Co-ordinated treatment of secondary cleft deformities

Secondary cleft deformities result from the cumulative effects of functional and morphological abnormalities. Treatment choices should be based on a comprehensive plan which is designed to minimize treatment time and iatrogenic effects and which is based on sound physical and psychosocial objectives. Conventional orthodontic and orthognathic surgical principles can be modified and applied to a variety of facial cleft problems. Direct surgical correction of secondary deformities instead of prosthetic or orthodontic compensation expands treatment possibilities and optimizes treatment results.     

A study of the viscosity of saliva at different shear rates in dentate and edentulous patients

A Wells-Brookfield microviscometer was used to measure the viscosity of saliva from dentate and edentulous individuals at shear rates ranging from 1·15/s to 230/s. The advantages of using such an instrument are discussed in the light of the recognition of saliva as a viscoelastic fluid exhibiting non-Newtonian viscosity. The viscosity of saliva of the dentate group was found to be significantly higher than that of the edentulous group at shear rates above 1l·5/s. It is suggested that these differences may be related to the mucin content of saliva.     

Do self-curing acrylic resin repairs gain strength with age?

The effect of age on the strength of self-curing acrylic resin repairs has been investigated. Several other properties which may be related were also studied. The findings indicate that the strength of a repair increases with time, attaining a significant proportion of its final strength by 24 hours and reaching a maximum between 1 day and 1 week.     

Exfoliative cytology in clinical oral pathology

Exfoliative cytology is a rapid, non-invasive procedure for assessing dysplastic change within the oral epithelium. The indications for oral exfoliative cytology are reviewed and a technique for cell collection and smear examination is presented. The value of exfoliative cytology in oral cancer screening programmes as a public health measure is discussed.     

Differences in the perceptions of HIV risk amongst dental care providers in Western Australian clinics

This paper examines the perceived risk of occupationally contracting HIV among dental care providers. This examination is based upon responses to a mailed questionnaire from all registered dentists (76 per cent response rate, n = 550) and dental therapists (63 per cent response rate, n = 208) in Western Australia during 1992. Results indicate that: 1) dental care providers who perceive a high risk of occupationally contracting HIV report a more conservative, cautious approach to HIV infection than do providers who perceive less risk of contracting the virus; 2) dental therapists are more likely than dentists to report a higher degree of perceived risk of occupationally contracting HIV; and 3) dentists are more likely than dental therapists to perceive compliance with universal precaution guidelines in dental practices in which they work. Reasons are presented for a suspicion that both sets of perceptions may be exaggerated. The need to educate dental therapists on the realistic risks of occupationally contracting HIV and to educate dentists on the value of compliance (and of appearing to comply) with universal precaution guidelines in order to help reduce undue stress and hindrances in the provision of safe and effective dental care in this era of AIDS concludes this paper.     

Langerhans cell disease associated with pathological fracture of the mandible

A 27-year-old male suffered a fractured mandible following extraction of a tooth. It was subsequently found that the fracture occurred in an area pathologically weakened by a localized lesion of Langerhans cell disease. Since lesions of the jaws may be seen either as the first manifestation or as a complication of widespread Langerhans cell disease, the dentist has a major role in the diagnosis and management of such cases.     

Porosity in composite resins—an Achilles' heel?

An investigation of the porosity present in a wide range of composite resin dental restorative materials has shown mean levels of 2·0–3·3 per cent by volume in the cured restoration when using the two-paste systems. Most single-paste light-activated materials showed a mean porosity of less than 0·8 per cent by volume. The relationships between porosity and some clinical and physical properties of the resultant restoration are discussed.     

Post-orthodontic occlusal function

The significance of orthodontic treatment in the aetiology of temporomandibular dysfunction continues to be a matter of controversy. However, the evidence of any association has been generally negative. This investigation involved the examination of a study group of 87 post-orthodontic patients, the average time out of all retention being 52 months. They were compared with an untreated control group. Signs and symptoms of temporomandibular disfunction were assessed for both groups. In only one instance, soft joint click, was there found to be a significant association between the treatment category and the occurrence of the symptom, there being a higher rate of soft clicks in the post-treatment group. While this may be ascribed to orthodontic treatment, there was also a different restorative pattern in the two groups. No other significant associations were found.     

Methodological Considerations in the Analysis of Cost Effectiveness in Dentistry

Cost-effectiveness analysis is a technique applied with increasing frequency to help make rational decisions in health care resource allocation. This article reviews the ten general principles of cost-effectiveness analysis outlined by the Office of Technology Assessment of the US Congress and describes a model for such analyses used widely in medicine, but only recently applied in dentistry. The imperative for the formulation of the best current information on both the effectiveness of dental practices and their costs is made more urgent because of the now universally recognized belief that resources available to meet the demands for health care are limited. Today's environment requires critical allocation decisions within categorical health problems, across diseases, or relative to other health problems. If important health benefits or cost savings are to be realized, then these analytic approaches must become widely understood, accepted, and appropriately applied by key decision makers in the dental health sector.     

The design and construction of dental elevators

Three new elevators for use in dentoalveolar surgery have been designed and tested. Their mechanical efficiency was examined experimentally, and clinical trials have been completed. Used in appropriate circumstances, these elevators approach the ‘ideal’ for safe effective exodontia.