Marcelo Augusto Oliveira de Sales

Assessment of linear and angular measurements on three-dimensional cone-beam computed tomographic images

OBJECTIVE The purpose of this research was to provide further evidence to demonstrate the precision and accuracy of maxillofacial linear and angular measurements obtained by cone-beam computed tomography (CBCT) images. STUDY DESIGN The study population consisted of 15 dry human skulls that were submitted to CBCT, and 3-dimensional (3D) images were generated. Linear and angular measurements based on conventional craniometric anatomical landmarks, and were identified in 3D-CBCT images by 2 radiologists twice each independently. Subsequently, physical measurements were made by a third examiner using a digital caliper and a digital goniometer. RESULTS The results demonstrated no statistically significant difference between inter- and intra-examiner analysis. Regarding accuracy test, no statistically significant differences were found of the comparison between the physical and CBCT-based linear and angular measurements for both examiners (P = .968 and .915, P = .844 and .700, respectively). CONCLUSIONS 3D-CBCT images can be used to obtain dimensionally accurate linear and angular measurements from bony maxillofacial structures and landmarks.

SAPHO syndrome with temporomandibular joint ankylosis: clinical, radiological, histopathological, and therapeutical correlations

The SAPHO syndrome is characterized by specific clinical manifestations of synovitis, acne pustulosis, hyperostosis, and osteitis. It is a rare disease with a combination of osseous and articular manifestations associated with skin lesions. We describe a patient with SAPHO syndrome of the mandible and involvement of the temporomandibular joint (TMJ ankylosis). The findings from orthopantomography, computed tomography (CT), and clinical and histopathological examinations are compared and analyzed to improve the final diagnosis. Our patient was submitted to a bilateral high condylectomy and coronoidectomy to correct the open mouth limitation. No previous report of SAPHO syndrome associated with secondary TMJ ankylosis was found in the literature.

Assessment of open source software for CBCT in detecting additional mental foramina

The purpose of this study was to evaluate which post-processing imaging protocol would be better to analyze the additional mental foramen (AMF) in preoperative planning with cone-beam computed tomography (CBCT) exams, and to test reproducibility of measurements, using open source software (OsiriX). The software was used to detect the cases of AMF from among 58 exams for dental implant planning in edentulous mandible areas-three cases were found. The case images were submitted to qualitative analysis using 2D orthogonal MPR, 3D-MPR and 3D volume rendering protocols by two oral and maxillofacial radiologists. Quantitative analysis used the 3D-MPR protocol; the closed polygon tool measured the mental foramen (MF) and the AMF areas; the length tool measured the distance between foramina. The measurements were performed independently by the examiners, at two different times. Intra- and interexaminer agreement was assessed using the intraclass correlation coefficient. The panoramic view did not show the MF and the AMF clearly. The AMF could be detected in the parasagittal view. 2D Orthogonal MPR was effective to observe the AMF in some cases. The 3D-MPR and 3D view protocols were the most effective to locate and analyze the AMF. In conclusion, a 3D view improves visualization when anatomical points are not clearly visible. 3D-MPR was considered a more effective post-processing imaging protocol to observe foramina relationships. The high reproducibility of measurements for anatomical MF variations was established using specific tools featured in open source software for CBCT. OsiriX is realistic and recommended for preoperative planning.

Comparison between cone-beam and multislice computed tomography for identification of simulated bone lesions

There are many studies that compare the accuracy of multislice (MSCT) and cone beam (CBCT) computed tomography for evaluations in the maxillofacial region. However, further studies comparing both acquisition techniques for the evaluation of simulated mandibular bone lesions are needed. The aim of this study was to compare the accuracy of MSCT and CBCT in the diagnosis of simulated mandibular bone lesions by means of cross sectional images and axial/MPR slices. Lesions with different dimensions, shape and locularity were produced in 15 dry mandibles. The images were obtained following the cross sectional and axial/MPR (Multiplanar Reconstruction) imaging protocols and were interpreted independently. CBCT and MSCT showed similar results in depicting the percentage of cortical bone involvement, with great sensitivity and specificity (p < 0.005). There were no significant intra- or inter-examiner differences between axial/MPR images and cross sectional images with regard to sensitivity and specificity. CBCT showed results similar to those of MSCT for the identification of the number of simulated bone lesions. Cross sectional slices and axial/MPR images presented high accuracy, proving useful for bone lesion diagnosis.

Effect of field of view in the detection of chemically created peri-implant bone defects in bovine ribs using cone beam computed tomography: an in vitro study

OBJECTIVES To assess the accuracy of cone beam computed tomography (CBCT) using two fields of view (FOVs) in the diagnosis of peri-implant defects. STUDY DESIGN Eighty implants were placed in bovine ribs, in which peri-implant bone defects of two sizes (T1 and T2) were simulated using 70% perchloric acid. CBCT images were acquired with the use of two FOV size settings of the i-CAT NG unit: 6 × 16 cm and 8 × 8 cm. One oral and maxillofacial surgeon (OMS) and two oral and maxillofacial radiologists (OMRs) evaluated the presence of defects, and their findings were compared with direct visual evaluation. The kappa (κ)-statistic, area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the examinations were calculated. AUC values were compared with the Student t test. RESULTS The obtained κ-values indicated good intra- and interobserver agreement. A significant difference was found between T1 and T2 (P = .01) with regard to AUC values, and no significant difference was found between the different FOVs in both test groups (T1, P = .06; T2, P = .33). The sensitivity, specificity, PPV, and NPV of the examinations were higher for the OMRs than for the OMS involved in the study. CONCLUSIONS The ability of CBCT to detect chemically created peri-implant bone defects was good, especially for larger defects (Group T2) but only for the observations of the OMRs. The observations of the OMS were less accurate. The two FOVs tested were appropriate to detect peri-implant bone defects.

