A comparative evaluation of DIAGNOdent with visual and radiography for detection of occlusal caries: An in vitro study.

Background: The diagnosis of dental caries is fundamental to the practice of dentistry. Despite the fact that dental caries has declined considerably, it is still a problem of great importance. The reduction in caries prevalence has not occurred uniformly for all the surfaces. The greatest reduction was observed at lesions located on smooth surfaces, so that occlusal caries are most common in children. Aim: The purpose of this study is to determine the clinical efficacy of DIAGNOdent in detecting occlusal caries. Materials and Methods: A total number of 50 teeth were subjected for visual, radiographic, and DIAGNOdent examinations. All the three methods were compared to histology which is a gold standard. Results: The result obtained showed that DIAGNOdent is superior to visual and radiographic methods in diagnosing occlusal caries.

Evaluation of retinal nerve fiber layer thickness measurement following laser in situ keratomileusis using scanning laser polarimetry.

AIM: To evaluate the effect of laser-assisted in situ keratomileusis (LASIK) on the measurement of retinal nerve fiber layer thickness by scanning laser polarimetry using customized corneal compensation in myopes. MATERIALS AND METHODS: Scanning laser polarimetry was performed on 54 eyes of 54 healthy patients with myopia using the glaucoma diagnostics variable corneal compensation (GDx VCC) instrument (Laser Diagnostic Technologies, San Diego, California) before and a week after LASIK. The various parameters were compared using the Student's t test. RESULTS: No statistically significant change was observed in any of the retinal nerve fiber layer parameters before and after LASIK. CONCLUSIONS: While the measurement of retinal nerve fiber layer thickness by scanning laser polarimetry is affected by anterior segment birefringent properties and LASIK would be expected to produce changes in the same, customized corneal compensation using the GDx VCC seems to adequately compensate for these changes.

Capacidad diagnóstica de la fluorescencia láser para el diagnóstico de caries oclusal en dientes deciduos / Performance of laser fluorescence for occlusal caries diagnosis in primary teeth

Propósito: El objetivo del estudio fue evaluar in vivo la capacidad diagnóstica de la técnica de fluorescencia láser respecto a las técnicas visual y radiográfica para el diagnóstico de lesiones de caries oclusal en molares deciduos de niños entre 6 y 8 años de edad. métodos: 138 segundos molares deciduos aparentemente sanos y sin cavidad evidente fueron examinados por un observador calibrado. la mediciones fueron registradas en tres zonas de la superficie oclusal. un segundo examinador calibrado evaluo las radiografías bite wing. resultados: La prueba Z (p<0,05) mostró diferencia significativa entre las tres técnicas para las condiciones de sano y cariado. La sensibilidad de la fluorescencia láser respecto a las técnicas visual y radiográfica fue alta, mientras que la especificidad fue baja. La prueba de Mc Nemar (p<0,0001) mostró diferencia entre las técnicas. Los valores de sensibilidad y especificidad fueron de 0,92 y 0,42 para la fluorescencia con láser y 0,51 y 0,55 para la técnica visual. La fluorescencia láser sobre-registró algunas fisuras pigmentadas. La reproducibilidad intraexaminador fue buena para la fluorescencia láser (Kappa de 0,83) y baja para la técnica visual (kappa de 0,37. Conclusión: La fluorescencia láser no parece ser una técnica complementaria válida para el diagnóstico de lesiones de caries oclusal en molares deciduos. La fisura distal de los segundos molares deciduos superiores fue la zona más afectada por lesión de caries.

The normal optic nerve head on Heidelberg Retina Tomograph II.

PURPOSE: To study the characteristics of the optic nerve head using a scanning laser ophthalmoscope, the Heidelberg Retina Tomograph II (HRT II), in a normal population and to determine the specificity of HRT II diagnostic indices in the study population. METHODS: The optic nerve heads from 275 consecutive, randomly selected normal subjects were imaged on HRT II. Stereometric parameters were studied with respect to baseline variables such as age, gender, refractive error and disc size. The stereometric parameters and the results of Moorfields regression analysis (MRA) and discriminant function analysis were recorded. RESULTS: The average disc size in the population under study was 2.34 +/- 0.47 mm2. Age and gender had no significant effect on stereometric parameters. Myopic discs were larger than hypermetropic discs. MRA had a specificity varying between 85.5% and 98.2% depending upon the criteria used to define an abnormal disc. The specificity of MRA decreased with increasing disc size. The RB (R Bathija) and FSM (F S Mikelberg) discriminant functions had specificities of 96.4% and 87.3% respectively. CONCLUSIONS: Estimation of stereometric parameters of a normal disc can be used to indicate an abnormal one. Moorfields regression analysis and discriminant functions have a high specificity in our normal population; however caution must be exercised in interpreting the results for a disc area larger than 3 mm2.

