Pixel gray measurement for the diagnosis of dental ankylosis in cone beam computed tomography images.

OBJECTIVE: The aim of this study was to investigate dental ankylosis in unerupted or partially erupted teeth by using cone beam computed tomography (CBCT) to quantify pixel intensity. STUDY DESIGN: In total, 157 CBCT images from individuals with a total of 206 unerupted or partially erupted teeth with suspected ankylosis were evaluated. CBCT images were analyzed for the presence of ankylosis by 2 oral radiologists by quantifying mean pixel intensities (analysis 1) and variations in pixel intensities (analysis 2) in normal and ankylosed regions. The association between ankylosis and demographic and tooth-related factors was also examined. RESULTS: Ankylosis was diagnosed in 57 teeth (27.7%). The diagnosis was established with all 3 multiplanar reconstruction views in 22 of these teeth (38.6%). In analysis 1, a higher pixel intensity was observed in areas with ankylosis compared with normal periodontal ligament (PDL) density as a result of bone deposition in this region, which is characteristic of ankylosis (P < .001). In analysis 2, reductions in pixel intensity were greater in the PDL areas than in the ankylosed areas. Ankylosis was significantly associated with the anterior teeth, the maxillary arch, single-rooted teeth, and impacted teeth (P ≤ .026). CONCLUSIONS: Our results suggest that CBCT measurement of pixel intensity may be useful for the diagnosis of ankylosis.

Análise comparativa da radiopacidade de três cimentos endodônticos por meio de radiografia digital / Comparative analysis of radiopacity among three endodontic sealers by digital radiography

A radiopacidade consiste em uma propriedade importante requerida para um material obturador, pela qual se avalia o preenchimento do sistema de canais radiculares. Objetivo: Realizar análise comparativa da radiopacidade de três cimentos endodônticos por meio de radiografia digital. Material e método: Foram confeccionadas oito placas de acrílico com quatro cavidades cada, nas quais inseriu-se os seguintes materiais: I- cimento endodôntico à base de hidróxido de cálcio (Sealapex); II- cimento endodôntico resinoso (AH PLUS); III- cimento endodôntico à base de MTA (MTA Fillapex); IV- cones de guta-percha (controle positivo). Estas placas foram radiografadas digitalmente pelo método direto e as imagens obtidas foram analisadas pelos seus níveis de tons de cinza, utilizando-se o software Image Tool for Windows versão 3.0. Resultados: Verificou-se que o Sealapex apresentou radiopacidade menor que os demais cimentos testados e grupo controle (p<0,01); e o AH Plus e MTA Fillapex não foram diferentes entre si com relação à radiopacidade (p>0,05). Conclusão: Apenas o cimento Sealapex apresentou radiopacidade diferente dos demais materiais.

The radiopacity is an important property required for a root canal filling material, since it allows proper radiographic evaluation of the treated root canal system. Objective: To carry out a comparative analysis of the radiopacity of three endodontic sealers through digital radiography. Material and methods: Eight acrylic molds were filled with the following materials: (I) calcium hydroxide t-based cement (Sealapex); II-resin-based cement (AH PLUS); III-MTA-based cement (MTA Fillapex); IVgutta- percha cones (positive control). The molds filled with the materials were digitally radiographed using the direct method and the images obtained were analyzed using a grayscale from 0 to 255 dot points inch. Results: The Sealapex cement showed the lower values of radipacity than other cements and control (p<0.01). The AH Plus and MTA Fillapex cements were not different between each other (p>0.05). Conclusion: the cements tested showed radiopacity satisfactory, being lower to the Sealapex.

Primary Extracranial Meningioma: A Rare Location.

Meningiomas are benign extraaxial tumors of the central nervous system (CNS). Extracranial meningiomas are extremely rare (2%) and can develop as a direct extension from a primary intracranial meningioma or as true primary extracranial meningioma originating from ectopic arachnoid cells. Only eight cases of primary meningioma in the jaw have been reported to date. Extracranial meningiomas are frequently misdiagnosed, resulting in inappropriate clinical management. The aim of this article was to describe the case of a man with an asymptomatic swelling in the right retromolar area over a period of 2 months. Cone beam computed tomography was performed to determine the extension and involvement of the adjacent structures. Histopathological findings and immunohistochemical analysis aided in the diagnosis of primary extracranial meningioma in the mandible and several aspects of this unusual neoplasm are reviewed. The treatment of choice was a partial resection of the mandible and reconstruction with autogenous iliac tricortical bone. Five years after surgery, the patient remains free of disease.

