An investigation of the rationality of lower third molar removal, based on USA National Institutes of Health criteria

The appropriateness of surgical removal of lower third molars was audited in relation to 500 consecutive patients referred to hospital for third molar management during 1993/4. The National Institutes of Health (NIH) criteria were used as the validating standard. Immediately after patients had been seen for treatment planning, research workers repeated history taking and clinical examination and recorded the treatment that was planned. Appropriateness of treatment planning was then assessed. A total of 95% of patients had bilateral and 5% had unilateral lower third molars (976 teeth in all); 69% were partially erupted, 35% unerupted and 5% fully erupted. There was a weak correlation between eruption status of bilateral third molars. The most frequent reason for removal of third molars (31%) was pericoronitis, though the next most frequent reason was that the contralateral tooth had been scheduled for removal under general anaesthesia. Allowing this as a legitimate reason for surgery, of 859 teeth scheduled for removal, 59% were justified according to NIH criteria. Some 169 (34%) of patients might have avoided surgery altogether if NIH criteria had been the basis for intervention and a further 147 (30%) could have been scheduled for removal of only one lower third molar. These findings suggest that criteria for removal other than NIH criteria are being applied. Further research is necessary to identify these.

An investigation of the interaction between alcohol and fibroblasts in wound healing

This study investigated the effect of clinical concentrations of alcohol on fibroblast function (proliferation and ECM synthesis) in vitro. Basal and TGF-beta-induced collagen synthesis was assayed in confluent cultures in serum-free medium at 48 h with a commercial collagen assay system. At concentrations of alcohol > 5%, fibroblast proliferation was significantly inhibited. Although noninhibitory, subclinical concentrations of alcohol failed to inhibit basal collagen synthesis (P > 0.1), they significantly decreased TGF-beta-induced collagen synthesis (P < 0.03). These data support the notion that the local, as well as the systemic, effects of alcohol are important in mediating delayed healing in alcoholic patients.

Performance of a neural network trained to make third-molar treatment-planning decisions

The authors developed and tested 12 neural networks of different architectures to make lower-third-molar treatment-planning decisions, using a software-based neural network (Neudesk 1.2, Neural Computer Sciences, Southampton, UK). Network training was undertaken using clinical histories from 119 patients (with 238 lower third molars) referred for treatment planning (79 females and 40 males, mean age 25 years) together with output data consisting of actual treatments planned by a senior oral surgeon. Both the input clinical data and the consultant decisions were treated on a tooth-wise basis and were coded to numerical values. Binary data (e.g., present/absent) were coded to 1 and 0, while quantitative data (e.g., age) were scaled to fall between 0 and 1. A network based on the optimal architecture was trained and then interrogated with test data derived from a further 174 patients (119 females and 55 males, mean age 26 years) with 348 lower third molars. Network decisions were dichotomized with a threshold of 0.8. With no knowledge of the network decisions, the senior oral surgeon indicated his preferred treatments. The teeth were then assigned to "gold-standard" categories of indications present or absent based on National Institutes of Health consensus criteria. Against this, the network achieved a sensitivity of 0.78, which was slightly inferior to that of the oral surgeon (0.88), although this difference was not significant, and a specificity of 0.98, compared with 0.99 for the oral surgeon (p = NS). Agreement between the oral surgeon and network decisions was very high (kappa = 0.850). This study demonstrates that it is possible to train a neural network to provide reliable decision support for lower-third-molar treatment planning.

