Correlation among alveolar bone assessments provided by CBCT, micro-CT, and 14 T MRI.

OBJECTIVES: The aim of this study was to evaluate bone mineral adipose tissue (BMAT) volume in 21 alveolar bone specimens, as determined by 14 T MRI, and correlate them to the radiodensity values obtained pre-operatively of regions of interest (ROIs) by cone beam computed tomography (CBCT), and to the bone-volume-to-tissue-volume ratio values obtained by micro-CT, the gold-standard for morphometric data collection. METHODS: Partially edentulous patients were submitted to a CBCT scan, and the radiographic bone densities in each ROI were automatically calculated using coDiagnostiX software. Based on the CBCT surgical planning, a CAD/CAM stereolithographic surgical guide was fabricated to retrieve a bone biopsy from the same ROIs scanned preoperatively, and then to orientate the subsequent implant placement. The alveolar bone biopsies were then collected and scanned using the micro-CT and 14 T MRI techniques. Pearson's correlation test was performed to correlate the results obtained using the three different techniques. RESULTS: In the 21 eligible bone specimens (6 females, 15 males), age (mean age 52.9 years), micro-CT, and 14 T MRI variables were found to be normally distributed (p > 0.05). The strongest-and only statistically significant (p < 0.05)-correlation was found between micro-CT and 14 T MRI values (r = 0.943), and the weakest, between 14 T MRI and CBCT values (r = -0.068). CONCLUSIONS: The findings suggest that 14 T MRI can be used to evaluate BMAT as an indirect marker for bone volume, and that CBCT is not a reliable technique to provide accurate bone density values.

Diffusion-weighted magnetic resonance imaging of mandibular bone marrow: do apparent diffusion coefficient values of the cervical vertebrae and mandible correlate with age?

OBJECTIVES: The objective of this investigation was to assess the correlation between the mandible and cervical vertebrae bone marrow apparent diffusion coefficient (ADC), obtained by diffusion-weighted magnetic resonance imaging (DWI), with age; to verify the correlation between ADC values from the mandible and the cervical vertebrae; to describe and assess the differences between ADC values obtained from DWI examinations of distinct mandible areas as well as cervical vertebrae. METHODS: Thirty imaging examinations with DWI for that included the mandible and C1, C2, C3, and C4 vertebrae in the same examination were included. ADC values were collected from 7 distinct areas in the mandible and the cervical vertebrae. Differences between ADC values and non-parametric correlations were performed. RESULTS: A total of 270 regions were assessed. No significant difference was found between ADC values of all areas tested. An inverse correlation was found between C2, C3, and C4 vertebrae ADC values and age. The significant correlation of anatomic area ADC values and age were presented as graphics to verify if the linear trend of ADC values and age are in accordance with the literature CONCLUSIONS: The mandible area that most correlates with the cervical vertebrae, using ADC values, is the posterior trabecular area, below the inferior molars. Also, C2, C3, and C4 vertebrae ADC values inversely correlate with age, which demonstrates the bone qualitative changes in bone composition. ADC values may be useful for the qualitative assessment of bone quality to screen patients at osteoporosis risk.

Estimating bone mineral density using MRI in medicine and dentistry: a literature review.

OBJECTIVES: Studies performed in the medical area have shown that an indirect diagnosis of bone mineral density (BMD) is feasible by assessing the amount of bone marrow fat with non-ionizing magnetic resonance imaging (MRI). In dentistry, radiographic methods are still the most used for alveolar bone diagnosis. The present literature review aimed at addressing the role of MRI in assessing BMD in medicine and dentistry. METHODS: MEDLINE and EMBASE databases were searched for articles published up to 2019. RESULTS: A total of 428 potentially eligible papers were screened. Of these, 397 were excluded after title, abstract and keyword assessment, yielding 31 papers that potentially met the inclusion criteria. Eleven studies were then excluded because their full texts did not discuss the role of MRI in the indirect diagnosis of BMD. As a result, a total of 20 studies were finally identified as eligible for inclusion in this literature review. Most studies found satisfactory accuracy of MRI for indirectly assessing BMD by quantifying bone mineral fat (BMF). However, only one of these studies was on dentistry. CONCLUSION: Within the limitations of this study, the present findings suggest that MRI is accurate to indirectly estimate bone density by assessing BMF, and could be clinically relevant during dental treatment planning.

Full Digital Workflow for Anterior Immediate Implants Using Custom Abutments.

