3D Computed Tomography vs. 2D radiography: comparison of 3D direct anthropometry with 2D norm calculations and analysis of differences in soft tissue measurements.

OBJECTIVE: The aim of this study was twofold: (1) to compare soft tissue measurements of the same distances obtained from 3D computed tomography reconstructions with 2D cephalometric radiograms, (2) to compare data from 3D measurements from direct anthropometry and 2D "norms" for the facial measurements. PATIENTS AND METHODS: A total of 40 Caucasian patients that had their CBCT scans for various dental and dentoskeletal reasons were enrolled in this study. All the patients had large field of view (from the forehead to the chin). The data were stored in DICOM format and imported into a software for 3D reconstructions. After 3D facial soft tissue model generation, the distances between 18 soft tissue points were measured. The 3D soft tissue analysis was performed, and the facial indices were calculated. The mean 3D values were compared with 2D measurements performed on lateral cephalograms and Arnett's and Farkas' norms. The measurements were statistically compared using Student's t-test. RESULTS: Assessments from 2D and 3D measurements showed no statistical difference except for the distance Pogonion (for both male and female) and Labial superius prominence (females) to the True Vertical Line in 2D /Plane in case of 3D measurements. There was a significant difference between all 3D measurements and Arnett's and anthropometric Farkas' "norms". The mean difference between Farkas' "norms" and 3D measurements was within 3 mm for 70% of measurements. CONCLUSIONS: According to the results, 3D soft tissue analysis allows for complete diagnostic determination. The 3D "norms" are to be verified on a greater sample.

A 3D evaluation of the upper airways and sagittal craniofacial pattern: are these two parameters associated?

Numerous studies have been published aiming to investigate the relationship between sagittal craniofacial pattern and the dimensions of upper airway, but with controversial results. The aim of the study is to verify if an association exists between a specific sagittal cranio-facial pattern and smaller dimensions of upper airway, leading so to a possible risk indicator for OSAS development. Ninety-nine cone-beam computed tomographies (CBCT) were selected from adult patients (48 males, 51 females, age range 18- 65 years). Patients were divided into 3 groups, with 33 patients each, according to their skeletal class (I: 13; III: ANB<1). The CBCT data were imported into Simplant O&O software as Dicom files. Borders for the oropharynx and for the hypopharynx of which the volumes were calculated, and the total length (L) were defined. Finally, the average cross-sectional area (a-CSA) was defined as the ratio between total volume and total length for each patient. All data were statistically analyzed using GraphPad Software. A significant difference was found between groups for oropharynx, hypopharynx, and total volume, with Class II having smaller airway dimensions. In a gender-based comparison, there was a statistically significant difference between female and male patients of the same group, and between the same gender in different groups. Regarding the total length and the a-CSA, there was a statistically significant difference between the groups. These results indicate that class II and female patients have smaller dimensions of upper airway leading to a possible risk indicator for OSAS development.

[Prevalence of antibody to hepatitis C virus in hospital personnel]. / Prevalenza dell'anticorpo contro il virus dell'epatite C nel personale ospedaliero.

UNLABELLED: Prevalence of antibody to hepatitis C virus (anti-HCV) has been widely investigated in many categories; however no data are available on hospital personnel. The aim of our study was to investigate whether hospital personnel are at risk for HCV infection. METHODS: sera collected during a prospective study on HBV infection in hospital workers done in our institution in 1985 were analyzed for the ELISA test for anti-HCV from Ortho Diagnostic System. Sera were stored at -20 degrees C and were never defrosted until tested. A population of a consecutive series of healthy volunteer blood donors was used as a control group. RESULTS: the anti-HCV prevalence was higher in hospital personnel, than in blood donors (4.5 versus 1.1, p less than 0.001, Odds Ratio 4.5, Confidence Limits 2.9-7.2). CONCLUSION: although anti-HCV is not an "ideal" test for epidemiological purposes, our study suggests that hospital personnel is at high risk for HCV infection.