Diagnosis of alveolar and root fractures in macerated canine maxillae: a comparison between two different CBCT protocols.

OBJECTIVES: To compare two small-field-of-view (FOV) CBCT protocols with different voxel sizes and number of frames for the diagnosis of root and alveolar fractures in macerated canine maxillae. METHODS: 80 incisor teeth from the canine species were inserted in 80 anterior alveolar sockets of 20 canine maxillae. An operator randomly divided each maxilla site (80 sites in total) into 4 equal groups of 20 sites: 1 (sound tooth and non-fractured alveolar socket); 2 (sound tooth and fractured alveolar socket); 3 (fractured root and non-fractured alveolar socket); and 4 (fractured root and fractured alveolar socket). The CBCT images were obtained using two different protocols: normal (N) (voxel 0.20 mm, 400 frames and radiation exposure 5.6 mGy) and high definition (HD) (voxel 0.15 mm, 500 frames and radiation exposure 7.0 mGy). RESULTS: Sensitivity numbers for alveolar fractures were lower than specificity, resulting in comparable areas under the receiver operating characteristic curves (AUC) for both protocols. Sensitivity, specificity and AUC for N and HD protocols were very similar for root fractures. When comparing AUC for both N and HD protocols by submitting them to Student's t-test, the comparison among the curves produced statistically non-significant results for alveolar fractures and root fractures likewise. CONCLUSIONS: Our findings demonstrated that the elected protocol for the diagnosis of root and alveolar fractures was N. This protocol allowed similar diagnosis results than HD protocol; however, with a lower amount of radiation exposure for the patient (5.6 mGy for N vs 7.0 mGy for HD).

Dental trauma prevention with mouthguard in a nose fracturing blow to the face: Case report.

Orofacial injuries are common in sports activities and may vary in complexity and the tissues involved. Most sports-related trauma occurs when a player hits another player, an object or the ground. This report presents a case of an injury caused by a punchlike blow to the face during a handball college team practice session. The patient suffered a traumatic blow to the left side of the nose and mouth and promptly attended a dentist. After a clinical examination and a CBCT scan, the following injuries were diagnosed: upper lip laceration, upper left lateral incisor subluxation and anterior nasal spine fracture. More severe teeth injuries were likely prevented because the patient was wearing a mouthguard.

Clinical and imagiological findings of central giant cell lesion and cherubism.

Cone beam computed tomography (CBCT) is the best examination for bone lesions of the maxilla, allowing the dentist to evaluate precisely the behavior and components of the lesion and their relationship to the surrounding structures. Central giant cell lesion and cherubism are histologically very similar lesions. Therefore clinical and radiological examinations are fundamentally important for the diagnosis. The aim of this paper is to report two cases diagnosed as central giant cell lesions and cherubism using CBCT. This imaging modality was very important for the diagnosis of the lesions presented in the current study. It also allowed observing precisely the limits of the lesions, the components, the behavior and the exact relationship to adjacent structures.

Clinical and imagiological findings of central giant cell lesion and cherubism

Cone beam computed tomography (CBCT) is the best examination for bone lesions of the maxilla, allowing the dentist to evaluate precisely the behavior and components of the lesion and their relationship to the surrounding structures. Central giant cell lesion and cherubism are histologically very similar lesions. Therefore clinical and radiological examinations are fundamentally important for the diagnosis. The aim of this paper is to report two cases diagnosed as central giant cell lesions and cherubism using CBCT. This imaging modality was very important for the diagnosis of the lesions presented in the current study. It also allowed observing precisely the limits of the lesions, the components, the behavior and the exact relationship to adjacent structures.

A tomografia computadorizada de feixe cônico (TCFC) é o melhor exame para lesões ósseas da maxila, permitindo que o dentista possa avaliar com mais confiabilidade o comportamento, os componentes da lesão, e sua relação com estruturas adjacentes. A Lesão central de células gigantes e o querubismo são patologias muito semelhantes histologicamente, portanto, exames clínicos e radiológicos são de fundamental importância para o diagnóstico. O objetivo deste trabalho é relatar dois casos diagnosticados usando TCFC, um de lesões centrais de células gigantes e um de querubismo. Esta modalidade de imagem foi muito importante para o diagnóstico das patologias apresentadas neste estudo. Também permitiu observar com mais confiabilidade os limites das lesões, os componentes, o comportamento e a relação exata com as estruturas adjacentes.

Influence of dental metallic artifact from multislice CT in the assessment of simulated mandibular lesions.

