Are Radiographic Changes in the Mandibular Canal Associated With Bone Mineral Density?

BACKGROUND: Osteoporosis, highly prevalent among postmenopausal women, significantly reduces bone density and increases the risk of fractures. Cortical bone, which constitutes the largest calcium deposit in the human skeleton, is primarily affected in various conditions, including osteoporosis. Due to its visibility in panoramic radiography, the cortical area of the mandibular canal could be valuable in assessing decreases in bone mineral density (BMD). PURPOSE: The study aimed to characterize and compare changes in the cortices of the mandibular canal between normal, osteopenic, and osteoporotic postmenopausal women. STUDY DESIGN, SETTING, SAMPLE: Our cross-sectional study analyzed postmenopausal patients. We included only patients with panoramic radiographs with good quality and who underwent osteoporosis risk assessment by dual-energy x-ray absorptiometry (DXA). INDEPENDENT VARIABLE: BMD was measured by DXA at 3 sites (spine, femur, and forearm) and used to classify the patients into normal, osteopenic, or osteoporotic. This classification remained consistent across all measurement sites. MAIN OUTCOME VARIABLE: The main outcome variable was BMD of the mandibular canal cortices measured using black pixel intensity. COVARIATES: Demographic covariates, including age, weight, height, and BMD, were assessed. ANALYSES: One-way analysis of variance between groups considering a P < .05. The relationship between covariates and dependent variables was assessed using the Pearson correlation test. RESULTS: The sample comprised 52 postmenopausal women aged more than 40 years (mean age 61 ± 10 years), 26 (50%) normal, 18 (35%) osteopenic, and 8 (15%) osteoporotic. Significant differences were observed in the percentage of black pixels in the mandibular ramus between the groups. In this region, the average percentage of black pixels was 3.19% (± 0.65) for the normal group, 2.78% (± 0.65) for the osteopenia group, and 2.35% (± 0.65) for the osteoporosis group (P = .015). No significant differences were found in other mandibular regions. CONCLUSION AND RELEVANCE: Our findings demonstrate an association between BMD assessed in the mandibular canal cortex and the presence of osteoporosis as determined by DXA. While the observed differences in black pixel percentages in the mandibular ramus are minor, they are statistically significant, suggesting that panoramic radiography may serve as an adjunctive tool for osteoporosis screening.

Assessment of the correlation between mandibular radiomorphometric patterns and dual-energy X-ray absorptiometry measurements for screening bone mineral density.

The objective of this study was to investigate the correlation between scores for femoral and lumbar spine bone mineral density (dual-energy X-ray absorptiometry [DXA]) and visual, qualitative mandibular bone pattern assess¬ments (mandibular cortical index, trabecular bone pattern, and visual mandibular cortical width) as well as age and body mass index. Three trained observers evaluated 200 panoramic radiographs and 200 femoral and lumbar spine DXA measurements from 100 male and 100 female participants. The κ test showed an acceptable agreement among observers (0.73; P = 0.003). The Shapiro-Wilk test revealed that the variables were not normally distributed, so the Spearman correlation test was used. The mean age of the sample was 60.7 (13.9) years, and 86.0% of the patients were White. There were inverse correlations between the mandibular cortical index and the spine T-score in men, women, and the total sample as well as between the spine Z-score in the total sample. An inverse correlation was observed between the trabecular bone pattern and the spine T- and Z-scores in women and the total sample. The results also showed inverse correlations between the visual mandibular cortical width and all parameters analyzed in men, women, and the total sample except for the femur T-score and spine T- and Z-scores in men. Body mass index was correlated with all DXA parameters. Age was inversely correlated with femur T-scores in men and women but not with spine DXA values in men. The results suggest that qualitative assessments of radiomorphometric patterns on panoramic radiographs correlate with DXA values and therefore are suitable for screening patients at risk of developing low bone mineral density.

Deep learning for automatic mandible segmentation on dental panoramic x-ray images.

