Quantitative assessment of image artifacts from root filling materials on CBCT scans made using several exposure parameters.

PURPOSE: To quantify artifacts from different root filling materials in cone-beam computed tomography (CBCT) images acquired using different exposure parameters. MATERIALS AND METHODS: Fifteen single-rooted teeth were scanned using 8 different exposure protocols with 3 different filling materials and once without filling material as a control group. Artifact quantification was performed by a trained observer who made measurements in the central axial slice of all acquired images in a fixed region of interest using ImageJ. Hyperdense artifacts, hypodense artifacts, and the remaining tooth area were identified, and the percentages of hyperdense and hypodense artifacts, remaining tooth area, and tooth area affected by the artifacts were calculated. Artifacts were analyzed qualitatively by 2 observers using the following scores: absence (0), moderate presence (1), and high presence (2) for hypodense halos, hypodense lines, and hyperdense lines. Two-way ANOVA and the post-hoc Tukey test were used for quantitative and qualitative artifact analysis. The Dunnet test was also used for qualitative analysis. The significance level was set at P<.05. RESULTS: There were no significant interactions among the exposure parameters in the quantitative or qualitative analysis. Significant differences were observed among the studied filling materials in all quantitative analyses. In the qualitative analyses, all materials differed from the control group in terms of hypodense and hyperdense lines (P<.05). Fiberglass posts did not differ statistically from the control group in terms of hypodense halos (P>.05). CONCLUSION: Different exposure parameters did not affect the objective or subjective observations of artifacts in CBCT images; however, the filling materials used in endodontic restorations did affect both types of assessments.

Assessment of condyle position, fossa morphology, and disk displacement in symptomatic patients.

OBJECTIVE: The aim of the study was to determine whether there are any associations between the morphology of the glenoid fossa, articular spaces, and disk displacement by evaluating the magnetic resonance imaging (MRI) scans of symptomatic patients. Gender and age were also evaluated for any effect on the parameters. STUDY DESIGN: MRI scans of 199 temporomandibular joints were assessed for the morphology of the glenoid fossa and articular spaces in both sagittal and coronal views. The presence of disk displacement and its type in closed-mouth and open-mouth positions were also assessed. Analysis of variance (ANOVA), Tukey, and Student t tests or Mann-Whitney rank sum tests were used to investigate the associations among these variables. RESULTS: A total of 113 joints (56.8%) were presented with disk displacement. The articular spaces observed in sagittal and coronal views were, overall, significantly larger in males than in females in 3 of the 6 spaces (superior, posterior, and central spaces). Larger superior and medial articular spaces were associated with angled glenoid fossae. Higher mean values of the articular space sizes were associated with normal disk position (P < .001), except for the anterior articular space. When displacement was identified, higher values of the articular space sizes were also associated with disk reduction in the open-mouth position (P < .05). CONCLUSIONS: Condyles in the central position in the coronal view and slightly anteriorly positioned in the sagittal view are less likely to present disk displacement.

Condyle Excursion Angle, Articular Eminence Inclination, and Temporomandibular Joint Morphologic Relations With Disc Displacement.

PURPOSE: The aim of this study was to evaluate the relations of the condyle excursion angle (CEA) and the morphology and morphometry of the articular eminence to disc displacement (DD) using magnetic resonance imaging (MRI) of symptomatic patients. MATERIALS AND METHODS: MRIs of 199 temporomandibular joints (TMJs) were evaluated. Qualitative and quantitative morphologic analyses were performed with tools available in PACS 11.0 (Carestream Health, Inc, Rochester, NY). The articular eminence inclination (AEI), eminence height (EH), CEA, and articular eminence morphologic shape were evaluated. Statistical analyses were used to evaluate any possible association of the variables with DD in the closed- and open-mouth positions, age, and gender. The significance level was set at .05. RESULTS: Elderly women (>60 yr) presented higher prevalence values (43.26%). There was no statistical correlation between DD and gender (P = .4290). Higher mean values of the AEI and EH were associated with box-shaped eminences. The EH, AEI, and CEA were not related to the presence or absence of DD and the different types of DD. The AEI (P = .002) and CEA (P < .001) values were higher for TMJs with disc reduction in the open-mouth position. CONCLUSION: Disc position in the closed- and open-mouth positions is not influenced by articular eminence morphology; however, the AEI and CEA have an influence on disc reduction.

Human identification by FSS system adapted to cephalometric radiographs.

The aim of this study was to verify the applicability and reproducibility of the FSS system [8] adapted for frontal and lateral cephalometric radiographs of the frontal sinus for human identification purposes. Eighty lateral and frontal digital cephalometric radiographs from a private Dental Radiology service's database were evaluated. Evaluations were performed in a dimmed lighting room, using a 4.200 lux lightbox with mask, ultrafan paper and pencil with a 0.5 diameter tip. The sheet of paper was superimposed on the radiograph to obtain the outlines of the frontal sinus and two examiners made the drawings independently at two different times, with a minimum period interval between evaluations. To obtain the linear physical measurements of the frontal sinus, a digital pachymeter was used. Later, all the discrete variables were codded for the statistical analysis. All variables were tested by means of the Cohen's Kappa test. The intraexaminer agreement ranged from good to perfect (p<0.001), while the interexaminer agreement ranged from regular to perfect (p<0.001). The use of frontal and lateral cephalometric radiographs was found to be reproducible and reliable for human identification by an adaptation of FSS system.