Patient perceptions regarding the risks of morbidity and complications of lower third molar removal

The risks associated with third molar surgery are well established. Current philosophy stresses co-development of treatment plans with patients, who need to understand the complications and risks of possible treatment. This understanding was therefore investigated at an initial outpatient appointment (n = 91) after a verbal explanation and immediately prior to surgery (n = 73), by means of visual analogue scales to assess patients' perceptions of the likelihood of each outcome. Most patients (98 percent) responding at an initial appointment (t1) felt that they had been given enough information regarding reasons for removal but the proportion was lower (88 percent) for patients responding at the time of surgery (t2). This reduction was also found for information regarding post operative pain, swelling, trismus and nerve damage. Patients estimated the likelihood of pain as t1 = 70 percent, t2 = 80 percent, swelling t1 = 76 percent, t2 = 75 percent, trismus t1 = 74, t2 = 73 percent, temporary nerve damage: transient labial t1 = 46 percent, t2 = 33 percent, transient lingual t1 = 51 percent, t2 = 41 percent, and permanent nerve damage: labial t1 = 13 percent, t2 = 7 percent, lingual t1 = 14 percent, t2 = 9 percent. At t1 and t2 the mean perceived likelihood for pain, swelling and trismus were significantly higher than the known prevalence of these sequelae. The mean values for temporary lingual and labial anaesthesia were considerably higher (P < 0.05) than the reported prevalence. It was concluded that patients overestimated the likelihood of post operative complications and that these estimates varied with time. The validity of patients' estimates might be improved by verbal explanation supplemented by provision of written information.

Victim as offender in youth violence

STUDY OBJECTIVE

To determine how often adolescent and young adult victims of assaultive injury are offenders in assaults and other crimes.

DESIGN

Comparison of 10- to 24-year-old males treated in the accident and emergency department for assault-related injuries to similar-aged males treated in the same department for unintentional injuries. Police records were searched on both groups for warnings or convictions.

SETTING

Accident and emergency department of the Cardiff Royal Infirmary.

RESULTS

Assault patients were significantly more likely to be formally warned or convicted, and they had a higher mean number of warnings or convictions per 100 person-years of exposure, than other injury patients. These differences were most pronounced for the younger patients and for the year following the injury.

CONCLUSION

These results suggest that many young male assault patients either have a history of criminal activity or develop criminal behavior subsequent to their assault and may benefit from appropriate intervention aimed at interrupting the cycle of crime and violence.

The management and repair of wounds of the face

A practical guide to the causes, types, and repair of injuries of the face

A technique for the computerized identification of orthodontic instruments

Increasingly, orthodontic instruments must leave the chairside or even the clinic in order to facilitate adequate sterilization. The tray system employed in an orthodontic clinic is outlined. Inevitably, there are problems with instruments being lost from these trays and finding some method for individual 'tagging', which is also resistant to autoclaving, would be a useful facility. To address this problem a robust procedure of automatic instrument identification, similar to bar coding, has been deployed. This system, termed matrix coding, not only facilitates easy instrument identification, but also allows every episode of clinical use and sterilization to be recorded. By such a method it could become possible to quickly establish when instruments are likely to require servicing, sharpening or replacement.

The relationship between alcohol intoxication, injury severity and Glasgow Coma Score in assault patients

To assess the effect of alcohol intoxication on injury severity and head injury assessment, blood alcohol concentrations (BAC) were related to the severity of injuries (Injury Severity Score and Assault Trauma Score) and Glasgow Coma Scores (GCS) in 242 consecutive victims of weekend, night-time assault, none of whom had head injuries. No correlation was found between degree of intoxication and severity of injury. There was a highly significant correlation between BAC and GCS. However, high BACs (greater than 240 mg/100 ml) were associated with only a 2-3 point reduction in GCS. The median BAC in patients with a normal GCS was 115 mg/100 ml. Neurological assessments need to take account of the highly variable, depressive effects of alcohol.

The management of soft tissue facial wounds

The physiological and physical principles involved in the management of facial lacerations are reviewed. Because there have been no previously published descriptions of the actual problems encountered in clinical practice in A & E Departments, a prospective clinical survey of 100 consecutive patients with facial lacerations repaired by oral & maxillofacial house surgeons was undertaken and a series of lacerations was studied in detail. These included periorbital, nasal, labial and neck injuries. High magnification revealed irregularity of wound margins in almost all cases, frequent localised ischaemia, necrosis, localised dehiscence and infection or inadequate closure. Because all of these problems are likely to increase scarring and deformity, this study suggests the need for a re-appraisal of the management of facial lacerations, particularly in relation to local skin edge excision, prevention of infection, and the use of magnification during closure.