Many studies in the last decades have correlated mandible bone structure with systemic diseases like osteoporosis. Mandible segmentation, as well as segmentation of other oral structures, is an essential step in studies that correlate oral structures' conditions with systemic diseases in general. However, manual mandible segmentation is a time-consuming and training-required task that suffers from inter and intra-user variability. Further, the dental panoramic x-ray image (PAN), the most used image in oral studies, contains overlapping of many structures and lacks contrast on structures' interface. Those facts make both manual and automatic mandible segmentation a challenge. In the present study, we propose a precise and robust set of deep learning-based algorithms for automatic mandible segmentation (AMS) on PAN images. Two datasets were considered. An in-house image dataset with 393 image/segmentation pairs was prepared using image data of 321 image patient data and the corresponding manual segmentation performed by an experienced specialist. Additionally, a publicly available third-party image dataset (TPD) composed of 116 image/segmentation pairs was used to train the models. Four deep learning models were trained using U-Net and HRNet architectures with and without data augmentation. An additional morphological refinement routine was proposed to enhance the models' prediction. An ensemble model was proposed combining the four best-trained segmentation models. The ensemble model with morphological refinement achieved the highest scores on the test set (98.27%, 97.60%, 97.18%, ACC, DICE, and IoU respectively), with the other models scoring above 95% in all performance metrics on the test set. The present study achieved the highest ranked performance considering all the previously published results on AMS for PAN images. Additionally, those are the most robust results achieved since it was performed over an image set with considerable gender representativeness, a wide age range, a large variety of oral conditions, and images from different imaging scans.

Head and neck radiotherapy-induced changes in dentomaxillofacial structures detected on panoramic radiographs: A systematic review.

PURPOSE: This study aimed to summarize the impact of neck and head radiation treatment on maxillofacial structures detected on panoramic radiographs. MATERIALS AND METHODS: In this systematic review, the authors searched PubMed Central, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar for original research studies up to February 2020 that included the following Medical Subject Headings keywords: words related to "radiotherapy" and synonyms combined with keywords related to "panoramic radiography" and "oral diagnosis" and synonyms. Only original studies in English that investigated the maxillofacial effects of radiotherapy via panoramic radiographs were included. The quality of the selected manuscripts was evaluated by assessing the risk of bias using Cochrane's ROBINS-I tool for non-randomized studies. RESULTS: Thirty-three studies were eligible and included in this review. The main objectives pertained to the assessment of the effects of radiation on maxillofacial structures, including bone architecture alterations, periodontal space widening, teeth development abnormalities, osteoradionecrosis, and implant bone loss. The number of participants evaluated ranged from 8 to 176. CONCLUSION: The interaction between ionizing radiation and maxillofacial structures results in hazard to the tissues involved, particularly the bone tissue, periosteum, connective tissue of the mucosa, and endothelium. Hard tissue changes due to radiation therapy can be detected on panoramic radiographs.

Maxillofacial manifestations of Proteus syndrome: a systematic review with a case report.

OBJECTIVES: Proteus syndrome (PS) is an extremely rare disorder with asymmetric and disproportionate bone overgrowth. Craniofacial abnormalities in PS are less frequent than skeletal abnormalities. Although there are recognized oral and maxillofacial manifestations of PS, few case reports describing these manifestations are available. Thus, the objective of this systematic review and case report is to describe oral and maxillofacial manifestations of PS and to report a PS case. METHODS: A 31-year-old male presented with restricted mouth opening and pain during mastication. A panoramic radiograph and an occlusal radiograph were obtained. Reports with relevant keywords were assessed. Data were summarized and demonstrated using a critical appraisal checklist for case reports. RESULTS: The panoramic radiograph demonstrated unilateral overgrowth of the mandible, impacted teeth, and deciduous prolonged retention. Thirteen PS case reports were identified. CONCLUSIONS: Proteus syndrome oral and maxillofacial manifestations may include dental agenesis, impacted teeth, malocclusion, asymmetric dental growth and maturation, frontal line displacement, asymmetric tongue enlargement, mandibular hemihypertrophy and asymmetry, presence of exostoses/hyperostosis, degenerative changes in the temporomandibular joint, alterations of maxillary and mandibular vertical and/or horizontal growth, and enlargement of mandibular canal and foramen. The PROSPERO systematic review registration number is CRD42019140942.

Bone mineral density and mandibular osteoporotic alterations in panoramic radiographs: Correlation by peripheral bone densitometry in men.