OBJECTIVE: This study evaluated the influence of metallic dental artifacts on the accuracy of simulated mandibular lesion detection by using multislice technology. MATERIAL AND METHODS: Fifteen macerated mandibles were used. Perforations were done simulating bone lesions and the mandibles were subjected to axial 16 rows multislice CT images using 0.5 mm of slice thickness with 0.3 mm interval of reconstruction. Metallic dental restorations were done and the mandibles were subjected again to CT in the same protocol. The images were analyzed to detect simulated lesions in the mandibles, verifying the loci number and if there was any cortical perforation exposing medullar bone. The analysis was performed by two independent examiners using e-film software. RESULTS: The samples without artifacts presented better results compared to the gold standard (dried mandible with perforations). In the samples without artifacts, all cortical perforation were identified and 46 loci were detected (of 51) in loci number analysis. Among the samples with artifacts, 12 lesions out of 14 were recognized regarding medullar invasion, and 40 out of 51 concerning loci number. The sensitivity in samples without artifacts was 90% and 100% regarding loci number and medullar invasion, respectively. In samples with artifacts, these values dropped to 78% and 86%, respectively. The presence of metallic restorations affected the sensitivity values of the method, but the difference was not significant (p>0.05). CONCLUSIONS: Although there were differences in the results of samples with and without artifacts, the presence of metallic restoration did not lead to misinterpretation of the final diagnosis. However, the validity of multislice CT imaging in this study was established for detection of simulated mandibular bone lesions.

Influence of dental metallic artifact from multislice CT in the assessment of simulated mandibular lesions

OBJECTIVE: This study evaluated the influence of metallic dental artifacts on the accuracy of simulated mandibular lesion detection by using multislice technology. MATERIAL AND METHODS: Fifteen macerated mandibles were used. Perforations were done simulating bone lesions and the mandibles were subjected to axial 16 rows multislice CT images using 0.5 mm of slice thickness with 0.3 mm interval of reconstruction. Metallic dental restorations were done and the mandibles were subjected again to CT in the same protocol. The images were analyzed to detect simulated lesions in the mandibles, verifying the loci number and if there was any cortical perforation exposing medullar bone. The analysis was performed by two independent examiners using e-film software. RESULTS: The samples without artifacts presented better results compared to the gold standard (dried mandible with perforations). In the samples without artifacts, all cortical perforation were identified and 46 loci were detected (of 51) in loci number analysis. Among the samples with artifacts, 12 lesions out of 14 were recognized regarding medullar invasion, and 40 out of 51 concerning loci number. The sensitivity in samples without artifacts was 90 percent and 100 percent regarding loci number and medullar invasion, respectively. In samples with artifacts, these values dropped to 78 percent and 86 percent, respectively. The presence of metallic restorations affected the sensitivity values of the method, but the difference was not significant (p>0.05). CONCLUSIONS: Although there were differences in the results of samples with and without artifacts, the presence of metallic restoration did not lead to misinterpretation of the final diagnosis. However, the validity of multislice CT imaging in this study was established for detection of simulated mandibular bone lesions.

Odontogenic glandular cyst: a case report.

Glandular Odontogenic Cyst (GOC) is a rare developmental cyst of the jaws. The histological features of GOC strongly suggest an origin from the remains of dental lamina. Radiographically, GOC presents as well-defined radiolucencies with uni- or multilocular appearance. A case of GOC in a 54-year-old black female is presented here. Clinical, histological and imaging features were evaluated. Due to the high tendency of recurrence and the aggressive potential of GOC, careful clinical and radiological evaluation must be carried out. CT scans are recommended because they provide accurate information about locularity of the lesion, cortical integrity, expansion of the lesion and involvement of the contiguous soft tissue.

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.

Accuracy of magnetic resonance imaging compared with computed tomography for implant planning.

AIM: The objective of this study was to evaluate the reliability of magnetic resonance imaging (MRI) compared with computed tomography (CT) for dental implant planning in respect to bone measurements. METHODS: Five dry mandibles were submitted to MRI and CT examinations. Each mandible had three specific sites identified with markers, in a total of 15 sites to be studied. The images provided by the MRI and CT examinations were delivered to four specialists in Oral and Maxillofacial Radiology to measure the bone height at the specific sites. Subsequently, the bone height of the dry mandibles was directly measured in the determined sites. The measurements obtained by the specialists in MRI and CT images were compared with the measurements obtained directly from the dry mandibles using the ANOVA test with a 0.05 significance level. RESULTS: The differences between the measurements obtained directly from the dry mandibles and the measurements from the MRI exams varied from 0.13 to 1.67 mm, with 10 sites being overestimated in MRI exams and five sites being underestimated. The differences between the measurements from the dry mandibles and CT exams varied from 0.02 to 1.25 mm, with nine sites being overestimated in CT exams and six sites being underestimated. The differences between the measurements from the MRI and CT exams varied from 0.03 to 1.00 mm, with nine sites giving higher values in MRI exams and six sites giving higher values in CT exams. There were no statistically significant differences between the three grous of measurements (P=0.98). CONCLUSION: The MRI, when compared with CT, shown to be reliable in respect to bone measurements for dental implant planning.

