Biomedical subjects
Publications and source records attributed to A W Evans.
A case is presented of an ethmoid osteoma, which was discovered during the investigation of an orbital floor fracture. The osteoma was removed at the same time as orbital floor repair and special attention paid to preserving the medical canthal structures.
Temporomandibular joint (TMJ) saline aspirates, obtained from the upper joint space of 17 patients undergoing TMJ arthroscopy under general anaesthesia were assayed for the presence of nitrite, a stable metabolite of nitric oxide by a spectrophotographic method using the Griess reaction. Measurable levels of nitrites were found in the saline aspirates of both symptomatic and asymptomatic joints. There was no statistically significant difference between the two sides. The presence of nitric oxide metabolites in the asymptomatic joints has not been previously reported in the literature. This finding may represent a latent disease process in the symptomless joint.
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There is an increasing demand for methods to objectively assess a surgeon's competence. The purpose of this study is to test two evaluation methods that assess a surgeon's skills in the removal of mandibular third molar teeth. One method uses an objective checklist scale by which twenty components of the operation are judged as correct or incorrect. The second method is a global rating scale, that scores different aspects of performance, such as respect for tissue, number of manoeuvres, knowledge of procedure and instrument handling. Using these two methods, assessors judged the removal of 22 mandibular third molar teeth by 17 different surgeons. Good inter-rater reliability was achieved using both scales. A greater preference was expressed for the global rating scale for assessment and for the objective checklist scale for guiding feedback in training. Scales such as these need to be developed for, and tested on, different surgical procedures in order that credible assessment of surgical skills can be obtained.
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Differences are examined in assessment and self-assessment scores, in oral and maxillofacial surgery trainees and MSc postgraduates, following the surgical removal of lower third molar teeth. This study found evidence of a surprising and worrying over-rating of their own surgical skills by many trainees and postgraduates.
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The growing demand for assessment in all aspects of surgical competencies will inevitably embrace the whole of dental surgery. The aim of this paper is to review the literature and discuss some of the issues that will have to be addressed as objective assessment of the surgical dentists' skills is introduced. The paper reviews what is meant by competence and how we assess it, with particular emphasis on practical and technical skills. Specific methodologies for assessing competence are described including, as illustrations, two means of assessing the removal of lower wisdom teeth. The evaluation of competence in the workplace is discussed together with the difficulty in assessing important attributes such as attitude. It concludes that the assessment of competence is a valuable tool in its own right and a means of demonstrating to the public the continuing commitment of the profession to the highest possible standards. However assessment will be very time consuming and to be worth while we must ensure that it is done in a way that produces clear and unambiguous benefits and solves real problems.
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OBJECTIVE: This article reviews osteosarcomas of the jaws referred to the Department of Oral Pathology, Eastman Dental Institute, for histologic diagnosis during the 30 years from 1968 to 1998, to compare the clinical behavior of the tumors, to assess how they differ from the reported characteristics of tumors from other sites, and to report on observations of clinical and diagnostic significance. STUDY DESIGN: The clinical, radiographic, and histopathologic records of 25 patients were obtained for retrospective review. Supportive and follow-up clinical and histopathologic material was obtained from the referring clinicians. RESULTS: The mean age of presentation of the primary lesions was 36. 9 years (range, 10-87 years) with a slight female predilection. The most common presenting features were swelling, pain, ulceration, or a neurologic deficit. The radiographic appearance of the lesions was mixed with areas of radiopacity and radiolucency. Histologically, the lesions ranged from those dominated by immature bony trabeculae separated by a cytologically bland stroma to high-grade, cellular lesions with regions of marked atypia and mitotic activity. Most had areas of chondroid formation, in addition to neoplastic osteoid. The main complication was local recurrence. Metastasis was rare and occurred as a solitary process or at a late stage in the disease progression. This was in contrast to lesions metastatic to the jaws, which were higher grade in appearance and had metastasized widely, early in the disease process. Primary osteosarcoma occurring in patients with a history of radiotherapy was typically more aggressive. CONCLUSION: Primary osteosarcomas of the jaws are a group of lesions distinct from those occurring in the long bones. Osteosarcomas of the jaw arising in a former radiation field may be a discrete group of lesions with a more aggressive behavior pattern.
The ability of sera to recognise secreted macromolecules of Staphylococcus aureus was examined by ELISA and Western immunoblotting. Individual secreted proteins were also studied using both human sera and sera from rabbits immunised with secreted macromolecules. Patients sera showed a wide range of IgG antibody titres to secreted macromolecules and whole bacteria. Controls showed a significantly lower IgG response. Western immunoblotting revealed that a significant number of secreted proteins were recognised by circulating IgG antibodies. Surprisingly, both the sera from controls and from patients recognised similar macromolecules including a number of potential virulence factors. The major difference was in the IgG binding to a 16-kDa component, which was recognised by the majority of the sera from infected individuals, but only by a small number of sera from healthy controls. The higher incidence of antibodies recognising the 16 kDa component may be related to our earlier finding that the major bone resorbing component of S. aureus is a heterodimeric protein containing a 16-kDa subunit, the activity of which could be blocked by sera.
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This paper considers estimates of the number of fatalities per year on rail lines operated by British Railways that could be expected to be saved by the installation of automatic train protection, based on historical data. The authors' preferred estimate is 3.66 fatalities per year, with an estimated 95% confidence interval of 1.44-5.89. It is possible to find orthodox probability distributions that fit the distribution of numbers of fatalities well. FN-graphs are not a suitable means of fitting such distributions.
Oral cancer and precancer appear to fulfil many of the criteria for a disease suitable for mass screening. Several commercial organisations in the UK have introduced screening for their employees. One program has been formally evaluated over the course of 1 yr. Of 553 company headquarters staff aged > or = 40 yr, 292 (53%) responded to the well-publicised screening invitation and received a simple clinical examination of the oral mucosa from one of two company dentists. In addition, 17 staff were screened from a separate company work-site. After screening, subjects were examined independently by an oral medicine specialist with access to the relevant diagnostic aids. The dentists' screening decisions were validated against the specialist's definitive diagnoses (the 'gold standard'). The true prevalence of subjects with lesions diagnosed as positive (white patch, red patch or ulcer of greater than 2 weeks' duration) was 17 (5.5%). Overall, sensitivity was 0.71 and specificity, 0.99. The compliance rate to screening among headquarters subjects in seven occupational categories did not differ significantly from the occupational profile for all headquarters personnel. Estimates of relative risk of a positive diagnosis were calculated by logistic regression for five independent variables; gender, age, moderate smoking, heavy smoking, and smoking combined with greater than low risk alcohol consumption. Only heavy smoking (> or = 20 cigarettes per day) produced a significant odds ratio (3.43, P < 0.05).
This paper discusses three approaches to the evaluation of transport safety measures--labelled cost-benefit analysis, industrial risk assessment and the elimination of all avoidable accidents--and the institutional settings in which each is dominant. This paper considers the application of these approaches primarily to road and rail safety measures in Great Britain. It is suggested that the elimination of all avoidable accidents should be rejected because of its large and open-ended resource requirement, but it is acknowledged that this is difficult because it implies the acceptance of avoidable accidents on public transport systems. The paper suggests a framework drawing on the other two approaches, in which cost-benefit analysis is combined with a limit on the tolerable risks to individuals.