Labial adenocarcinoma after treatment with cyclosporin a in a patient with panuveitis.

PURPOSE: To report a case of labial basal cell adenocarcinoma in a patient with uveitis on treatment with cyclosporin A. METHOD: Case report. A 73-year-old woman with panuveitis and retinal vasculitis presented with a lump on her lip after 52 months of treatment with cyclosporin A. RESULT: Excision biopsy showed a labial adenocarcinoma. CONCLUSION: Malignancy can occur after long-term cyclosporin A treatment for uveitis.

A comparison of manual and automatic processing in general dental practice.

Although automatic processing is becoming more widely available in general dental practice, there is little objective information regarding the quality of this type of processing. Thus a postal study was undertaken to compare manual and automatic processing using a questionnaire together with a standardised, pre-exposed test radiograph for routine processing. Analysis of variance showed significant differences between the manually processed, automatically processed and control test films, in respect of D Min (P < 0.001), test strip (P < 0.001), and step density values (P < 0.01) but not for D Max (P > 0.1). The manually processed test films generally had significantly less density than the automatically processed test films or control test films.

Canalicular adenoma of the palatal mucosa.

The clinical and histological features of a canalicular adenoma occurring in the palatal mucosa of a 79-year-old male are described. The management of the case-prompt referral to a specialist centre, histological confirmation of complete excision and an uneventful postoperative course-illustrates the correct procedures for what may be regarded as a cure of this neoplastic disease.

How important is tumour shape? Quantification of the epithelial-connective tissue interface in oral lesions using local connected fractal dimension analysis.

Quantification of the local complexity of the epithelial-connective tissue interface (ECTI) in normal mucosa, epithelial dysplasia, and squamous cell carcinoma of the floor of the mouth was investigated by estimating the local connected fractal dimension in tissue profiles from histological sections. The use of certain parameters of the distribution of the local connected fractal dimensions of the ECTI classifies the cases belonging to these three histopathological diagnoses with 85 per cent accuracy by means of linear discriminant analysis. The values of the local fractal dimension were also used to produce colour-coded dimensional images of the ECTI, to highlight locations with higher irregularity that may correlate with locally invasive 'higher-risk' areas.

Quantification of nuclear pleomorphism using an asymptotic fractal model.

OBJECTIVE: Nuclear pleomorphism (nuclear membrane irregularity) was investigated using transmission electron microscope (TEM) micrographs of 1,419 nuclei (32 oral carcinomas and normal cells from surgical margins). STUDY DESIGN: Nuclear profiles (1,400 x) were digitized (1 pixel = 35 nm) and fractal dimension estimated using the "yardstick" method. RESULTS: Log-log plots of yardstick length vs. perimeter showed a significant effect on length measurement typical of fractals at low resolutions (large yardsticks), but this effect disappeared at higher resolution (small yardsticks); that is compatible with Rigaut's asymptotic fractal model. Analysis of the asymptotic fractal parameters c, L and Bm showed that c was higher in normal nuclei, but log(L) and Bm were higher in malignant nuclei. A linear discriminant analysis using c, log(L) and Bm reclassified correctly 78.8% of the nuclei (normal 88.0%, tumor 70.2%). CONCLUSION: Asymptotic fractal analysis of nuclear profiles appears to show great potential for quantitative discrimination of oral cancer cell features.

The distribution and severity of tooth wear and the relationship between erosion and dietary constituents in a group of children.

There is very little published information on the severity of tooth wear in children. The current investigation involved clinical examination of 101 children and an assessment of their dietary habits. Evidence of tooth wear was found in over 80% of maxillary incisor teeth, and 30% of primary molar teeth had some dentine exposed. There were 21 children who were regarded as having 'mild' erosion, 45 'moderate' erosion and 35 'severe' erosion. There were highly statistically significant differences between the three groups in relation to drinking habits; the mean number of carbonated drinks consumed per week by children in the 'mild', 'moderate' and 'severe' erosion groups was 3.9, 5.8 and 13.9 respectively, of fruit drinks 10.3, 16.4 and 18.3, and of all fruit-based drinks 17.9, 27.1 and 39.0. There were also highly significant differences in those having a fruit-based drink at bed-time; 14% in the 'mild' erosion group, 32% in the 'moderate' and 60% in the 'severe' group. Although fresh fruit and yoghurt consumption followed the same trend, this did not reveal statistically significant differences. It is important to identify children who exhibit clinical evidence of erosion so that advice can be given about consumption of acidic dietary constituents.