Decision analysis for lower-third-molar surgery

The objective of the study was to identify those factors that should affect treatment planning for patients who have lower third molars, using decision-analytic techniques. Utility values based on data from 104 patients indicated that the respondents considered that postoperative complications (except mild pain and temporary paresthesia) reduced health to a greater degree than did complications following non-intervention. A decision analysis indicated that the maximum expected utility of prophylactic third-molar surgery (60.25) was lower than that for non-intervention (76.96). The decision was sensitive to changes in the probabilities of occurrence of recurrent pericoronitis (threshold = 0.52), resorption of an adjacent tooth (threshold = 0.29), loss of an adjacent tooth (threshold = 0.32), and cystic change (threshold = 0.34). These thresholds are much higher than the incidence of problems affecting the lower third molar shown by a concurrent clinical audit and literature review. This study therefore suggests that lower third molars should not be removed prophylactically.

Healthy decision making: a new approach in health promotion using health state utilities

Empowerment of the individual is the central tenet of health promotion philosophy. Application of health state utility methodology to clinical decisions will facilitate this process. The study reported here used health state utilities to examine the preferences of young adults concerning third molar care. Respondents were asked to indicate the strength of their preferences for various outcomes consequent to removing, or not removing these teeth by using standardised visual analogue scales. The results demonstrated that health state utilities for most complications of surgery were lower than, and therefore reduced health more than, those associated with the complications of leaving teeth in place. Therefore dental surgeons should be more circumspect about surgical intervention: this group of potential patients believed that the 'cure' is often worse than the 'disease'. This study illustrates the use of health state utilities, a methodology which allows patients' perspectives to be incorporated into the planning of rational health care.

A new method of assessment of clinical teaching: ROC analysis

Twenty-five clinical dental students with varying clinical experience were presented with case records consisting of a clinical history and a panoramic radiograph for 25 patients with bilateral lower third molars ('wisdom teeth'). The students were asked to indicate how certain they were that each lower third molar tooth needed removal using a 6-point rating scale. Immediately following the task, the students were presented with information on the indications for removal of lower third molars in the form of a lecture by a senior academic clinical teacher. One week later the students were asked to repeat the rating study, under the same conditions as before, using a further 25 clinical cases. Receiver operating characteristics (ROC) analysis, which provides a graphical and quantitative assessment of a group of observers' ability to detect need for treatment, was utilized to examine differences between junior and senior students and between the matched pre-training and post-training experiments. The ability of junior students to assign lower third molars for surgery was statistically no better than random selection of cases. Formal clinical teaching significantly improved this group's performance, but had no effect on the performance of senior students. Senior students were significantly better able correctly to assign lower third molars for surgical intervention than junior students. Therefore this study shows that clinical experience has a significantly greater influence on treatment-planning ability than formal teaching. ROC analysis is a useful tool for assessing the effectiveness of methods of undergraduate training.

Characteristic illness behaviour in assault patients: DATES syndrome

Violent crime has become a public health issue, not least because the needs of victims have been neglected in the criminal justice system. Since this group suffer more psychological distress than victims of accidents, we compared illness experience in 433 adult assault victims with paired victims of accidents in a case control study. In the 10 year period prior to injury, there was a significant excess of hospital contacts in the assault group in relation to trauma, elective surgery and drug abuse but not to other psychiatric or medical conditions. This spectrum of disorders constitutes a previously unrecognized syndrome in young adults, probably representing the manifestations of antisocial personality.

Helicobacter pylori infection in dentists--a case-control study

To test the null hypothesis that frequent and multiple salivary exposure is not a risk factor for developing H. pylori infection, serum anti-H. pylori IgG from 179 dentists and dental students and 179 age-, sex- and socioeconomic-matched controls were assayed using an ELISA. Seroprevalence in dentists was 16% (11/70); clinical dental students 6% (3/47); and pre-clinical dental students 10% (6/62). There were no differences in H. pylori seropositivity between cases and controls. There was an increase in H. pylori seropositivity with age (chi (trend)2 9.04, p = 0.003). These data provide evidence that adults are not at high risk of developing H. pylori infection as a result of exposures to saliva from multiple sources.