Pre-heating mitigates composite degradation

ABSTRACT Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey’s tests (α=5%). Results Radiopacity levels were as follows: Durafill VS<Z-350<Z-250 (p<0.05). The depth of silver penetration into the composites ranked as follows: Durafill VS>Z-350>Z-250 (p<0.05). After storage in water/NaOH, pre-heated specimens presented higher radiopacity values than non-pre-heated specimens (p<0.05). There was a lower penetration of silver in pre-heated specimens (p<0.05). Conclusions Pre-heating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth.

Glucocorticoids, calcitonin, and osteocalcin cannot differentiate between aggressive and nonaggressive central giant cell lesions of the jaws.

OBJECTIVE: To evaluate the expression of glucocorticoid receptor (GR), calcitonin receptor (CTR), and osteocalcin (OC) in aggressive and nonaggressive central giant cell lesions (CGCLs). The numbers of mitotic and multinucleated giant cells were also evaluated. STUDY DESIGN: Thirty-one cases of CGCL were submitted for immunohistochemistry. Mitotic figures and multinucleated giant cells were assessed through histochemical analyses. RESULTS: Positive staining for GR, CTR, and OC was observed in all cases studied. There were no differences between CGCL variants with regard to the expression of GR, CTR, or OC. The aggressive group showed a higher number of multinucleated giant cells compared with the nonaggressive group (P < .05). CONCLUSIONS: Nonaggressive and aggressive CGCLs cannot be distinguished by OC, CTR, or GR expression, although the number of multinucleated giant cells may help differentiate between CGCL types.

Pre-heating mitigates composite degradation.

Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey's tests (α=5%). Results Radiopacity levels were as follows: Durafill VSZ-350>Z-250 (p<0.05). After storage in water/NaOH, pre-heated specimens presented higher radiopacity values than non-pre-heated specimens (p<0.05). There was a lower penetration of silver in pre-heated specimens (p<0.05). Conclusions Pre-heating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth.

High-grade primary leiomyosarcoma in the mandible: diagnosis and treatment.

BACKGROUND: Leiomyosarcoma is a malignant tumor that originates in smooth muscle cells and is rarely found in the oral cavity. We present a case of high-grade primary leiomyosarcoma in the mandible and discuss the diagnosis process. METHODS: The patient was a 64-year-old white man who had a slight increase in volume in the left-side mandible with a radiolucent osteolytic image with the destruction of the mandibular cortex. Incisional biopsy and preoperative examination were performed, including cone beam CT and examination by immunohistochemistry that defined the histologic diagnosis of leiomyosarcoma. The patient underwent reconstruction with an osteocutaneous flap with microvascular anastomosis. RESULTS: Two years after the surgery, there was no sign of recurrence of the lesion. CONCLUSION: The use of cone beam CT to define the limits of the lesion and the immunohistochemical findings were essential to establish the treatment plan.

Forensic importance of panoramic radiographs for human identification / Importância pericial das radiografias panorâmicas para a identificação humana

Human identification is a procedure of great importance for the proceedings instituted in the various spheres of law, and is also required by the community for cultural or religious reasons. Among the processes of identification, the technique of forensic dentistry is a comparativemethodology in which it is necessary for the person to be identified to have his dental characteristics recorded in some kind of documentationproduced during his lifetime. In this context, panoramic radiographs are extra-oral images often requested by dentists due to the broad viewstructures of the oral-maxillofacial complex, which assist in obtaining the diagnosis and definition of the treatment plan. In this study, a caseof human identification was reported using a panoramic x-ray, produced more than seven years earlier to support the planning of dentaltreatment. The radiographic comparison was made possible because a post-mortem panoramic x-ray was produced, allowing the viewing ofanatomical and reconstructive features with a quality and quantity sufficient to safely establish a positive correlation between the skeletonized corpse and the missing person.

