TACT modalities and film to assess the presence of defect. The TACT modalities were 1st and 2nd generation prototype systems (TACT-1 and TACT-2) with circular (C) and random (R) distribution patterns of source projection (TACT-1C, TACT-1R, TACT-2C, TACT-2R). Observer performance and related factors were analyzed by using receiver operating characteristic and analysis of variance. RESULTS: Mean A(z) values were 0.64 for film, 0.74 for TACT-1C, 0.82 for TACT-1R, 0.64 for TACT-2C, and 0.69 for TACT-2R. TACT-1R was significantly better than film (P < .001), TACT-2C (P < .001) and TACT-2R (P = .007). CONCLUSION: TACT-1R provided the best diagnostic performance in the detection of simulated periodontal defects among the 5 modalities compared in this study.

Algorithms↗

PubMed2002

Pre-clinical performance comparing intraoral film and CCD-based systems.

PURPOSE: The purpose of this study was to compare dental hygiene student radiographic performance using film and charge-coupled device (CCD) systems. Specific objectives were to compare the 1) number of technique errors, 2) error type, 3) retake frequency, and 4) learning experience using both systems. METHODS: Twenty-eight subjects exposed two 18-projection full series, one film-based, and one CCD-based system, on a manikin. One examiner, using standardized image quality criteria, evaluated all images. Each subject was assigned to one of four focus groups. Quantitative data were analyzed using ANOVA and Wilcoxon tests. Emic expressions and percentages were used to report qualitative data with themes supported by performance data. RESULTS: A greater number of technique errors occurred using the CCD system than the film system (p < 0.0001), with vertical angulation being the most common error (53%). Using the film-based system, 66% of the errors were due to incorrect horizontal angulation. Subjects exposed an average of 10 retakes per series using the CCD versus 3 retakes using film. Forty-four percent of the subjects felt their most common CCD errors were film placement and vertical angulation compared to 59% who believed horizontal angulation was the main technique error when using film. Difficulty placing the CCD sensor intraorally was expressed by 74%. The CCD system was reported to be beneficial for teaching theory (67%), with 59% preferring film for learning the psychomotor skill. CONCLUSION: In pre-clinical situations, the CCD system may be an effective tool for teaching technique. Radiographic errors are dependent on the type of image receptor used.

Analysis of Variance↗

PubMed2002

The influence of computer-assisted instruction on acquiring early skills in intraoral radiography.

The purpose of this study was to determine if there was a significant difference in the diagnostic quality of the initial full-mouth series (FMS) exposed by first-year dental students after viewing a Computer Assisted Instruction (CAI) module on radiographic technique as compared to those who did not and to determine if students who used the CAI module expressed a preference to using it and would recommend its use prior to exposure. Fifty-nine first-year dental students were randomly selected and assigned to two groups (students who did not view a CAI CD and students who did) before exposing their initial FMS on a Dental X-ray Training and Teaching Replica (DXTTR). For each radiographic series, a radiology faculty member determined the total number of error points based on performance criteria. The Wilcoxon Rank Sum Test was used to determine significance between the two groups, p = .05. After exposing the FMS, students in the second group completed a questionnaire to assess their preference for using the CAI CD. The Sign Rank Test was used to determine preference, p = .05. No significant difference in error points were found to exist between the two groups. Dental students who reviewed the CAI preferred using it and would recommend it to others before exposing their FMS.

Attitude↗

PubMedDate not supplied

Proximal caries detection: Sirona Sidexis versus Kodak Ektaspeed Plus.

This study compared the accuracy of intraoral film and a charge-coupled device (CCD) receptor for proximal caries detection. Four observers evaluated images of the proximal surfaces of 40 extracted posterior teeth. The presence or absence of caries was scored using a five-point confidence scale. The actual status of each surface was determined from ground section histology. Responses were evaluated by means of receiver operating characteristic (ROC) analysis. Areas under ROC curves (Az) were assessed through a paired t-test. The performance of the CCD-based intraoral sensor was not different statistically from Ektaspeed Plus film in detecting proximal caries.

Area Under Curve↗