The pathogenesis of hypertrophic/keloid scarring

The formation of hypertrophic and keloid scars after cutaneous wounding is of particular relevance to the practice of maxillofacial surgery. This paper reviews current knowledge of the local and systemic factors underlying the formation of these scars and outlines the current and potential treatment modalities for these lesions.

Mandibular deformity associated with Paget's disease. Case report

Paget's disease (osteitis deformans) and osteoporosis represent the commonest systemic bone disorders. Clinically Paget's disease may be mono-, or polyostotic, and is characterized by excessive and disorganized formation and resorption of bone. It may affect any of the facial bones, most notably the skull and the jaws. A case is described in which the only symptomatic manifestation of Paget's disease was mandibular prognathism. The pathogenesis, aetiology, and management are discussed.

Risk of occupational glass injury in bar staff

One hundred and twenty-six bar staff (median length of service 2.7 years) working in 42 randomly selected public houses in South Glamorgan were interviewed and examined in the workplace to investigate the incidence, characteristics and treatment of lacerations from bar glassware. 41 per cent reported previous injury, 13 per cent on five or more separate occasions. All injuries but one were of the hand. After 13 per cent of incidents, treatment had been sought in an A & E department, but 58 per cent of incidents causing hand lacerations were not treated. Straight-sided (nonik) one pint (0.6 l) capacity glasses were responsible for two-thirds of injuries, usually during stacking and washing of used glasses. Of bar-workers familiar with toughened glassware, 86 per cent favoured its use on safety grounds. It was concluded that the incidence of sharps (glass) injury was unacceptably high and that this was also a potential cause of cross-infection in this group of workers.

Automatic identification of surgical and orthodontic instruments

Surgical instruments are becoming increasingly expensive and represent an important component of the costs of operating theatres. The use and processing of surgical instruments in decontamination and packaging units and in the operating theatre need to be monitored, both to improve efficiency and to allow measurement of the effectiveness of training in operative technique. Automatic identification of surgical and orthodontic instruments was therefore performed using two standard methods: the two-dimensional bar-code and matrix code. Encryption (the formulation of codes), was carried out prior to bar and matrix coding using acid-etch and laser techniques respectively. 'Reading' of the two types of code was more difficult with bar-codes because of the high reflectivity of background polished stainless steel, and only large instruments had sufficient area for bar-coding. Consistent, accurate, automatic identification of the instruments was possible with the matrix code for which a surface of only 4 sq mm is necessary. After 50 cycles of decontamination and packaging, neither code showed obvious deterioration and it was possible to read the matrix code as easily as prior to this process. Automatic instrument identification is possible using recently developed methods and could facilitate economies in the processing of instruments in health facilities and the automatic recording of instrument usage in the operating theatre.

The measurement of injury severity

Severity of injury can now be measured objectively and in a manner relevant to everyday practice. A variety of scales/scores are available which are based either on anatomical or physiological parameters or a combination of these. ASCOT methodology represents the most recent major contribution in this area, and follows AIS and TRISS as an established and reliable means of assessing trauma patients, particularly in relation to survival. These methods have clinical application in terms of triage, directing clinical management, assessing prognosis, assessing cost of management and for measuring outcome. The development of these scoring methods is outlined in this paper.

Paget's disease of bone: current concepts in pathogenesis and treatment

Recent advances have been made in understanding the aetiology, diagnosis and treatment of Paget's disease of bone (osteitis deformans). The role of viruses in the pathogenesis of the disease has been extensively investigated, although no causative link has yet been demonstrated between infective agents and Paget's disease. Recent advances in the diagnosis of the disease have been made with increasing usage of radionucleotide imaging to determine the extent and distribution of the lesions. Treatment options have been extended with the emergence of the biphosphonates as potential main line therapeutic agents.