A identificação humana constitui procedimento de grande importância para os processos instaurados nas várias esferas do Direito, tambémsendo exigida pela sociedade por questões culturais/religiosas. Dentre os processos de identificação pode-se citar a identificação odontolegal,uma metodologia comparativa na qual torna-se necessário que o indivíduo a ser identificado possua as suas particularidades odontológicasregistradas em algum tipo de documento produzido em vida. Neste contexto, as radiografias panorâmicas são exames imaginológicosextrabucais freqüentemente solicitados pelos Cirurgiões-dentistas devido à ampla visualização de estruturas do complexo bucomaxilofacial,que auxiliam na obtenção do diagnóstico e delimitação do plano de tratamento. No presente trabalho, foi relatado um caso de identificaçãohumana utilizando-se uma radiografia panorâmica, produzida há mais de sete anos para subsidiar um planejamento ortodôntico. O confrontoradiográfico foi viabilizado realizando-se uma radiografia panorâmica pós-morte que permitiu a visualização de particularidades anatômicas ereabilitadoras com qualidade e quantidade suficientes para estabelecer uma correlação positiva, com segurança, entre o corpo esqueletizadocomo pertencente à pessoa desaparecida.

Occurrence of maxillary sinus abnormalities detected by cone beam CT in asymptomatic patients.

BACKGROUND: Although cone beam computed tomography (CBCT) images of the maxillofacial region allow the inspection of the entire volume of the maxillary sinus (MS), identifying anatomic variations and abnormalities in the image volume, this is frequently neglected by oral radiologists when interpreting images of areas at a distance from the dentoalveolar region, such as the full anatomical aspect of the MS. The aim of this study was to investigate maxillary sinus abnormalities in asymptomatic patients by using CBCT. METHODS: 1113 CBCT were evaluated by two examiners and identification of abnormalities, the presence of periapical lesions and proximity to the lower sinus wall were recorded. Data were analyzed using descriptive statistics, chi-square tests and Kappa statistics. RESULTS: Abnormalities were diagnosed in 68.2% of cases (kappa = 0.83). There was a significant difference between genders (p < 0.001) and there was no difference in age groups. Mucosal thickening was the most prevalent abnormality (66%), followed by retention cysts (10.1%) and opacification (7.8%). No association was observed between the proximity of periapical lesions and the presence and type of inflammatory abnormalities (p = 0.124). CONCLUSIONS: Abnormalities in maxillary sinus emphasizes how important it is for the dentomaxillofacial radiologist to undertake an interpretation of the whole volume of CBCT images.

Importance of cone beam computed tomography for diagnosis of calcifyingcystic odontogenic tumor associated to odontoma. Report of a case

The calcifying cystic odontogenic tumour (CCOT) is a rare benign cystic neoplasm not infrequently associatedwith odontoma. This report documents a case of CCOT associated with compound odontoma arising in theanterior maxilla in a 25-year-old woman. Conventional radiographs showed a large calcified mass with poorlyvisualized radiolucent margins. The extent and condition of the internal structure of the CCOT associated withodontoma was able to be determined based on radiographic findings from cone beam computed tomography.This advanced image technique proved to be extremely useful in the radiographic assessment of this particularneoplasm of the jawbones (AU)

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Importance of cone beam computed tomography for diagnosis of calcifying cystic odontogenic tumour associated to odontoma. Report of a case.

The calcifying cystic odontogenic tumour (CCOT) is a rare benign cystic neoplasm not infrequently associated with odontoma. This report documents a case of CCOT associated with compound odontoma arising in the anterior maxilla in a 25-year-old woman. Conventional radiographs showed a large calcified mass with poorly visualized radiolucent margins. The extent and condition of the internal structure of the CCOT associated with odontoma was able to be determined based on radiographic findings from cone beam computed tomography. This advanced image technique proved to be extremely useful in the radiographic assessment of this particular neoplasm of the jawbones.