Iêda Margarida Rocha Crusoé-Rebello

Accuracy of linear measurements in cone beam computed tomography with different voxel sizes.

Objective: To evaluate the accuracy of linear measurements on dry mandible specimens using cone beam computed tomography (CBCT) images acquired with different voxel sizes. Methodology: Eight human dry mandibles were submitted to CBCT examination, using the i-CAT (Imaging Sciences, Inc. Hatfield, PA) device and four protocols with different voxel sizes. Tomographic slices with a more central view of the markers, placed on six sites on each mandible, were selected to perform measurements. Values obtained from direct measurements on the dry mandible after sectioning them on the preestablished sites were compared with measurements from the tomographic images and the measurement error. Results: There was no statistical difference between the measurement error of the protocols (P = 0.606). The mean value of the difference between the values obtained in the images and the dry mandible was smaller than 1 mm for all the protocols. Conclusion: The accuracy of vertical and horizontal measurements, using CBCT (i-CAT) for the four protocols, was shown to be comparable with the measurements performed on the dry mandible.

Evaluation of the relation between the horizontal condylar angle and the internal derangement of the TMJ - a magnetic resonance imaging study

This research aimed at assessing the relation between the horizontal condylar angle (HCA) and the internal derangement (ID) of the temporomandibular joint (TMJ), as a result of interference by the TMJ disk, in individuals undergoing magnetic resonance (MR) scans. The sample included a total of 144 TMJs (sagittal and coronal views) of 72 subjects, 15 of whom were male and 57 female, with ages ranging from 15 to 70. The scans were made in a Signa system (GE) model at a magnetic field magnitude of 1.5 T. Sixty-eight TMJs were found to be normal, while 46 showed anterior displacement with reduction. Of these, 41 had some kind of adaptive change in the condyle, while 5 showed degenerative changes. Anterior displacement without reduction was found in 29 joints, 12 of which showed adaptative changes in the condyle, while 17 showed degenerative changes. Only one posterior displacement of the articular disk was recorded. For the TMJs in which disk displacement was found, such values achieved 24.69 on the right side, and 22.94 on the left side. Hence, it was possible for us to conclude that the HCA tends to increase in those TMJs where ID is present. For contralateral TMJs, a strong association was observed between HCA values (57.8%), state of normality (69.7%), and ID (66.7%). To corroborate such findings, a correlation between contralateral HCA values (63.31%) and the diagnosis for contralateral TMJs (68.05%) was determined. Thus, we could infer that there is a tendency between contralateral TMJs to share characteristics and conditions.

Multiple Stafne Bone Defects: A Rare Entity

Stafne bone defects (SBDs) are generally located in the lingual cortex, close to the mandibular angle. We report the occurrence of multiple SBDs in an asymptomatic patient, a 60-year-old man, referred to a radiology clinic to undergo examination for the purpose of implant planning. The case of multiple SBD presented here, probably the first reported in the literature, reinforces the hypothesis that some cases of SBD may be the result of a focal failure during the ossification of the mandible.

Stafne's Defect with Buccal Cortical Expansion: A Case Report

A rare case of Stafnes bone cavity, type III-G, is reported in a 49-year-old male patient who had been referred to a private clinic for a routine evaluation. The final diagnosis was based on computed tomography. Scintigraphy played a fundamental role in determining the most likely etiology.