The emerging role of maxillofacial radiology in the diagnosis and management of patients with complex periodontitis

Contemporary periodontal therapy has evolved to become more interdisciplinary and increasingly involves more complex treatments, including bone and soft-tissue regenerative procedures. Therapeutic options require an imaging modality or combination of techniques that are capable of providing a diagnostic osseous baseline and facilitating quantification of smaller increments of bony change, both loss and additive, which are comparable over time. Intra-oral and panoramic radiography are the modalities most commonly used to identify the location, quantify the amount and the pattern of alveolar bone loss and determine response to therapy. Cone-beam computed tomography imaging offers specific advantages for periodontal diagnosis in that three-dimensional images of dental and alveolar bone structures can be rendered with accuracy. Cone-beam computed tomography has been shown to be clinically efficacious in demonstrating localized defects, such as furcation involvement and intrabony vertical and buccal/lingual defects, and in assessing the effects of regenerative therapy. In these situations, limited-field-of-view, high-resolution protocols are indicated.

Effectiveness of Periapical Radiography Versus Cone Beam Computed Tomography with Different Kilovoltage Settings in the Detection of Chemically Created Peri-implant Bone Defects: An In Vitro Study

PURPOSE To determine the effectiveness of cone beam computed tomography (CBCT) images obtained with different kilovoltage settings compared with intraoral periapical photostimulable storage phosphor (PSP) plate images in the detection of chemically created peri-implant defects utilizing a bovine rib bone model in vitro. MATERIALS AND METHODS After placing 80 implants in bovine ribs, peri-implant circumferential bone defects of different sizes were created with 70% perchloric acid. CBCT images (3D Accuitomo 170) were acquired at 90 and 75 kVp, and intraoral periapical images were acquired using a PSP system (Carestream KODAK, CS 7600). Using a 5-point Likert scale, two oral and maxillofacial radiologists (OMR) and two oral and maxillofacial surgeons (OMS) evaluated the likelihood of a bone defect being absent or present. The kappa statistic was used to compare observer agreement, and area under the curve values were compared using analysis of variance and the post hoc Tukey test. Significance was set at P ≤ .05. RESULTS PSP reliability ranged from discordance to slight for small defects and fair to moderate for larger defects. For CBCT, OMRs had good agreement for defects using 90 kVp, and slight to fair using 75 kVp. Agreement for OMS observations was fair for 75 kVp, and varied from slight to good for 90 kVp. Small lesions were detected more effectively by CBCT than by PSP, and larger lesions were detected more effectively by CBCT at 90 kVp than by CBCT at 75 kVp or by PSP. CONCLUSION CBCT imaging at 90 kVp was associated with a significantly higher rate of detection of both small and large chemically simulated bone defects than PSP or CBCT at 75 kVp. CBCT imaging at 75 kVp proved better than PSP for the detection of small defects.

Reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications

Objective The present study evaluated the reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications. Materials and Methods Thirty-five patients under high-risk for development of carotid artery calcifications who had digital panoramic radiography were referred to undergo ultrasonography. Thus, 70 arteries were assessed by both methods. The main parameters utilized to evaluate the panoramic radiography reliability in the diagnosis of carotid artery calcifications were accuracy, sensitivity, specificity and positive predictive value of this method as compared with ultrasonography. Additionally, the McNemars test was utilized to verify whether there was a statistically significant difference between digital panoramic radiography and ultrasonography. Results Ultrasonography demonstrated carotid artery calcifications in 17 (48.57%) patients. Such individuals presented with a total of 29 (41.43%) carotid arteries affected by calcification. Radiography was accurate in 71.43% (n = 50) of cases evaluated. The degree of sensitivity of this method was 37.93%, specificity of 95.12% and positive predictive value of 84.61%. A statistically significant difference (p < 0.001) was observed between the methods evaluated in their capacity to diagnose carotid artery calcifications. Conclusion Digital panoramic radiography should not be indicated as a method of choice in the investigation of carotid artery calcifications.

Correlação clínico-tomográfica em patologias dos seios maxilares: avaliação por meio de tomografia computadorizada por feixe cônico

Resumen pt: Objetivo: Analisar os achados tomograficos fortuitos em seios maxilares por meio de exames de Tomografia Computadorizada por Feixe Conico, bem como sua c...

Impact of Image Filters and Observations Parameters in CBCT for Identification of Mandibular Osteolytic Lesions

The aim of this study was to analyze the influence of filters (algorithms) to improve the image of Cone Beam Computed Tomography (CBCT) in diagnosis of osteolytic lesions of the mandible, in order to establish the protocols for viewing images more suitable for CBCT diagnostics. 15 dry mandibles in which perforations were performed, simulating lesions, were submitted to CBCT examination. Two examiners analyzed the images, using filters to improve image Hard, Normal, and Very Sharp, contained in the iCAT Vision software, and protocols for assessment: axial; sagittal and coronal; and axial, sagittal and coronal planes simultaneously (MPR), on two occasions. The sensitivity and specificity (validity) of the cone beam computed tomography (CBCT) have been demonstrated as the values achieved were above 75% for sensitivity and above 85% for specificity, reaching around 95.5% of sensitivity and 99% of specificity when we used the appropriate observation protocol. It was concluded that the use of filters (algorithms) to improve the CBCT image influences the diagnosis, due to the fact that all measured values were correspondingly higher when it was used the filter Very Sharp, which justifies its use for clinical activities, followed by Hard and Normal filters, in order of decreasing values.