AIM: Mandibular cortical index has proven to be inversely correlated to bone densitometry; however, trabecular bone pattern has not been widely studied. Thus, the main objectives of this study were: (1) to analyze the correlations between three different sites of peripheral dual-energy X-ray absorptiometry with the mandibular cortical index and the trabecular bone pattern classification; (2) to assess the correlation between the mandibular cortical index and the trabecular bone pattern; (3) to evaluate the diagnostic accuracy of the mandibular cortical index and the trabecular bone pattern using panoramic radiographs in a sample of Brazilian men. Additionally, peripheral dual-energy X-ray absorptiometry findings in men were described. MATERIALS AND METHODS: There are about 44 men who had previously undergone panoramic radiography and bone densitometry were evaluated. Mandibular cortical index and trabecular bone pattern classifications were performed. The median T-scores of the men were analyzed. Spearman's test was performed to assess correlations. RESULTS: An inverse correlation was found between mandibular cortical index and proximal bone densitometry site. No correlation was found between mandibular cortical index and trabecular bone pattern or between peripheral densitometry and trabecular bone pattern. Greater accuracy was observed in mandibular cortical index when compared to trabecular bone pattern. Mandibular cortical index evaluations by panoramic radiographs are a useful screening tool for low bone mineral density, but trabecular bone pattern cannot be applied to screen patients for osteoporosis risk. Mandibular cortical index has an inverse correlation with proximal sites of forearm densitometry.

Comparison between different cone-beam computed tomography devices in the detection of mechanically simulated peri-implant bone defects.

PURPOSE: This study compared 2 cone-beam computed tomography (CBCT) systems in the detection of mechanically simulated peri-implant buccal bone defects in dry human mandibles. MATERIALS AND METHODS: Twenty-four implants were placed in 7 dry human mandibles. Peri-implant bone defects were created in the buccal plates of 16 implants using spherical burs. All mandibles were scanned using 2 CBCT systems with their commonly used acquisition protocols: i-CAT Gendex CB-500 (Imaging Sciences, Hatfield, PA, USA; field of view [FOV], 8 cm×8 cm; voxel size, 0.125 mm; 120 kVp; 5 mA; 23 s) and Orthopantomograph OP300 (Intrumentarium, Tuusula, Finland; FOV, 6 cm×8 cm; voxel size, 0.085 mm; 90 kVp; 6.3 mA; 13 s). Two oral and maxillofacial radiologists assessed the CBCT images for the presence of a defect and measured the depth of the bone defects. Diagnostic performance was compared in terms of the area under the curve (AUC), accuracy, sensitivity, specificity, and intraclass correlation coefficient. RESULTS: High intraobserver and interobserver agreement was found (P<0.05). The OP300 showed slightly better diagnostic performance and higher detection rates than the CB-500 (AUC, 0.56±0.03), with a mean accuracy of 75.0%, sensitivity of 81.2%, and specificity of 62.5%. Higher contrast was observed with the CB-500, whereas the OP300 formed more artifacts. CONCLUSION: Within the limitations of this study, the present results suggest that the choice of CBCT systems with their respective commonly used acquisition protocols does not significantly affect diagnostic performance in detecting and measuring buccal peri-implant bone loss.

Gardner syndrome imaging features in plain radiographs and computed tomography: a case report / Síndrome de Gardner: Características imaginológicas por meio da radiografia convencional e tomografia computedorizada

Gardner syndrome (GS) is a genetic disease with high penetration characterized by a signal triad of colonic polyposis, multiple osteomas and mesenchymal tumors in the soft tissues and skin. The colonic polyposis is associated to the development of malignant disease. Patients may also present maxillomandibular alterations such as impacted teeth, supernumerary teeth, congenital missing teeth and odontomas. Bone lesions and maxillomandibular alterations usually precedes the gastrointestinal alterations; hence dentists should be aware of GS syndrome main radiographic signals, in order to detect the disease and proper referred the patient to medical treatment and surveillance. Thus, in this report, it is described a case of GS in a male patient, as well as discussed GS features.(AU)

A síndrome de Gardner (GS) é uma doença genética caracterizada pela seguinte tríade: polipose colônica, múltiplos osteomas e tumores mesenquimais em tecidos moles e pele. A polipose colônica está associada ao desenvolvimento de tumores malignos. Os pacientes também podem apresentar alterações maxilomandibulares, como dentes impactados, dentes supranumerários, agenesia congênita e odontomas. Lesões ósseas e alterações maxilomandibulares geralmente precedem as alterações gastrointestinais; portanto, os dentistas devem estar cientes dos principais sinais imaginológicos da GS, a fim de detectar a doença e encaminhar adequadamente o paciente para tratamento. Neste relato de caso é descrito um caso de GS em um paciente do gênero masculino, além de discutir as características da GS.(AU)

Effects of latex membrane on guided regeneration of long bones.

