Enhancement filters are potentially supposed to improve the diagnostic performance of digital images. Thus, the aim of this study was to compare the performance of digital radiography with and without enhancement filters for the detection of induced proximal caries lesions. The total sample consisted of 120 sound human teeth (40 premolars, 80 molars). Enamel subsurface demineralization was induced in one of the proximal surfaces of 60 teeth. Standardized radiographs of all teeth were acquired after the demineralization phase using the Digora-Optime  system. Four radiologists examined the digital radiographs and applied the following filters provided by the Digora  for Windows 2.6 package: Negative, Sharpen and both (Negative plus Sharpen). Validation of radiographic diagnosis was carried out by Knoop cross-sectional microhardness profiling on the proximal surfaces. Intraobserver agreement was estimated using Kappa statistics (k). Sensitivity, specificity and overall accuracy were compared using ANOVA/Tukey test (a = 5%). Intraobserver agreement ranged from good to very good/optimal (k: 0.65-0.83). Although not statistically significant, the highest sensitivity (0.68 ± 0.22) and accuracy (0.76 ± 0.16) values were observed using the Sharpen filter as opposed to the Negative filter, which presented the lowest performance indices (0.57 ± 0.13 and 0.70 ± 0.10, respectively). Specificity ranged from 0.84 to 0.85, considering all imaging modalities (p > 0.05). Insofar as the Sharpen filter had the highest performance indices, it may be considered a useful adjunct for detecting subtle proximal caries lesions.

Aim: This experimental study investigated the association between masticatory hypofunction and mandibular morphological dimensions and internal bone characteristics. Methods: Twentyfour 21-day-old male Wistar rats were randomly divided into two groups, according to the diet consistency. The control group (CG) was fed a solid diet (pellets) and the experimental group (EG) received a powdered diet during 50 days. All animals were euthanized and their mandibles removed and processed for histomorphometric analysis. A calibrated examiner performed linear and angular measurements (mandibular body length and height, mandibular lengths, ramus depth and height, mandibular base depth, mandibular head and gonial angle) on photographs, estimated bone density in the mandibular ramus region on digital radiographs and assessed the area of cortical and trabecular bone tissue in the second molar region, in 5-µm-thick serial cuts stained with Cason's Trichrome. Measurements for the study groups were compared using Mann-Whitney test (α=0.05). Results: some of the macroscopic dimensions evaluated on photographs were significantly smaller in EG compared to CG, specifically mandibular ramus height (10.77 mm vs. 11.11 mm, p=0.0375), mandibular body length (21.67 mm vs. 22.36 mm, p=0.0165) and height (4.24 mm vs. 4.54 mm, p=0.0016), as well as mandibular base depth (1.24 mm vs. 1.47 mm, p=0.0325). The relative mineral bone density was significantly decreased in EG (1.04) compared to CG (1.25), p<0.001. Rats in the EG also presented smaller trabecular and cortical bone area (2.36 mm²) than those in CG (3.16 mm²), p<0.001. Conclusions: Based on the above-mentioned measurements, it may be concluded that masticatory hypofunction induced by a powdered diet affected mandibular morphology and was associated with significantly reduced bone content.

Objectives: The aim of this study was to assess the performance of photostimulable storage phosphor (PSP) radiographs with or without using the sharpen filter and cone beam CT (CBCT) for detecting enamel subsurface demineralization. Methods: Enamel subsurface demineralization was induced on one of the approximal surfaces of 120 sound human teeth. Standardized images of all teeth were acquired after the demineralization phase using the Digora ® Optime (Orion Corp./Soredex, Helsinki, Finland) (PSP) and the i-CAT™ (Imaging Sciences International, Hatfield, PA) (CBCT) systems. Three calibrated observers interpreted the images using a five-point scale (1, demineralization definitely absent; 2, demineralization probably absent; 3, unsure; 4, demineralization probably present; and 5, demineralization definitely present). Diagnoses were validated by cross-sectional microhardness profiling in the test areas of the approximal surfaces. Interobserver agreement was analysed using kappa statistics. Accuracy was estimated by the areas under the receiver operating characteristic curves (A z ), which were compared using the Kruskal-Wallis test (a 5 5%). Results: Interobserver agreement was higher for CBCT (k 5 0.7-0.8), followed by sharpenfiltered (k 5 0.6-0.7) and original (k 5 0.5-0.6) images. CBCT presented the highest accuracy value (A z 5 0.897) compared with the original (A z 5 0.792) and sharpen-filtered (A z 5 0.712) images. However, no statistical differences were observed between the imaging modalities (p 5 0.0794). Conclusions: It can be concluded that PSP radiographs with or without using the sharpen filter and the CBCT images may be useful adjuncts for detecting subtle approximal enamel demineralization. Dentomaxillofacial Radiology (2013Radiology ( ) 42, 20120313. doi: 10.1259 Cite this article as: Belém MDF, Tabchoury CPM, Ferreira-Santos RI, Groppo FC, HaiterNeto F. Performance of a photostimulable storage phosphor digital system with or without the sharpen filter and cone beam CT for detecting approximal enamel subsurface demineralization.

We evaluated lateral pterygoid muscle volume in closed and open mouth positions in association with anterior disc displacement, effusion and abnormal articular disc shape from three-dimensional reformations of MRI. A total of 24 MRI of a sample (15 females, 9 males) aged 19-64 years (37.2 years±11.4) were assessed. Segmentation and volumetric assessment of the total, upper and lower heads of the lateral pterygoid muscle were performed using free software. The upper head of the lateral pterygoid muscle had a smaller volume than the lower head at both sides, in the closed- and open-mouth positions. In the open-mouth position, individuals with a subdivided upper head, where one component was inserted in the articular disc and another in the mandibular head, displayed a significantly larger volume of the upper head compared to individuals who had a single attachment to the articular disc (p=0.0130). The lateral pterygoid muscle has different volumes in the closed- and open-mouth positions. Gender affected muscle volume, specifically the upper head component. Insertion type in the upper head also seemed to affect muscle volume.

Although CBCT imaging must not be used exclusively for this purpose, it may be suitable for skeletal maturity assessments.