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Biomedical subjects

S E Stheeman

Publications and source records attributed to S E Stheeman.

9 recordsLinked to original sources
PubMed1996

Room for improvement? The accuracy of dental practitioners who diagnose bony pathoses with radiographs.

OBJECTIVES: The impact of any effort aimed at improving diagnostic accuracy by improving clinical decision making in diagnostic radiology will be limited by the ability of the clinician to correctly recognize the presence of abnormalities on radiographs. We carried out a study designed to examine whether dentists are able to correctly identify various kinds of periapical bone lesions visible on intraoral radiographs and diagnose their pathologic nature. STUDY DESIGN: General dental practitioners (n = 98) assessed 32 radiographs that showed either normal bone (10) or one abnormality (22) in the periapical bone. The "gold standard" for pathosis was histopathologic analysis. The dentists were asked to judge for the presence of an abnormality and to decide whether an active pathologic process was present. RESULTS: On average dentists identified 81% of all visible abnormalities correctly. Subsequently, they diagnosed 59% of all the pathologic cases correctly. Dentists, however, incorrectly identified 55% lesions on radiographs when experts had stated that no abnormality was visible. CONCLUSION: There is room for improvement of diagnostic accuracy of bony pathology.

Alveolar Process↗
PubMed1995

Diagnostic confidence and the accuracy of treatment decisions for radiopaque periapical lesions.

The periapical radiograph is a tool used in the diagnosis of periapical bone pathology. Radiographic diagnosis might therefore influence endodontic treatment planning and the quality and the cost of dental health care. The hypotheses were tested that (1) the subjective prevalence of a lesion would be associated with the accuracy with which it is diagnosed, (2) 'confident dentists' would be as accurate in their diagnosis as 'doubtful dentists' and (3) the diagnostic confidence of dentists for the diagnosis of periapical pathology would not influence their treatment planning. It was found that the probability of an appropriate treatment decision increased when dentists were relatively confident about a diagnosis. The results showed, furthermore, that the accuracy of diagnostic decisions increased when the dentist's confidence about a particular decision was high. Ways to increase diagnostic accuracy of radiopaque periapical pathology are proposed as a result of this study.

Clinical Competence↗
PubMed1995

Does radiographic feature recognition contribute to dentists' diagnosis of pathology?

OBJECTIVES: To measure the degree to which dentists can accurately identify radiographic features and use their findings in the diagnosis of three lesions. METHODS: Fourteen radiographic examples were used in this study and five features derived from the literature: border sharpness, border radiopacity, lesion shape, lesion radiopacity and root contact. A 'silver standard' for the presence of the features in the radiographic images of the lesions was established by expert observers; and a diagnostic 'gold standard' based on the histopathology of the lesions was available. Dentists scored each image according to these features and gave their diagnosis. RESULTS: When dentists made different subjective diagnoses for a case, significant differences were found in the extent to which features were reported to be present. The degrees of presence of border sharpness (21%) and border radiopacity (46%) measured using the 'silver standard' were significantly related to the diagnosis of osteosarcoma. CONCLUSIONS: Radiographic information is not used to its full extent and improvement in the recognition of features and the cognitive use of this radiographic information in the diagnostic process could improve diagnostic accuracy.

Analysis of Variance↗
PubMed1995

An approach to the development of decision support for diagnosing pathology from radiographs.

OBJECTIVES: Large inter-observer variation has been reported in oral radiology. Providing observers with a checklist prompting them to focus on specific radiographically visible features with known relevance to the diagnosis has been shown to improve diagnostic accuracy. We intended to investigate whether diagnostic accuracy for bony pathology could be improved by a computerized decision aid. The decision support provided the user with radiographic reference images for the degree of presence of a radiographic feature (such as radiopacity) and structured the use of diagnostic knowledge. METHODS: Twenty-seven general dental practitioners participated in the study. They diagnosed seven radiographic cases of bony pathology using a prototype decision aid and seven other cases unaided. For each radiograph the dentists assessed the degree of presence of five radiographically visible features which had been selected from the literature oral radiology because of their use in describing, radiographically visible bony pathology. The dentists' assessments of degree of feature presence, and their diagnoses, were recorded. Histopathology was used as a diagnostic 'gold standard'. The degree of presence of the features in the radiographic images was also assessed by an independently selected panel of expert oral radiologists in a Delphi consensus procedure. RESULTS: Determination of the degree of presence of three radiographically visible features assessed by the dentists using the prototype decision aid was significantly improved (by up to 12%) compared to the results of their unaided assessments. The diagnostic accuracy of one-third of the dentists was also improved. CONCLUSION: The use of reference images can improve dentists' assessments of the degree of feature presence.