Size distribution curves of blood cells in thalassemias and hemoglobin H diseases.

Thalassemias and hemoglobinopathies in Thailand have been examined with a blood cell counter based on electroimpedance principle and obtained size distribution curves of red cells and platelets. Among various disorders, beta-thalassemia/hemoglobin E and homozygous hemoglobin Constant Spring showed severe anemia. Their red cell size distribution curve shifted to the left and overlapped with the platelet size distribution curve. Red cell distribution width expressed by coefficient of variation and the degree of the overlapping were stronger in beta-thalassemia/HbE than HbH. Heterozygous beta-thalassemia showed a narrow red cell distribution curve width with small standard deviation and low England's value. Although the overlapping of size distribution curves cause inaccurate red cell count and platelet count, careful observation of the size distribution curves was proved to have high diagnostic value.

Measurements of cell volume and hemoglobin concentration of erythrocytes from hereditary ovalocytosis and hereditary spherocytosis.

Red cell analysis using the laser technique was done on erythrocytes from 11 cases of hereditary ovalocytosis (HV) and one case of hereditary spherocytosis (HS). Heterogeneity in red cell volume measured as red cell distribution width (RDW) and heterogeneity of hemoglobin concentration in the red cells as measured by hemoglobin concentration distribution width (HDW) were analyzed. All of the studied cases showed abnormal increase in both RDW and HDW. The patient with HS had decreased MCV 77.4 fL (normal range = 80-99 fL). The HS patient had microcytes 14.7 per cent with markedly increased RDW 22.3 per cent (normal range = 11.5-14.5%). Increased hemoglobin concentration was demonstrated in HS red cells as shown by increased CHCM 39.2 g/dl (normal range = 33-37) with 5.86 g/dl of HDW (normal range = 2.2-3.3 g/dl). The HV patients had slightly decreased cell volume, MCV = 84.1 +/- 11.8 fL, with 9.2 +/- 10.1 per cent microcytes and 17.5 +/- 5.7 per cent RDW. Decreased hemoglobin concentration was shown in HV red cells as shown by decreased CHCM (31.7 +/- 1.9 g/dl) with slightly increased HDW (3.3 +/- 0.9 g/dl). The HV patients had increased per cent hypochromic red cells (14.8 +/- 18.6%). The ovalocytic red cells in HV patients had obviously reduced hemoglobin concentration compared to the spherical red cells of HS patients.

Cytometric analysis of paroxysmal nocturnal hemoglobinuria erythrocytes.

Erythrocytes from six cases of paroxysmal nocturnal hemoglobinuria (PNH) were analysed by the H*1 hematology analyser using laser inspection for each individual red cell. The computer program categorized the red cells into 9 groups based on the data of red cell volume and intracellular hemoglobin concentration. The only 46.3 +/- 10.9 per cent (Mean +/- SD) of PNH red cells were normochromic normocytic. Hypochromia (hemoglobin concentration less than 28 g/dL) with normal red cell volume (between 60 to 120 fL) were found in 22.8 +/- 19.7 per cent and with large cell volume (greater than 120 fL) = 14.9 +/- 4.5 per cent of total red cells. Large cells with normal hemoglobin concentration were found in 12.9 +/- 13.2 per cent. The red cells had increased heterogeneity in red cell volume measured as red cell distribution width (RDW), Mean +/- SD = 23.6 +/- 2.3 per cent and increased heterogeneity in their hemoglobin concentration distribution with (HDW) (3.4 +/- 0.5 g/dL). The high RDW was resulted from increased number of varying size of macrocytes and the high HDW was caused by the increased number of hypochromic red cells. Heterogeneity in PNH red cell population described in this study has been postulated to relate with the clonal abnormality of the PNH red cells.