The full digital workflow involves the combination of intraoral and cone beam computerized tomography scans. In the present case report, a second intraoral scan is performed after soft tissue management facilitated by the use of a 3-dimensional-printed interim implant restoration. The new STL file resulting from the second intraoral scan can be associated with the previous STL from the initial intraoral scan. The custom abutment was also digitally designed as an STL file, and no implant scan bodies were required for intraoral scanning.

Correlation between magnetic resonance imaging and cone-beam computed tomography for maxillary sinus graft assessment.

PURPOSE: Little is known regarding the accuracy of clinical magnetic resonance imaging (MRI) protocols with acceptable scan times in sinus graft assessment. The aim of this study was to evaluate the correlations between MRI and cone-beam computed tomographic (CBCT) measurements of maxillary sinus grafts using 2 different clinical MRI imaging protocols. MATERIALS AND METHODS: A total of 15 patients who underwent unilateral sinus lift surgery with biphasic calcium phosphate were included in this study. CBCT, T1-weighted MRI, and T2-weighted MRI scans were taken 6 months after sinus lift surgery. Linear measurements of the maximum height and buccolingual width in coronal images, as well as the maximum anteroposterior depth in sagittal images, were performed by 2 trained observers using CBCT and MRI Digital Imaging and Communication in Medicine files. Microcomputed tomography (micro-CT) was also performed to confirm the presence of bone tissue in the grafted area. Correlations between MRI and CBCT measurements were assessed with the Pearson test. RESULTS: Significant correlations between CBCT and MRI were found for sinus graft height (T1-weighted, r=0.711 and P<0.05; T2-weighted, r=0.713 and P<0.05), buccolingual width (T1-weighted, r=0.892 and P<0.05; T2-weighted, r=0.956 and P<0.05), and anteroposterior depth (T1-weighted, r=0.731 and P<0.05; T2-weighted, r=0.873 and P<0.05). The presence of bone tissue in the grafted areas was confirmed via micro-CT. CONCLUSION: Both MRI pulse sequences tested can be used for sinus graft measurements, as strong correlations with CBCT were found. However, correlations between T2-weighted MRI and CBCT were slightly higher than those between T1-weighted MRI and CBCT.

Full digital workflow for crown lengthening by using a single surgical guide.

A technique using a digital workflow for performing crown lengthening by using a free software program is presented to digitally design a single surgical guide. The technique consists of obtaining standard tessellation language (STL) files from intraoral scans from a digital design of the new tooth shape and from a cone beam computed tomography (CBCT) scan, after which Digital Imaging and Communications in Medicine (DICOM) files are converted to the STL format. These files are then superimposed and used for surgical planning of the crown-lengthening procedure. The main component of the surgical guide is a labial upper band representing the biological width measurement based on the predicted digitally designed future gingival margin position. Accordingly, the lower edge of the band indicates the level of the main marginal incision, whereas the top of the band indicates the level where the alveolar bone crest must be repositioned by alveolotomy during the surgical crown-lengthening procedure. By performing an adequate diagnosis of the potential restorative outcome, the new position of the gingival margin and the crown shape can be predicted, and whether osteoplasty is needed can be determined.

Histologic Evaluation of Early Bone Regeneration Treated with Simvastatin Associated with Low-Level Laser Therapy.

PURPOSE: This histologic study aimed at assessing bone healing after treatment with simvastatin in association with low-level laser therapy (LLLT). METHODS: Twenty-four male rats (Wistar) were submitted to surgery to create a bone defect of 5 mm in diameter in the parietal bone. These rats were randomly and equally divided into four treatment groups (n = 6): control (C), in which no treatment was performed; simvastatin (SIM), in which rats received daily subcutaneous doses of 2.5 mg/kg of simvastatin; LLLT, which was daily applied to the bone defect; and SIM-LLLT, in which both SIM and LLLT were daily applied. All laser irradiations were carried out with a 830-nm infrared diode laser (GaAlAs) with maximum output of 100 mW and a dose of 4 J, totaling 16 J per session. Rats were euthanized on the 12th postoperative day. Formalin-fixed paraffin-embedded bone samples were obtained and stained with hematoxylin-eosin (HE) and toluidine blue for optical microscope analysis. Degree of inflammation, new vascular formation, tissue repair, and osteoblastic activity were assessed. RESULTS: Categorical analysis of the histologic slides revealed newly formed bone reaching the center of the surgical wound in two animals from the SIM group, two from the LLLT group, and three from the SIM-LLLT group. Greater new bone formation and a lower degree of inflammation were observed in the animals that had bone neoformation at the center of the defect, especially in the LLLT and SIM-LLLT groups. SIM and C groups presented greater angiogenesis than LLLT and SIM-LLLT. SIMLLLT therapy showed a statistically significant reduction in the degree of inflammation when compared to the control group (P < .05). CONCLUSION: Within the limitations of this study, the present results suggest that a combination of simvastatin and low-level laser therapy may stimulate better bone formation.

