Richard A. Weems

The Effect of a Knowledge-based, Image Analysis and Clinical Decision Support System on Observer Performance in the Diagnosis of Approximal Caries from Radiographic Images

The aim of this study was to investigate the effect of a knowledge-based image analysis and clinical decision support system (CariesFinder™, CF) on diagnostic performance and therapeutic decisions. The study material consisted of radiographic images of 102 approximal surfaces, 35 sound, 67 caries (25 caries and cavitated and 42 caries). Sixteen general practitioners were presented with (1) radiographic film images and (2) digital filmless images with the results of CF. The viewers were asked to respond whether approximal caries was present and whether a restoration was indicated. Responses were analyzed for accuracy, sensitivity, specificity and agreement. Further, the practitioners were ranked according to the accuracy of their restorative decisions and assigned to ten overlapping groups of 7 practitioners. For each group the diagnostic and therapeutic decisions were then examined for unanimity. The parameters of accuracy, sensitivity and specificity were then established for each group based on only unanimous, correct decisions. The diagnostic and therapeutic accuracy of CF alone was equal or superior to the decisions of the practitioners viewing film images alone. For unanimous decisions, CF alone was more accurate than the most accurate group of practitioners and made fewer incorrect decisions to restore non-cavitated surfaces than the practitioners. In general, dental practitioners viewing the results of CF significantly increased their ability to diagnose caries correctly, their overall diagnostic accuracy, and their ability to recommend restorations for cavitated surfaces. There was a decrease in the accuracy of their restorative decisions overall and in the specificity in particular.

The Use of a Computer-Based Image Analysis Program for the Diagnosis of Approximal Caries from Bitewing Radiographs

Approximal surfaces of 13 extracted molar and premolar teeth were classified directly and radiographically as sound or decayed. Eleven faculty dentists examined bitewing radiographs of the teeth and responded on a 5-point certainty scale, whether caries was present. Ten other faculty dentists used a computer-based program to examine the radiographs. For sensitivity, area under the receiver operating characteristic curve, and interexaminer agreement (Kappa), the computer-assisted faculty was significantly (p < 0.05) superior or equal to the unassisted faculty group.

Incidence of dental radiographic procedures during a 48-month population-based study of dentate adults.

OBJECTIVES The purpose of this population-based study was to quantify the incidence of radiographic procedures and the intervals between radiographic exposures. STUDY DESIGN The Florida Dental Care Study was a prospective cohort study of a representative sample of dentate adults. In-person interviews and dental examinations were conducted at baseline, with subsequent interviews every 6 months during 48 months of follow-up. Dental record information was abstracted afterward. RESULTS Thirteen percent of all dental procedures, and 42% of all diagnostic procedures, were radiographic. Annual person-level incidence of receipt of any radiograph was 48%. Incidence of specific types of radiographic procedures ranged from 5% to 30%. Among the 45% of the sample population who had had more than 1 bitewing procedure, 70% of the intervals between bitewing exposures were 1 year or longer. Receiving more than 1 full-mouth series or panoramic radiographic in any 24-month period was very rare. CONCLUSIONS Annual incidence of radiographic procedures was substantially higher than the incidence reported in previous studies based on responses by dentists to hypothetical situations, but was stable during the 4 years of follow-up. On the basis only of intervals between exposures, and not of clinical status on the day of service, there was no substantial evidence of inappropriately frequent radiographic examinations.

Density measurements of dentin by dual-energy radiography

OBJECTIVES The aim of this study was to apply the dual-energy radiographic technique to teeth and to soft tissue simulated with Lucite and report the visual and quantitative results. STUDY DESIGN High- and low-energy image pairs were exposed of aluminum and Lucite calibration wedges and human teeth sections. Reconstructed images of the calibration wedges and teeth sections were viewed and measured. RESULTS The aluminum reconstruction images accentuated the aluminum wedge and the teeth, whereas the Lucite reconstruction images minimized them. Correlations between the nominal direct and dual-energy measurements of the wedges and teeth thicknesses were found to be very good. The root-mean-square deviation of the dual-energy reconstructions from the measured nominal thicknesses was found to be no greater than 0.6 mm. CONCLUSION These results demonstrate the feasibility of using dual energy as a means of selective cancellation of unwanted tissues and the measurement of posterior tooth density.