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Biomedical subjects

D G Wastell

Publications and source records attributed to D G Wastell.

At least 19 recordsLinked to original sources
PubMed1991

Glove use in clinical practice: a survey of 2000 dentists in England and Wales.

Attitudes to glove wearing by dentists practising within the NHS Regulations were tested by means of a questionnaire distributed to 2000 dentists in England and Wales. The response was 76.5%. The results indicate that 68% of the respondents wore gloves routinely for all patients and procedures, 3% never wore gloves, while the remainder (29%) wore gloves for only selected patients or selected procedures. Reasons given for not wearing gloves routinely included problems of comfort, loss of tactile sensation and the risk of cross-infection, which was perceived to be small. Of the routine glove wearers, only 12% changed gloves between patients, cost being considered to be a factor by 57% of respondents who used gloves for more than one patient. The results indicate that the respondents practising and personal details had an influence on the pattern of glove wearing, with single-handed practitioners and those who graduated before 1979 being less likely to wear gloves routinely. Comparison with the findings of earlier studies of similar type suggest that there is increased awareness in the dental profession of the necessity for glove wearing, but that there is still a need to encourage routine glove use, especially amongst certain groups of GDPs.

Age Factors↗
PubMed1991

A comparison of two splints in the treatment of TMJ pain dysfunction syndrome. Can occlusal analysis be used to predict success of splint therapy?

Controversy surrounds the diagnosis and treatment of TMJ pain dysfunction syndrome (TMJPDS). This is also reflected in the widely divergent recommendations in splint design. A study was undertaken to examine the comparative success rates of treatment by two occlusal splints with apparently diametrically opposed modes of action and to determine whether there were any factors which could be utilised to predict the success of splint therapy. Sixty-eight TMJPDS patients were randomly distributed into one of two comparable groups and were treated solely with an occlusal splint for night time wear. One group was treated with a stabilisation splint (SS) and the other with a localised occlusal interference splint (LOIS). The success rate at review with the SS was 67.6% and with the LOIS was 80.9%. This difference was not statistically significant. Pretreatment occlusal analysis demonstrated three indicators of successful splint therapy which appeared to be independent of design. These were the absence of centric relation occlusion, the existence of non-working side interferences and an absence of ideal anterior guidance.

Chi-Square Distribution↗
PubMed1990

Trigeminal somatosensory evoked potentials: technical parameters, reliability and potential in clinical dentistry.

Various parameters of the short-latency trigeminal somatosensory evoked potential (TSEP) waveform were investigated in 12 healthy volunteers. The waveform was found to comprise two principal components at 23 (N1) and 39 (P1) ms and to show a significant contralateral dominance. Varying the stimulus strength significantly affected the amplitudes but not the peak latencies. The waveform pattern was maintained irrespective of whether the reference site was Fpz or Cv7. The peak latencies of N1 and P1 were found to be very reproducible. To a lesser extent, N1-P1 amplitude was also reproducible. The results show that clear and reliable TSEPs can be conveniently generated at the pain threshold intensity, and that they could be suitable for clinical investigations of lesions involving the trigeminal pathway. The clinical application of TSEPs has helped in treatment planning for patients with lesions of branches of the trigeminal nerve. Three cases are presented in which the TSEP confirmed the presence of the lesion, and was used to forecast its prognosis.

Adult↗
PubMed1989

A double-blind cross-over trial of a mucin-containing artificial saliva.

A double-blind, five phase, cross-over clinical trial was used to compare a mucin-based artificial saliva (Saliva Orthana) with its non-mucin base and water. Thirty patients, acting as their own controls, took part. Saliva Orthana offered significantly greater relief from xerostomia compared with its base or water, and was significantly better at relieving soreness than water. In terms of overall preference, it was ranked significantly higher than either alternative.

Adult↗
PubMed1989

Image analysis of radiolucencies in approximal enamel: a comparison of xeroradiographic and conventional film images.

Xeroradiographic and conventional film bitewing images of radiolucencies in approximal enamel were compared using a computer-aided image analysis system. Densitometric analysis of the conventional film types used in the study showed that the "lead foil free" film exhibited lower overall density when compared with conventional D-speed film. Computer-aided image analysis of radiolucencies in approximal enamel found that xeroradiographs depicted a higher degree of demineralization and a larger area than conventional radiography with the "lead foil free" film.

Adolescent↗
PubMed1989

Spectral analysis of the masseter and anterior temporalis: an assessment of reliability for use in the clinical situation.

