Transmission illumination of teeth. A system for operative dentistry procedures

In an in vitro trial, transillumination provided good, comfortable vision of an operating area both during cavity preparation and the insertion of adhesive restorative materials. Secondly, transillumination provided better differentiation of hard tissues and their condition than incident illumination; this was particularly noticeable in deciding on the presence of caries at the dentino-enamel junction. The most suitable colour was in the green range of the spectrum and a variable intensity control was desirable. With refinement, this system could facilitate operative dentistry particularly for difficult situations.     

Image enhancement of the mandibular condyle through digital subtraction

The use of conventional radiography to visualize the mandibular condylar articulating surface is limited by the superimposition of surrounding bony elements, which can be termed structured noise. This study investigated the application of digital subtraction to reduce such noise. Two conventional radiographs were made of a temporomandibular joint: first a reference radiograph with the condyle seated in the glenoid fossa (simulating a patient with mouth closed), then a radiograph from the identical orientation but with the condyle translated slightly downward and forward (simulating mouth partially opened). The radiographs were digitized and, on a pixel-by-pixel basis, the intensity value of the second image was subtracted from the reference image to produce a third, subtracted image. The subtracted image provided a significantly improved visualization of the condyle's superior surface.     

The effects of megadoses of ascorbic acid on PMN chemotaxis and experimental gingivitis

A double-blind study was undertaken to determine the effects of megadose ascorbic acid supplementation on plasma ascorbate levels, polymorphonuclear neutrophil (PMN) chemotaxis and clinical and biochemical determinations of inflammatory progression in individuals with a mean daily ascorbate intake level of approximately twice the recommended daily allowances. Results indicate that although the group receiving ascorbate supplementation demonstrated a significant increase in plasma levels of the vitamin as compared to a placebo group, no significant differences with respect to PMN chemotaxis or responses to experimental gingivitis were found between the groups.     

The emotional impact of orthognathic surgery and conventional orthodontics

Previous research by the authors has pointed to depressive reactions among orthognathic surgery patients during the fixation-removal stage and up to 9 months later. However, less is known about emotional shifts among persons who choose to undergo conventional orthodontic treatment after considering surgical orthodontics. In the current study, a standard measure of mood states was applied to 90 surgical patients and 66 who had considered surgery but decided against it. Of these, 33 were undergoing orthodontic treatment and 33 were having no treatment. The mood scale and measures of personality were first applied before surgery and then during orthodontic treatment, just after surgery, at fixation removal, and 6 months after surgery. Nonsurgical respondents completed questionnaires at the same time as their matched surgical respondents. Scores on tension and fatigue increased significantly among surgical patients from before surgery to immediately after surgery and dropped to presurgical levels when fixation was removed. Anger-hostility increased at fixation removal but declined within 5 months. Postsurgical discomfort, pain, and paresthesia, and interpersonal and oral function problems were correlated with postsurgery emotional state. On the later questionnaires, which corresponded to the later periods of orthodontic treatment, patients who had opted for conventional orthodontic treatment reported that they experienced greater depression, anger, and tension. These patients may be particularly vulnerable to emotional problems because their orthodontic treatment may be more complex and of longer duration than that of the typical orthodontic patient. These results point to the importance of continued psychological support for both orthodontic and surgical patients throughout their course of treatment.     

The effects of phenytoin and sodium valproate on the periodontal health of adult epileptic patients

The periodontal health of 30 adult epileptic patients treated with either sodium valproate or phenytoin was compared with a control group (n = 15) of otherwise healthy patients. The 3 groups were matched for age and sex. Patients on phenytoin therapy showed significantly higher plaque scores (P less than 0.05), gingival index (P less than 0.05) and pocketing (P less than 0.05) than patients in the control group. The % of gingival hyperplasia was significantly higher (P less than 0.05) in the phenytoin-treated patients than those on sodium valproate or in the control group. However, patients on phenytoin therapy had significantly less bone loss than those on sodium valproate (P less than 0.05) or in the control group (P less than 0.01). No significant differences were observed between the sodium valproate group and the control group on any of the parameters assessed. The results from this study would suggest that sodium valproate has no unwanted effects on periodontal health and may be considered a safe alternative, regarding the periodontal aspects, to phenytoin for the treatment of adult onset epilepsy.     

Determining approximate size of maxillary anterior artificial teeth when mandibular anterior teeth are present. Part I: Size relationship

Three methods were used to obtain a ratio of the maxillary to the mandibular anterior teeth, with results of 1.29, 1.30, and 1.31. It can be concluded that a ratio of 1.30 is sufficient to determine the approximate width of the six maxillary anterior teeth when given the size of the mandibular natural anterior teeth. This ratio should be valid to select a maxillary denture mold of sufficient width mesiodistally to obtain a Class I canine relationship. However, the ratio may need a slight adjustment to compensate for the intentional disocclusion of the maxillary denture teeth with the natural mandibular teeth. In Fig. 1 the canine to canine measurement of the mandibular anterior teeth was 35 mm; when multiplied by a factor of 1.30, a maxillary measurement of 45.5 mm is obtained. The denture teeth were to be set with approximately 1 mm of horizontal overjet and 1 mm of vertical overlap (Fig. 2), therefore a slightly larger mold of 48.5 mm was chosen (Fig. 3). This maxillary mold produced a Class I canine relationship (Fig. 4). The 48.5 mm ratio of the chosen maxillary mold to the mandibular measurement of 35 mm yielded a ratio of 1.38. When this ratio of 1.38 is applied, the desired prosthetic mold is not always available. There is a range of acceptability above and below the desired ratio.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultrastructural localization of fibronectin in duct cells of human minor salivary glands and its immunochemical detection in minor salivary gland secretion

Fibronectin (Fn) was localized in duct cells by means of a light and electron microscopic immunohistochemical technique. The subcellular localization demonstrated that Fn is synthesized in these cells and thus not exclusively produced by cells with a mesodermal background. Fn concentration, as measured by radioimmunoassay, was higher in saliva from the minor salivary glands than in unstimulated whole saliva, whereas Fn was undetectable in stimulated parotid saliva. Fn is thus a conspicuous component in unstimulated resting saliva. Fn may be an important factor, negative or positive, for the integrity of the oral hard and soft tissues because it has the capability to bind and agglutinate microorganisms.