PubMed Health⌕ Search

Biomedical subjects

John B Ludlow

Publications and source records attributed to John B Ludlow.

9 recordsLinked to original sources
PubMed2006

The effect of lighting conditions on caries interpretation with a laptop computer in a clinical setting.

OBJECTIVE: To test the null hypothesis of no difference in caries detection in dim, bright, and hooded environments for laptop viewing of intraoral radiographs. STUDY DESIGN: Extracted posterior teeth were imaged with posterior bite wing geometry by using storage phosphor plates. Images were displayed on a laptop computer placed in 3 lighting environments. Six dental students and 6 faculty observers scored the caries status of proximal surfaces. Responses were compared to histologic ground truth by using receiver operating characteristic (ROC) analysis and other measures of accuracy. Performance was also compared to photometer-measured light levels and time spent in observation. RESULTS: ROC A(Z) was significantly higher for faculty using hooded displays (0.87) than in a bright clinical environment (0.79; P = .04). Student performance was highly variable and not significantly different in any of the lighting environments. CONCLUSION: The ability to detect caries by experienced clinicians may be improved by hooding laptop displays in bright clinical environments.

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↗
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↗
PubMed2003

A comparison of slide/audiotape and Web-based instructional formats for teaching normal intraoral radiographic anatomy.

PURPOSE: The purpose of this study was to evaluate the relationship between individual learning styles, test performance, and attitudes toward the use of Web-based self-instruction and slide/audiotape self-instruction METHODS: Participants consisted of 33 junior, first-year dental hygiene students enrolled in a university-based dental hygiene program. A stratified random allocation (by gender, English as a second language, and prior dental experience) and random number table were used to assign participants into one of two groups. Group one studied the mandibular arch using the slide/audiotape format and the maxillary arch using the Web-based format, and group two studied the mandibular arch using the Web-based format and the maxillary arch using the slide/audiotape format. A post-test was taken at the completion of each instructional format. The Kolb Learning Style Inventory was used to assess preferred learning styles, and a written survey was used for instructional format preference. Descriptive analyses, Pearson correlations, and unpaired t-tests were used to analyze the data. RESULTS: Thirty-one subjects completed the study. By group, no difference in mean post-test performance was seen based on the sequence or order of instructional method (P > 0.05) or by arch (P > 0.05). No difference in post-test performance based on Web-based and slide-tape instructional methods was seen. Predominate learning style did not predict preference of instructional format nor were they correlated with post-test scores. However, almost 70% of all participants reported that they preferred using the Web-based format to the slide/audiotape. CONCLUSIONS: A variety of learning styles and preferences may be accommodated when substituting Web-based self-instruction for slide/audiotape self-instruction in normal radiographic anatomy.

Adult↗
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↗
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↗