Comparison of conventional imaging techniques and CBCT for periodontal evaluation: A systematic review.

PURPOSE: This study aimed to carry out a systematic review of studies in the literature comparing conventional imaging techniques with cone-beam computed tomography in terms of the role of these techniques for assessing any of the following periodontal conditions and parameters: infrabony defects, furcation involvement, height of the alveolar bone crest, and the periodontal ligament space. MATERIALS AND METHODS: Interventional and observational studies comparing conventional imaging techniques with cone-beam computed tomography were considered eligible for inclusion. The MEDLINE and Embase databases were searched for articles published through 2017. The PRISMA statement was followed during data assessment and extraction. RESULTS: The search strategy yielded 351 publications. An initial screening of the publications was performed using abstracts and key words, and after the application of exclusion criteria, 13 studies were finally identified as eligible for review. CONCLUSION: These studies revealed cone-beam computed tomography to be the best imaging technique to assess infrabony defects, furcation lesions, the height of the alveolar bone crest, and the periodontal ligament space.

Bone mineral density and mandibular osteoporotic alterations in type 2 diabetes / Densidade mineral óssea e alterações osteoporóticas na mandíbula em pacientes diabéticos do tipo 2

Objective: To assess the influence of type 2 diabetes on bone mineral density in a group of type 2 diabetic patients, in comparison with non-diabetic patients. Additionally, to evaluate the correlation between mandibular cortical index and bone mineral density. Material and Methods: 48 patients (24 diabetics and 24 non-diabetics) referred for femur and spine densitometry and panoramic radiograph examination were included in this study. Patients were diagnosed based on densitometric results of the total femur and total spine. All panoramic radiomorphometric measurements were performed by 3 observers. Differences in T and Z-scores between both groups were evaluated with Mann-Whitney test and non-parametric correlations between mandibular cortical index and T/Z-scores were carried out with Spearman's test. Results: Median T and Z-scores for total femur and total spine presented no statistical significant difference between diabetic and nondiabetic patients. In addition, only diabetics total femur and non-diabetics total spine T-scores were significantly correlated with mandibular cortical index. Conclusion: The present results suggest that type 2 diabetic patients have similar Z and T-scores in femur and spine when compared to non-diabetic patients. Mandibular cortical index, assessed on panoramic radiographs is inversely correlated with femur densitometry results in diabetics and spine bone mineral density in nondiabetic patients. (AU)

Objetivo: avaliar a influência do diabetes tipo 2 na densidade mineral óssea em um grupo de pacientes diabéticos do tipo 2, em comparação com pacientes não diabéticos. Adicionalmente, analisar a correlação entre o índice cortical mandibular e a densidade mineral óssea. Material e Métodos: 48 pacientes (24 diabéticos e 24 não diabéticos) que realizaram densitometria óssea de fêmur e coluna vertebral e exame radiográfico panorâmico foram incluídos neste estudo. Os pacientes foram diagnosticados com base nos resultados densitométricos do fêmur total e da coluna total. Por meio das radiografias panorâmicas, 3 observadores avaliaram o índice da cortical mandibular. Diferenças em T e Z scores entre os dois grupos foram avaliadas com o teste de MannWhitney e as correlações não paramétricas entre o índice cortical mandibular e os scores da densitometria foram verificadas por meio do teste de Spearman. Resultados: A mediana dos T e Z-scores para fêmur total e coluna total não apresentaram diferença estatisticamente significante entre diabéticos e não-diabéticos. Além disso, houve correlação significativa com o índice da cortical mandibular somente os T-scores de fêmur total do grupo de pacientes diabéticos e de coluna total dos paciente não-diabéticos. Conclusão: Os resultados deste estudo sugerem que pacientes diabéticos tipo 2 tem densidade mineral óssea aferida por meio de densitometria óssea do fêmur e coluna total semelhantes aos não-diabéticos. O índice cortical mandibular, avaliado em radiografias panorâmicas, foi inversamente correlacionado com os resultados da densitometria do fêmur em pacientes diabéticos e da densitometria de coluna total de pacientes não diabéticos. (AU)