The electromyogram (EMG) of contracting muscles can be analysed in the frequency domain by spectral analysis. However, there is a need to establish the reproducibility of spectral parameters such as mean power frequency (MPF). This study examined the variation of MPF (masseter and anterior temporalis) between and within recording sessions. The MPF was found to be significantly reliable for both muscles, but considerable within-subject variation was found despite comprehensive measures to standardize recording methods and conditions. It is concluded that MPF may have clinical application in the diagnosis and treatment of patients with facial pain arising from muscle dysfunctions, but caution should be exercised in interpreting small changes in frequency, given the inherent variability of MPF.

Adult↗
PubMed1988

A role for computers in the management of dental education.

The dental educator confronts increasing demands for technically demanding training against a background of factors working to reduce the clinical experience of students: less dental disease, new educational emphases and greater cost-consciousness. A computer system is described which has run successfully for 7 years in the Department of Conservative Dentistry at Manchester University. This system enables better use to be made of declining teaching resources; it allows the department to make more accurate and timely assessments of student progress; it can also provide information on current workload and clinical commitments. Some possible lines of future development are discussed, including use of the system to collect Korner data-sets and to support a more integrated approach to treatment.

Computers↗
PubMed1988

Can past academic criteria predict students at risk of future failure?

A significant minority of medical and dental students fail their undergraduate courses. Early warning systems (EWSs) have been developed in some areas of higher education to predict 'at-risk' students at an early remedial stage. An attempt is made to develop an EWS to predict failure in the bacteriology component of the Batchelor of Dental Surgery course at Manchester Dental School. A system based on class tests and previous end-of-year performance is derived which is used to predict those students likely to fail or fall in the bottom 20-25% in their finals examination. The predictors are combined by a simple equal weights method, which is found to have the same predictive power as using multiple regression. Failure was correctly predicted in 60% of cases, at the expense of 71% false alarms. The high number of false alarms reflects the low failure rate rather than the lack of predictive information. The need for effective cross-validation of EWSs is discussed; many previous studies have not been tested on independent data.

Achievement↗
PubMed1987

The numerical approach to classification: a medical application to develop a typology for facial pain.

Applications of numerical taxonomy in medicine are relatively rare. We describe an application in which a new typology is developed for the classification of pain distribution in patients with temporomandibular pain dysfunction syndrome. The methodology of the numerical approach is presented and key issues are highlighted, especially relating to validation of taxonomic structure. From the dendrogram obtained by Ward's hierarchical method, five pain groups are distinguished which relate systematically to anatomy and are clinically meaningful. Cluster structure is subjected to a battery of reproducibility tests and is found to be broadly reproducible for different algorithms and sub-samples of subjects. Finally, the new typology is shown to have heuristic value in providing fresh insight into the nature of a complex syndrome.

Algorithms↗
PubMed1987

Applications of trigeminal somatosensory evoked potentials (TSEPs) in oral and maxillofacial surgery.

The initial results of trigeminal somatosensory evoked potentials (TSEPs) which were recorded in 17 patients, age range 16-64 years, presenting with established unilateral sensory impairment to the face or oral cavity, are described. Nerve potentials were evoked by stimulation of the normal healthy side and compared with those recorded from the side with disturbed sensation. The recorded waveforms allowed identification of a prominent sequence of events. Significant increases in the latencies compared to the events previously determined in normal subjects at 20, 30 and 39 msec. were found, and considered to be associated with clinical sensory impairment.

Adolescent↗
PubMed1987

A simple randomisation procedure for validating discriminant analysis: a methodological note.

Because the goal of discriminant analysis (DA) is to optimise classification, it designedly exaggerates between-group differences. This bias complicates validation of DA. Jack-knifing has been used for validation but is inappropriate when stepwise selection (SWDA) is employed. A simple randomisation test is presented which is shown to give correct decisions for SWDA. The general superiority of randomisation tests over orthodox significance tests is discussed. Current work on non-parametric methods of estimating the error rates of prediction rules is briefly reviewed.

Random Allocation↗
PubMed1987

Trigeminal somatosensory evoked potentials. A review of the literature as applicable to oral dysaesthesias.

Oro-facial sensory impairment is a common event following third molar extractions, osteotomies and maxillo-facial trauma. Trigeminal somatosensory-evoked potentials (TSEPs) may offer an objective means of assessing neuronal function in such cases. TSEPs may be recorded non-invasively in man following peripheral stimulation of the trigeminal nerve, the principal nerve of oro-facial sensation. TSEP recording has gained popularity over the last decade and it is thus timely to review experimental methods and proven clinical applications in the light of recent interest in this technique within oral and maxillo-facial surgery.

Animals↗