Analysis of Variance↗
PubMed1995

Use of the Delphi technique to develop standards for quality assessment in diagnostic radiology.

The Delphi technique is a method for obtaining answers to questions that are issues of uncertainty even to experts. The aim of this study was to use the Delphi technique to develop two standards for the assessment of the diagnostic performance of dentists using radiographs. Two Delphi consensus procedures were initiated to determine the presence of visible abnormalities on radiographs and their pathological nature. A panel of expert radiologists was independently selected. This panel reached consensus on the items of both Delphi procedures through a number of rounds of written correspondence. The outcomes of the procedures were compared to a histopathologic norm for the presence of pathology. The group procedure was described as well as tested for dominance on part of any of the individual panellists. It was found that up to 98 per cent agreement occurred among the majority of panellists on items of the procedures. The panellists were significantly better than dentists in the diagnosis of pathology (P < 0.05) and kept improving during the process of consensus formation. In neither of the Delphi procedures was the judgement of any panellist dominant (P > 0.4). It is concluded that, if carefully controlled, the Delphi technique may be used in the development of diagnostic standards in oral radiology.

Chi-Square Distribution↗
PubMed1994

Image quality of direct digital intraoral x-ray sensors in assessing root canal length. The RadioVisioGraphy, Visualix/VIXA, Sens-A-Ray, and Flash Dent systems compared with Ektaspeed films.

The Trophy RadioVisioGraphy model 32000 system in Normal Mode, the Trophy RVG-PC in Normal and Archive Mode, the Gendex VIXA/Visualix, the Regam Sens-A-Ray, and the Villa Flash Dent in High-Resolution Mode and Normal Mode were compared with respect to the visibility of endodontic files. Kodak Ektaspeed film served as the reference. An acrylic embedded human skull was prepared for taking radiographs with endodontic files (Kerr files size 10 and size 15) on full root length and 1.5 mm short in upper and lower premolars and molars. Possibilities for enhancement of the digital images were not studied. Receiver operating characteristics curves were derived and the areas under the curves were averaged and compared using Student's t test statistic (p < 0.05). Kodak Ektaspeed film gave acceptable results for both file sizes. Both Trophy RVG units in Normal Mode and the Regam Sens-A-Ray system gave results above the areas under the curves equals 0.95 for the size 15 files. For the size 10 files the values of the areas under the curves of all sensors systems were below this threshold. It is concluded that both RVG units in Normal Mode and the Sens-A-Ray system render a comparable result with conventional radiography in determining root canal length with the use of a size 15 files. All sensor systems were unacceptably inferior to film images when size 10 files were used.

Dental Pulp Cavity↗
PubMed1993

Blind chance? An investigation into the perceived probabilities of phrases used in oral radiology for expressing chance.

The necessity for numerical probabilities in oral radiographic diagnosis is increasing, due to recent developments in computer-aided diagnosis, decision analysis, informed consent and medical litigation. These numerical probabilities are only partly available from current texts on oral radiology, where they are often expressed by ill-defined, semiquantitative phrases. Therefore, in this study 30 phrases expressing the probability of a relationship between a diagnosis and its symptoms were taken from a selected textbook on oral radiology. Seven oral radiologists from the USA and the Netherlands scored each of these probabilistic phrases on a 20-cm visual analogue scale. Low intraradiologist and high interradiologist variation was found. Because the high variation among authors of texts on oral radiology in interpreting probability information could have a negative influence on their ability to transfer unambiguous information to their readers, it is recommended that the use of semiquantitative phrases in oral radiology is restricted to five probability groups.

Humans↗
PubMed1992

Expert systems in dentistry. Past performance--future prospects.

Expert systems are knowledge-based computer programs designed to provide assistance in diagnosis and treatment planning. They assist the practitioner in decision making. A search of the literature on expert system design for medical and dental applications was carried out. It showed an increase in the number of articles on this subject. Between 1984 and 1991, 608 articles have been published in medical journals and two in dental journals. Because it is likely that this development will influence dental practice in the future a critical review of medical literature on the topic has also been carried out. A number of general principles are described to give the dental practitioner some insight into how expert systems work. A set of criteria have been formulated from the medical literature which expert systems should meet. These requirements are also applicable to dentistry and may be used to judge dental expert systems. In the last part of the paper the features of several dental expert systems developed in the past decade are described in the light of these criteria. It is concluded that in the future more attention should be paid to the development and evaluation of expert systems in the clinical setting. Only well-designed and properly evaluated expert systems can be expected to earn a place in everyday practice.

Dentistry↗