3-D volume rendering maxillofacial analysis of angular measurements by multislice CT.

OBJECTIVE: This study was designed to determine the precision and accuracy of angular measurements using three-dimensional computed tomography (3D-CT) volume rendering by computer systems. STUDY DESIGN: The study population consisted of 28 dried skulls that were scanned with a 64-row multislice CT, and 3D-CT images were generated. Angular measurements, (n = 6) based upon conventional craniometric anatomical landmarks (n = 9), were identified independently in 3D-CT images by 2 radiologists, twice each, and were then performed by 3D-CT imaging. Subsequently, physical measurements were made by a third examiner using a Beyond Crysta-C9168 series 900 device. RESULTS: The results demonstrated no statistically significant difference between interexaminer and intraexaminer analysis. The mean difference between the physical and 3-D-based angular measurements was -1.18% and -0.89%, respectively, for both examiners, demonstrating high accuracy. CONCLUSION: Maxillofacial analysis of angular measurements using 3D-CT volume rendering by 64-row multislice CT is established and can be used for orthodontic and dentofacial orthopedic applications.

Influência do nível de experiência doexaminador na interpretação de radiografias obtidas através da técnica convencional e da subtração radiográfica digital (srd) / Influence of the examiner level of experience in diagnostic of radiographies taken by both

Este estudo propôs-se a avaliar através de técnica radiográfica convencional e SRD, a influência do nível de experiência do examinador no diagnóstico de lesões infra-ósseas. Quarenta e oito defeitos foram confeccionados nas cristas ósseas, utilizando-se brocas esféricas de diferentes diâmetros. O processamento automatizado das películas foi seguido da digitalização das imagens (500 dpi / 8bits). A técnica de SRD foi realizada utilizando-se o programa de computador AxionVisionv 4.3. As películas radiográficas e as imagens subtraídas foram codificadas. Quatro examinadores com diferentes níveis de experiência diagnosticaram as lesões (presente ou ausente), com intervalo de 15 dias entre os exames. Foram calculados os valores de sensibilidade (S) e especificidade (E), associação (testequi-quadrado) entre resultados e concordância inter-examinadores (teste Kappa). A técnica convencional mostrou valores médios de S = 13,28% e E = 93,46%,, enquanto que a SRDrevelou S = 37,61% e E = 91,22%. Conclui-se que a experiênciado examinador teve maior influência sobre a técnica convencionale que a SRD foi capaz de melhorar a S de diagnóstico, independentemente do nível de experiência do examinador sendo mais sensível para a detecção de pequenas lesões periodontais.

Squamous-cell carcinoma arising from an odontogenic cyst--the importance of computed tomography in the diagnosis of malignancy.

Primary intraosseous carcinoma of the mandible is rare, and when it occurs often arises within or closely associated with an odontogenic cyst. The purpose of this article is to show the role of computed tomography (CT) in the early detection of carcinomatous changes, because of its specificity in establishing the nature of the lesion. An unusual case of a squamous cell carcinoma that arose in an odontogenic cyst is described. The appearance on the panoramic radiograph was suggestive of a benign cystic lesion in the left side of the mandible, but when a CT scan was performed, the appearance of the lesion was compatible with malignancy. Histopathological analysis confirmed the suspicion of a squamous cell carcinoma, but without CT investigation it would be impossible to demonstrate that carcinomatous change had developed from a cystic lesion.

The contribution of trabecular bone to the visibility of the lamina dura: an in vitro radiographic study.

OBJECTIVE: The objective of this study was to determine the degree to which trabecular bone contributes to the radiographic visibility of lamina dura. STUDY DESIGN: Segments of human cadaver mandible were obtained and split longitudinally. Two identical radiographs were made of each segment (1) before the removal of any additional bone and after (2) the removal of a small amount of the lamina dura at the apex of a tooth, (3) block removal of trabecular bone, and (4) smoothing of the endosteal surface of the external cortex. The radiographs were projected in random pairs for each sample. Six dentists judged whether a difference in the amount of lamina dura could be detected between 2 sets of radiographs. RESULTS: Chi-square analysis revealed a significant radiographic difference between radiographs made initially and after removal of the lamina dura and trabecular bone. CONCLUSIONS: Fewer than half of the changes of lamina dura loss alone could be detected radiographically by the observing dentists, whereas nearly all cases of the loss of periapical lamina dura in conjunction with loss of trabecular bone could be detected.