Case report: squamous odontogenic tumor of the gingiva.

Gingival swellings are common and most often associated with infection. A case due to the rare peripheral squamous odontogenic tumor is described. It is considered premature to regard peripheral odontogenic tumors as either hamartomatous or neoplastic, and close follow-up of all such lesions is necessary.

Notes on the implementation of the mass-radius method of fractal dimension estimation.

The graphical implementation in computers and image analysers of the mass-radius method of fractal dimension estimation has two sources of error. The first is associated with underestimation of area of the 'circle scan' in a square matrix; the second arises from the overestimation of areas at small radii. Methods of coping with these problems are described.

Cleaning of oval canals using ultrasonic or sonic instrumentation.

This study investigated the effect of direction of file oscillation on the amount of debris and smear remaining within oval canals. Sixty-five lower premolars were allocated to six experimental groups (n = 10) and one control group (n = 5). Canals were prepared using Gates Glidden burs and hand instruments. Preparations were completed using either an ultrasonic size 15 K file or a sonic size 15 shaper file. Three preparation techniques were used: (a) file oscillation toward oval recesses within the canal, (b) file oscillation at right angles to the recesses, and (c) rotational movement of handpiece. Canals were examined under the scanning electron microscope and blindly scored for debris and smear layer. Log linear analysis revealed no significant difference (p > 0.05) between sonic or ultrasonic instrumentation as to debris or smear layer remaining. File oscillation directed toward oval recesses left the least amount of debris (p < 0.05). Smear layer remained unaffected by all techniques.

Fractal dimensions of the epithelial-connective tissue interfaces in premalignant and malignant epithelial lesions of the floor of the mouth.

Irregularity of the shape of epithelial-connective tissue interfaces is a well-recognized feature of malignant and premalignant epithelial lesions, yet few attempts have been made to assess it objectively. The fractal dimension (as a measure of irregularity of shape) of the epithelial-connective tissue interface of premalignant, malignant and normal epithelial tissues of the floor of the mouth was measured using box counting and boundary trace methods. The lowest value found was 0.99 (a normal mucosa using the box method) and the highest 1.61 (a carcinoma using the trace method). Analysis of the values against the histopathologic diagnoses (normal, keratosis with mild dysplasia, keratosis with moderate/severe dysplasia and squamous cell carcinoma) showed no significant difference between normal epithelium and that from keratosis with mild dysplasia, but these were significantly different from the two other diagnoses, which were significantly different from each other. The study illustrated the potential of fractal analysis for providing objective diagnostic information about irregular shapes in histopathology.

Effect of precurving endosonic files on the amount of debris and smear layer remaining in curved root canals.

Endosonic files are prone to constraint; this reduces their efficiency, particularly in the apical third and in curved root canals. Precurving the file may reduce constraint, thereby improving the file's ability to debride. This investigation was undertaken to compare both straight and precurved endosonic files as to debris and smear layer removal. Thirty-six curved root canals were randomly allocated into six groups. Each group was prepared using a step-down technique, then instrumented with either a straight or precurved endosonic file of size 15, 20, or 25. The tooth roots were split and examined under the scanning electron microscope. Blind examinations were made for debris and smear layer removal and evaluation scores were analyzed using a log linear approach. The root canals instrumented with the precurved files had a significantly lower debris score than those prepared with straight files. Precurving did not affect smear layer removal. In conclusion, precurving of files decreased the amount of debris but did not affect smear layer removal.

Intra-oral salivary gland tumours in the West Midlands.

