COMPUTED TOMOGRAPHY IMAGING STRATEGIES AND PERSPECTIVES IN ORBITAL FRACTURES

Objective:

The objective of this study was to demonstrate the sensitivity and specificity of multislice computed tomography (CT) for diagnosis of orbital fractures following different protocols, using an independent workstation.

Materials and methods:

CT images of 36 patients with maxillofacial fractures (symptomatic to orbit region) who were submitted to multislice CT scanning were analyzed, retrospectively. The images were interpreted based on 5 protocols, using an independent workstation: 1) axial (original images); 2) multiplanar reconstruction (MPR); 3) 3D images; 4) association of axial/MPR/3D images and 5) coronal images. The evaluated anatomical sites were divided according to the orbital walls: lateral (with or without zygomatic frontal process fracture); medial; superior (roof) and inferior (anterior, medial). The collected data were analyzed statistically using a validity test (Youden''s J index; p<0.05). The clinical and/or surgical findings (medical records) were considered as the gold standard to corroborate the diagnosis of the anatomical localization of the orbital fracture.

Results:

3D-CT scanning presented sensitivity of 78.9%, which was not superior to that of MPR (84.0%), axial/MPR/3D (90.5%) and coronal images (86.1%). On the other hand, the diagnostic value of axial images was considered limited for orbital fractures region, with sensitivity of 44.2%.

Conclusions:

Except for the axial images, which presented a low sensitivity, all methods evaluated in this study showed high specificity and sensitivity for the diagnosis of orbital fractures according to the proposed methodology. This protocol can add valuable information to the diagnosis of fractures using the association of axial/MPR/3D with multislice CT.     

Brazilian gutta-percha points. Part II: thermal properties

This study was undertaken to explore the effect of heating on gutta-percha, analyzing the occurrence of endothermic peaks corresponding to the transformation that occurs in the crystalline structure of the polymer during thermal manipulation. This study also sought to determine the temperature at which these peaks occur, causing a transformation from the beta- to the alpha-form, and from the alpha- to the amorphous phase. Eight nonstandardized gutta-percha points commercially available in Brazil (Konne, Tanari, Endopoint, Odous, Dentsply 0.04, Dentsply 0.06, Dentsply TP, Dentsply FM) and pure gutta-percha (control) were analysed using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The transition temperatures were determined and analysed. With the exception of Dentsply 0.04 and Dentsply 0.06, the majority of the products showed thermal behaviour typical of beta-gutta-percha, with two endothermic peaks, exhibiting two crystalline transformations upon heating from ambient temperature to 130 degrees. Upon cooling and reheating, few samples presented two endothermic peaks. It was concluded that heating dental gutta-percha to 130 degrees C causes changes to its chemical structure which permanently alter its physical properties.     

Tonsillolith: a report of three clinical cases

Tonsillolith is a rare dystrophic calcification as a result of chronic inflammation of the tonsils. Three asymptomatic cases of tonsillolith are reported, incidentally discovered through panoramic radiographs, which showed different sizes of radiopaque images, varying from 2 to 5 mm; cases I and III images did not overlap the mandible ramus, which led to a probable diagnosis of soft tissue calcification. Case II had radiopaque unilateral images, with osseous tissue density, overlapping the mandibular ramus, leading to a benign intra-osseous lesion, which was considered as differential diagnosis. No symptoms were reported in any case. Only case I had clinical characteristics, showing highly consistent white plaques partially visible through the mucosa. Computed tomography of the maxillofacial region/head and neck were requested to find out the exact location of these images, since most of the overlapping radiopaque images in the mandibular ramus were very similar to intra-osseous abnormalities. The computed tomography showed hyperdense images in the palatine tonsils, confirming the diagnosis of tonsillolith. The patients are currently under follow-up. No treatment is required if there is no symptom. In conclusion, tonsillolith might show images on panoramic radiographs similar to intra osseous abnormalities. The diagnosis is relatively easy when computed tomography is requested, although the images are not pathognomonic. Therefore, clinicians should consider other pathologies as differential diagnosis.     

Transforming a hospital nursing research fellowship into an evidence-based practice fellowship

An established hospital-based nursing research fellowship program was transformed into an evidence-based practice fellowship despite its previous high satisfaction ratings from nursing leaders and nurse fellow participants. The faculty for the fellowship program determined that the long-term outcomes of the research program were insufficient in light of the hospital resources committed to the fellowship program. An evidence-based practice approach was then created in anticipation that greater short-term and more sustained longer-term benefits for the hospital would be realized. The transformation of the fellowship and the short-term outcomes are described.     

EFFECT OF CAST RECTIFIERS ON THE MARGINAL FIT OF UCLA ABUTMENTS

Objectives:

This study assessed the effect of cast rectifiers on the marginal misfit of cast UCLA abutments compared to premachined UCLA abutments. The influence of casting and porcelain baking on the marginal misfit of these components was also investigated.

Methods:

Two groups were analyzed: test group – 10 cast UCLA abutments, finished with cast rectifier and submitted to ceramic application; control group – 10 premachined UCLA abutments, cast with noble metal alloy and submitted to ceramic application. Vertical misfit measurements were performed under light microscopy. In the test group, measurements were performed before and after the use of cast rectifiers, and after ceramic application. In the control group, measurements were performed before and after casting, and after ceramic application. Data were submitted to statistical analysis by ANOVA and Tukey''s test (α= 5%).

Results:

The use of cast rectifiers significantly reduced the marginal misfit of cast UCLA abutments (from 25.68μm to 14.83μm; p<0.05). After ceramic application, the rectified cylinders presented misfit values (16.18μm) similar to those of premachined components (14.3 μm). Casting of the premachined UCLA abutments altered the marginal misfit of these components (from 9.63 μm to 14.6 μm; p<0.05). There were no significant changes after porcelain baking, in both groups.

Conclusion:

The use of cast rectifiers reduced the vertical misfit of cast UCLA abutments. Even with carefully performed laboratory steps, changes at the implant interface of premachined UCLA abutments occurred. Ceramic application did not alter the marginal misfit values of UCLA abutments.     

Aneurysmal bone cyst of the mandible: case presentation and review of the literature

The aneurysmatic osseus cyst is a very infrequent bone lesion which in some occasions can be found at the craniofacial skeleton. Among all the cystic lesions that can be found at the mandible or the maxilla it is very rare. On the other side it is at the same time very interesting in terms of its differential diagnose with other types of maxillary bone lesions We present the case of a Caucasian male with an aneurysmatic cyst located at the right angle of the mandible and a review of the literature concerning the case. We have focused on the differential diagnose, mainly with the malignancies that can be found at this location. We also comment the therapeutic options classically described for these kind of pathologies. In our patient, the surgical excision allowed a complete removal of the lesion and a posterior bone healing which made possible a implant-supported rehabilitation of the edentulous segment.