Biomedical subjects

T V Macfarlane

Publications and source records attributed to T V Macfarlane.

33 records · Page 2Linked to original sources

PubMed2001

Three phosphor plate systems and film compared for imaging root canals.

AIM: The aim of this study was to compare three phosphor plate intraoral imaging systems (Digora (DA), Digident (DT), Denoptix (DX)) and E-speed conventional film (CF) for the imaging of root canals. METHODOLOGY: Sixty extracted permanent teeth were exposed using CF, DA, DT and DX. The length of root canal visible from its most apical extent to a line drawn at the level of the cementoenamel junction was measured and this was expressed as a percentage of the distance between the radiographic apex and the cementoenamel line. All images were examined concurrently by two examiners. Films were viewed under standardized conditions and DA, DT and DX images were viewed directly from the monitor screen. The images on the monitor were enhanced to give the subjectively clearest image. RESULTS: The mean percentage of canal visible on CF was 90%, DA 78%, DT 81% and DX 83%. The difference was significant for CF-DA (P < 0.001) and CF-DT (P = 0.001). There was no statistically significant difference for CF-DX or between any of the three phosphor plate imaging systems. CONCLUSIONS: It is concluded that a greater length of root canal was visible on conventional film than on three phosphor plate imaging systems and that this may be of clinical significance.

Analysis of Variance↗

PubMed2000

The influence of viewing conditions on radiological diagnosis of periapical inflammation.

OBJECTIVES: To determine the effect of viewing conditions upon diagnosis of early periapical inflammatory pathosis on intra-oral radiographs, and to examine the effect of observer experience upon diagnostic performance in this task. METHODS: 50 observers examined 18 periapical radiographs using three different viewing conditions (room lighting; viewing box; viewing box with x2 magnification and masking). Their diagnoses were compared with an 'expert' diagnosis provided by repeated viewings of the films by two dental radiologists. Sensitivities and specificities were determined. RESULTS: When 'ideal' viewing conditions were used, optimal sensitivity (78%) and specificity (78%) were obtained. Use of a viewing box was associated with significantly higher specificity than the use of room lighting (P = 0.0016). Use of masking and x2 magnification was associated with significantly higher sensitivity than a viewing box alone (P = 0.004). There were few significant differences in diagnostic performance between observers, but qualified dental staff had significantly higher specificities than 4th year (P = 0.01) and 5th year (P = 0.01) students when a viewing box was used alone. CONCLUSIONS: This study on early periapical inflammatory pathosis gives support to guidelines which recommend the use of a viewing box, x2 magnification and masking for interpreting intra-oral radiographs. It also suggests that observer experience may influence interpretation of early periapical pathosis.

Clinical Competence↗

PubMed2000

The effects of midazolam and flumazenil on psychomotor function and alertness in human volunteers.

OBJECTIVE: To investigate the effect of midazolam and flumazenil on psychomotor function and alertness in human volunteers. DESIGN: Randomised, double-blind, cross over study. METHODS: Intravenous flumazenil was administered to sedated and non-sedated healthy human volunteers, in doses typical of those used clinically to induce sedation with midazolam and for reversal with flumazenil. Subjective assessment of alertness and objective measures of psychomotor function using light reaction time and the Maddox wing were made over a 1 hour period. RESULTS: Seven males and seven females each attended four experimental sessions. Psychomotor function was impaired by midazolam but there was some individual variation to this response. All sedated subjects receiving flumazenil had significantly improved alertness and psychomotor function when compared with those subjects who received placebo. Mean alertness (P < 0.01) and light reaction time (P < 0.05) showed significant improvement and returned to baseline by 60 minutes. Stability also showed significant improvement (P < 0.05) but did not return to baseline by 60 minutes. There was no significant effect on psychomotor function or alertness when the antagonist flumazenil was administered in the absence of the agonist midazolam. CONCLUSION: An earlier discharge time based on subjective assessment of alertness is not advocated for patients whose intravenous midazolam sedation is reversed with flumazenil.

Adult↗

PubMed2000

Patterns and appropriateness of referral from general dental practice to specialist oral and maxillofacial surgical services.

In this study we investigated patterns of referral and appropriateness of referrals to specialist oral and maxillofacial surgery services, using postal questionnaires and referral letters. The most common reasons for referral were the expected difficulty of the operation, the medical condition of the patient and the lack of facilities for general anaesthesia. Most referrals were made to the oral and maxillofacial surgery department of a general hospital but almost three-quarters of the respondents stated that they would refer patients to specialist surgical dentistry practices in the future. Few referrals to a university department of oral and maxillofacial surgery were considered to be inappropriate, nor were requests for a particular type of anaesthesia. Any future transfer from secondary to primary care for oral surgery may be hindered by the reduction in facilities for general anaesthesia in the primary care setting.

Adult↗

PubMed2000

Therapeutic manipulation of the temporomandibular joint.