Intra-oral salivary gland tumours reported from the West Midlands over the years 1975-88 were examined as to a number of epidemiological variables; the question as to their increasing incidence was also addressed. The findings were largely in agreement with those of most previous authors in that most of the tumours occurred in the palate, but whereas most of these were benign, a large proportion of those in other sites were malignant. However, firm conclusions are difficult to draw since there is much disagreement over reporting criteria. An international workshop and comprehensive tumour registries are required in order to determine more accurate data and conclusions. Similar cooperation is necessary in order to substantiate or refute the suggestion that the incidence of salivary gland tumours is increasing.

Odontogenic keratocyst in an infant.

Odontogenic keratocysts occur as solitary lesions or in association with the basal cell naevus syndrome (BCNS), and have been documented in the age range 5 to 83 years. A rare case of an odontogenic keratocyst in a one-year-old girl is presented. Its characteristic tendency to recur, and its association with BCNS present important clinical implications.

A study of the relationship among pulpal response, microbial microleakage, and particle heterogeneity in a glass-ionomer-base material.

This investigation was designed to study the pulpal responses to glass-ionomer base materials that differ in particle size distribution. The study was carried out according to the BSI (1980) recommendations for testing restorative materials in vivo. The base materials caused more pulpal inflammation than the control material, Kalzinol, although by an indirect mechanism. A significant association was demonstrated in the statistical model between bacterial presence within the experimental cavity and pulpal inflammation. The type of restorative material has no direct association with the degree of inflammation, although the model suggests that it exerts an indirect influence via its antibacterial properties, and hence its influence on microbial microleakage. The base material, with a heterogeneous particle distribution, was associated with greater bacterial microleakage. Particle size distribution, therefore, has some effect upon bacterial microleakage, but, because of its complex effect upon several physical properties of materials, further studies are indicated.

Pulpal response to two semihydrous glass ionomer luting cements.

This study compared the pulpal responses to two innovative semihydrous glass ionomer luting cements (STA and ZIN) with those previously obtained for a conventional anhydrous glass ionomer luting cement, Aquacem. ZIN contained zinc oxide in the formulation. The study was conducted according to the BSI (1989) recommendations for testing restorative materials in vivo. ZIN was associated with minimal pulpal changes and microbial microleakage, and differed little from the control material, Kalzinol. The pulpal response to STA was similar to that observed for Aquacem, but was associated with less microbial microleakage. The statistical model demonstrated a significant association between bacterial presence within the experimental cavity and pulpal inflammation. The closer that bacteria were to the pulp, the more severe was the ensuing inflammation.

Bilateral intra-osseous neurofibromata of the mandible.

A case of bilateral neurofibromata associated with the crowns of impacted third mandibular molars in a patient with known neurofibromatosis is reported.

Pulpal response to an anhydrous glass ionomer luting cement.

This investigation was designed to study the pulpal responses to Aquacem, an anhydrous glass ionomer luting cement, and to compare the results with those previously obtained for a conventional glass ionomer luting cement, Chembond. The study was carried out according to the BSI (1980) recommendations for testing restorative materials in vivo. Aquacem caused more pulpal inflammation than the control material, Kalzinol, though by an indirect mechanism. The statistical model demonstrated a significant association between bacterial presence within the experimental cavity and pulpal inflammation. The type of restorative material has no direct association with the degree of inflammation, but the model suggests that it exerts an indirect influence via its antibacterial properties and hence its influence on microbial microleakage.

Analysis of cell cycle subpopulations from cytometric data.

As a result of experimental error, measurements of the DNA content of cells from proliferating populations give rise to histograms in which the G1-phase, S-phase and G2-phase distributions overlap. A new method for distinguishing these subpopulations is proposed, based on a model in which the S-phase subpopulation is made up of a number of uniformly overlapping log-normal curves, whose composite has a rectangular central part and sloping ends. The ratio between certain parameters of the slopes and the height of the rectangle is shown to be closely related to the degree of overlap of the constituents by a defined cubic polynomial. It is then possible to calculate the numbers of cells in each of the three phases of the cell cycle, even when only a few hundred cells have been measured.