Relato de caso clínico: tumor odontogênico queratocístico na primeira infância / Case report: keratocystic odontogenic tumor in early childhood

Em 2005, o queratocisto odontogênico foi renomeado e reclassificado para tumor odontogênico queratocístico pela Organização Mundial de Saúde. Seu comportamento agressivo e invasivo, sua elevada taxa de recidiva pós-operatória e novas descobertas moleculares possibilitaram esta reclassificação. Neste artigo pretendemos recordar alguns conceitos desta lesão bem como discutir alguns parâmetros de imagem destacando um caso clínico atípico desta lesão. Discutindo de que modo as novas tecnologias de diagnóstico por imagem auxiliam o Cirurgião-Dentista no planejamento terapêutico e no diagnóstico deste tipo de lesão.

In 2005 the Keratocyst Odontogenic was renamed and reclassified to Keratocystic Odontogenic Tumor by the World Health Organization. His aggressive and invasive behavior, its high postoperative recurrence rate and new molecular discoveries made possible this reclassification. This article aims to recall some concepts of this injury as well as discuss some image parameters highlighting an atypical clinical case of injury. Discussing how new technologies diagnostic imaging helps the dentist surgeon in planning and diagnosis of this type of lesion.

Estudo da atual utilização da TCFC pelos Cirurgiões-Dentistas nas diversas especialidades / Study of current use of Cone-Beam CT by dental surgeons in the various specialties

Objetivo: Determinar, dentre os profissionais de Odontologia, o grau de formação e informação quanto ao uso da tomografia computadorizada tipo cone-beam, assim como quantificar e discriminar o uso desta ferramenta diagnóstica no cotidiano das especialidades. Materiais e métodos: Profissionais cursando algum tipo de especialização tiveram que responder a um questionário de respostas certo/errado, que continha parâmetros sobre as indicações do uso da tomografia computadorizada na Odontologia, assim como perguntas que permitiram o levantamento de informações acerca desta ferramenta diagnóstica no tocante a influência do custo do procedimento, necessidade de treinamento específico para interpretação e necessidade de investimento por parte do profissional clínico. Resultados: Pudemos observar que a indicação da técnica não está totalmente esclarecida para muitos Cirurgiões-Dentistas. A porcentagem de desconhecimento foi significativa (27%), por se tratar de radiação ionizante, que pode causar riscos estocásticos e deletérios. Pudemos observar em nossos resultados que existe um embasamento geral da técnica, pois à medida que especialistas de uma certa área acertaram questões correspondentes a outras especialidades, notamos a ocorrência de equívocos de conceitos quando eram questionados sobre o protocolo de uso em sua própria área de conhecimento. Conclusão: A divulgação dos dados obtidos será de grande valia para o clínico geral, bem como para os especialistas, no intuito de reduzir a dose de exposição desnecessária quando da indicação da técnica. A necessidade de aprimorar o conhecimento será sempre necessária, para que não tenhamos apenas o conhecimento geral, mas o específico para a área de atuação de cada um.

Objective: To determine, among dental professionals, the degree of training and information regarding the use of CBCT, as well as to quantify and discriminate the use of this diagnostic tool in specialties daily basis. Materials and methods: Professionals attending specialization courses had to answer a right/wrong answers questionnaire containing parameters of indications for the use of computed tomography in dentistry. Beyond that, they had to answer questions that allowed the collection of information about this diagnostic tool regarding the influence of the cost of the procedure, the need for specific training in the interpretation and need for investment by the clinical professional. Results: We observed that the technique is not entirely clear for many dentists. The percentage of unawareness was significant (27%) considering it is about an ionizing radiation, which can cause deleterious and stochastic risks. We observed in our results that there is a general grounding of the technique, because on the one hand experts of a determined area showed a certain knowledge of other specialties, on the other hand we verified there were misunderstandings of concepts when questioned about the protocol used in their own area of knowledge. Conclusion: The release of the data obtained will be of great value to the general practitioner as well as to specialists in order to reduce the amount of unnecessary exposure in the indication of the technique. Improve knowledge will always be necessary so we will not only have general knowledge, but the specific one to the area of each dentistry professional.