UNLABELLED: We present a prospective study of manipulation of the temporomandibular joint (TMJ) under a general anaesthetic undertaken to find out the success rate in an effort to reduce the number of patients referred for invasive surgery. RESULTS: Of the 55 patients invited to participate in this study, 15 improved, 15 did not, 6 showed partial improvement, and 19 were not treated. The median pre-treatment opening was 20mm (range 13-27). Among those who improved after manipulation, the median opening after treatment was 38mm (range 35-56). Some of those who improved experienced a return of TMJ clicking but not of joint or muscle tenderness. CONCLUSION: Manipulation under general anaesthesia helps some patients with disc displacement without reduction.

Adolescent↗

PubMed2000

Treatment of postoperative pain in oral and maxillofacial surgery.

We questioned 75 patients after inpatient oral and maxillofacial operations to find out how satisfied they were with the extent to which their pain had been controlled. Seventy (93%) had had postoperative pain. In 33 (47%), it was moderate and in 24 (34%), severe. Analgesic drugs were not given immediately to 6 of the 24 patients who requested them. Seventeen (24%) reported that the pain was worse than they had expected, but 74 of the 75 patients were satisfied with the pain control they received. We conclude that patients' expectations of pain control are low and that questions about satisfaction should not be used in isolation.

Acetaminophen↗

PubMed2000

Removal of porcelain veneers aided by a fluorescing luting cement.

PURPOSE: Porcelain veneers are a safe and effective treatment modality for selected teeth that have poor esthetics. However, removal of porcelain veneers that have failed may be time-consuming and involve considerable removal of sound tooth structure adjacent to the veneer. The aim of this study was to evaluate a novel method of porcelain laminate veneer removal by incorporating a fluorescent dye into the luting cement that allows the practitioner to visualize the cement on the tooth and remove the veneer without causing residual damage to the adjacent tooth substance. MATERIALS AND METHODS: Porcelain veneers were luted on extracted teeth with a luting cement modified with a fluorescing agent. Faculty teaching staff and final year dental undergraduates were asked to remove the veneers with the aid of a curing light to render the luting cement visible by fluorescing. They were then asked to compare the removal of comparable veneers without this visual aid and to complete a standard questionnaire. The depth of cure of the conventional and modified cements was measured using a penetrometer. RESULTS: Results of the questionnaire indicated that the operators found removing the veneer cemented with the modified (fluorescing) cement considerably easier than removing the veneer cemented with the conventional cement. Microscopy indicated that more damage was caused to the underlying tooth during removal of conventionally cemented veneers. The incorporation of the dye into the cement reduced the depth of cure from 4.238 mm (SD = 0.025) to 3.761 mm (SD = 0.096).

Dental Debonding↗

PubMed2000

An evaluation of powder-free gloves in general dental practice.

PURPOSE OF STUDY: To evaluate the suitability of two non-sterile, powder-free gloves for routine use in general dental practice. BASIC PROCEDURES: Randomly allocated blind evaluation of two powder-free gloves by five dentists and five dental nurses in general dental practice. Each dentist and dental nurse were allocated a four-day supply of two unnamed powder-free gloves. Following glove usage a questionnaire sought their views regarding ease of donning, operator comfort, puncture and tear resistance, and tactile sensitivity. Details of procedure undertaken, time of wear and puncture and tear formation for the dentists' gloves were also recorded. The dentists' gloves were retained and subsequently tested for punctures and tears. MAIN FINDINGS: In terms of ease of donning, operator discomfort, tear resistance and tactile sensitivity neither glove was ideal, however one glove was rated higher than the other. Overall, the dentists noticed only half of the punctures and tears detected in the laboratory. One glove was more prone to punctures with the other glove more liable to tear. Time worn in excess of 20 minutes and endodontic procedures were associated with a higher incidence of punctures. PRINCIPAL CONCLUSIONS: The two powder-free gloves evaluated in this study would appear not to be suitable for routine use in general dental practice. Further developments are required before powder-free gloves of the type evaluated can be expected to receive widespread acceptance for routine use by dentists and dental nurses in general dental practice.

Chi-Square Distribution↗

PubMed1999

Relating personality to interview results and performance in the first year of the dental course.

The aim of this paper is to relate personality measures of Year 1 undergraduate dental students to their performance at admissions interview and during the first year of their course. The personality profiles of 58 first year dental students, were statistically related to results of the first year examinations and to the results of 54 of the students' structured admissions interviews. A relationship was found to exist which related personality to interview results and performance in the first year of their dental course.

Achievement↗

PubMed1999

An analysis of an admissions system: can performance in the first year of the dental course be predicted?

The admissions process must be scrupulously fair and select the most suitable students. Data on applicants to the Manchester Dental School for the 1996/97 academic year were analysed. The aims of this project were to: describe the applicants using information from the UCAS (university entrance) form; to relate information from the UCAS form to interview performance and A-level results; and to evaluate whether these factors can predict performance during the first year of the course.

Achievement↗

PubMed1999

Influence of patient age on the nature of tooth fracture.

STATEMENT OF PROBLEM: There is much controversy in the literature relating the incidence of tooth fracture to patient age. The nature (complete or incomplete) of fracture is one aspect that is frequently reported; however, the results highlight relative differences with respect to age and the inadequacy of the statistic used for analysis. PURPOSE: This study: (1) reviewed the existing literature on the relationship of patient age and nature of tooth fracture, (2) investigated the nature of tooth fractures among attendees of an emergency clinic, and (3) assessed any relationship between nature of fracture and patient age. MATERIAL AND METHOD: From the existing literature, 6 studies were suitable for combined analysis. The study was conducted among subjects attending the Student Emergency Dental Service in the University Dental Hospital of Manchester over a 2-year period, 1995-97. Each study subject had a fractured tooth and was examined by 1 of the authors and data were recorded. RESULTS: Combined analysis showed that the age of patients with incomplete fractures was higher than those with complete fractures (P <.05). A total of 229 patients exhibited complete (n = 263) or incomplete (n = 8) fractures of 271 teeth. Age range of 18 to 47 years demonstrated a skewed distribution with a median of 21 years. There was a statistically significant difference in age distribution between the 2 natures of tooth fracture (P <.05) with incomplete fractures associated with older ages. CONCLUSION: Incomplete tooth fractures are uncommon in students attending an emergency clinic. Complete fractures may occur at any age, while it appears that incomplete fractures are associated with older age groups.

Adolescent↗

PubMed1999

Organising the introduction of, and evaluating interviewing in, an admissions system.

This paper describes the admissions process, especially the organisation of an interviewing system. The method of application to Dental School is discussed and basic selection processes outlined. The introduction of a new interviewing system is explained and criteria for interview selection and marking defined. All interviewers received regular training; the content of training days is described together with the experience of those involved. Changes made to the interview marking system after 1 year are discussed. Criteria marked at interview were monitored against students' success in year 1 and 2 examinations. Results show that students who performed highly at interview for leadership were more likely to succeed in semester 2 of the course and in year 1 examinations overall.

Communication↗

PubMed1999

Perceived sources of stress in dental students.

A 36-item questionnaire was used to investigate the stress perceived by students at Manchester Dental School to potential stressors, grouped under the headings of living accommodation, personal factors, educational environment, academic work and clinical factors. The stressors producing the highest ratings for perceived stress varied throughout the course but high values were allocated to examinations, fear of failing the course or year, shorter and fewer holidays than other university students and--for clinical students--approachability of staff and completing the required quantity and variety of work within a limited time. Female students experienced greater stress than their male counterparts. Since high levels of perceived stress can reduce student performance, dental schools should consider courses in stress management.

Adult↗

PubMed1999

Some aspects of data analysis in dentistry.

In dentistry many studies collect hierarchical data, but this is not always recognised or understood by the researchers. This paper sets out to describe such studies and discusses aspects of their design, data collection and analysis. Sometimes these studies may be dealt with in a simple way, but others may require the help of a professional statistician to deal with analytical problems that are encountered.

Data Interpretation, Statistical↗

PubMed1996

The influence of alcohol consumption on worldwide trends in mortality from upper aerodigestive tract cancers in men.

STUDY OBJECTIVES: To assess current trends in male mortality from cancers of the oral cavity/pharynx, oesophagus, and larynx (upper aerodigestive tract cancers), and relate these to past national consumption of alcohol and smoking of cigarettes. To assess the impact of current trends in alcohol consumption and tobacco smoking on likely future rates of these cancers. DESIGN: Mortality data for cancers of the oral cavity/pharynx, oesophagus, and larynx were obtained for the years 1955-89 in 25 countries located in North America, Australasia, Europe, and Japan. Information on past and current alcohol consumption was also obtained for these countries, while current national lung cancer rates were used as a proxy measure of past smoking levels. SETTING: The World Health Organization mortality database. MAIN RESULTS: National death rates from cancers of the oral cavity/pharynx, oesophagus, and larynx (considered together) are currently increasing among men and are most strongly associated with the level of per capita consumption of alcohol 20 years previously. They were less strongly associated with the level of alcohol consumption 10 years ago, and only very weakly associated with the current level of lung cancer mortality (a marker of past smoking habits). Regression analysis showed that the national rate of upper aerodigestive tract cancer could be estimated using information on past alcohol consumption and an interaction term between alcohol consumption and current lung cancer rates. Assuming stability in rates of lung cancer, the sizeable increase in alcohol consumption from 5 to 10 litres per capita each year that occurred in some countries during the 1960s and 70s means that increases of around 5 per 100,000 in the death rate from these cancers can be expected in these countries in the next decades. CONCLUSIONS: Previous alcohol consumption in a country is a strong predictor of deaths from cancers of the upper aerodigestive tract in men, and current increases in death rates can probably be related to increases in consumption which took place during the 1960s and 70s. Combined with a reduction in tobacco smoking, which is already taking place in some countries, reversing the trend of increases in consumption of alcohol has the potential for a sizeable impact on the burden of these cancers.

Alcohol Drinking↗