Natural latex extracted from Hevea brasiliensis is one of the materials pointed out as potential tissue regenerators. The use of latex-based membranes in bone regeneration might be an alternative to stimulate bone formation. The aim of this study was to evaluate the effects of latex membranes in guided bone regeneration of defects produced in long bones of rats. Sixty rats were equally divided into latex and control groups, and each group was subdivided into two subgroups according to treatment duration of 1 and 4 weeks. Bone defects with 2.5 mm in diameter were surgically made in the left tibia. In the animals of the latex group, a latex membrane was placed over the bone defect. The samples underwent quantitative histological analysis of bone formation and collagen matrix, immunohistochemical analysis of osteogenic protein markers, assessment of bone mechanical properties and bone densitometry, and radiological assessment. The osteocalcin immunostaining data were submitted to the generalized linear model test with two independent factors. For the other data, the multivariate ANOVA with two independent factors was performed. The use of the latex membrane significantly improved (p < 0.005) the volume of newly formed bone, collagen type I matrix, expression of osteopontin, and bone stiffness, both in the early and late stages of regeneration. In conclusion, the latex membrane was able to promote bone regeneration in long bones.

Idiopathic exostosis: rarity on maxillary sinus

Introduction: Exostoses in the paranasal sinuses have been reported in a greater number in the dental radiological literature, despite the extensive citation in the otorhinolaryngology literature. Objective: This case report was a rare idiopathic expression that grew in the maxillary sinus. Case report: A 68-year-old black patient, BGS, followed up by the Odontology Service of Cancer Hospital for treating oral lesions (Mucositis) and other conditions resulting from radiation therapy and hormone therapy (Tamoxifen), presented malignant neoplasm at the right breast in 2015; an exostosis biopsy was not performed, since the patient is being treated and followed up by the hospital service. Panoramic radiography and clinical examination were performed. By analyzing the tests, it was possible to notice an image with double radiodensity, more radiopaque in the external portion and less radiopaque in the internal portion, with an aspect of trabecular bone, circumscribed, unilocular, in the region of pedunculated premolar, inside the left maxillary sinus. In order to have a better assessment and diagnostic hypothesis of the case, a CT scan was performed, a tool was applied to measure the density of the profile of the lesion, thus evidencing that the supposed injury invaginates to the interior of the maxillary sinus and had bone density similar to the alveolar crest bone. Conclusion: Simultaneously to other lesions, exostoses are benign lesions, present low aggression and rare symptomatology; exeresis is indicated only when it prevents functioning, or for aesthetics reasons, or when it is not possible to make prostheses. Many cases are incidentally diagnosed from routine radiographic review in medical or dental offices and should be followed up for analysis and verification of their growth.

Introdução: Exostoses nos seios paranasais têm sido muito mais relatados na literatura radiológica odontológica, apesar da extensa citação na literatura otorrinolaringológica. Objetivo: Neste relato de caso, encontramos uma exostose idiopática rara, que cresceu no seio maxilar. Relato de caso: Paciente negra de 68 anos, BGS, acompanhada pelo Serviço de Odontologia do Hospital do Câncer para tratamento de lesões orais (mucosite) e outras condições decorrentes da radioterapia e terapia hormonal (Tamoxifeno), apresentou neoplasia maligna da mama direita em 2015. Não foi realizada biopsia da exostose, pois a paciente está em tratamento e está sendo acompanhada pelo serviço do hospital. Realizaram-se radiografia panorâmica e exame clínico. Ao examinar os exames, foi possível notar uma imagem com dupla radiodensidade, mais radiopaca numa parte externa e menos radiopaca na parte interna, com aspecto de osso trabecular, circunscrito, unilocular, na região do ré-molar pediculado, no interior do seio maxilar esquerdo. Para melhor avaliação e hipótese diagnóstica, foi realizada uma tomografia computadorizada, aplicou-se uma ferramenta para mensuração da densidade do perfil da lesão, evidenciando-se que a suposta lesão invagina para o interior do seio maxilar e tinha densidade óssea semelhante ao osso da crista alveolar. Conclusão: Simultaneamente a outras lesões, as exostoses são lesões benignas, apresentam baixa agressividade e rara sintomatologia, sendo indicada exérese somente quando acomete a função, ou por motivos estéticos, ou quando não é possível a confecção de próteses. Muitos dos casos são diagnosticados de modo incidental e a partir de exames radiográficos de rotina em consultórios médicos ou odontológicos e devem ser acompanhados para análise e verificação de seu crescimento.

Evaluation and Correlation between craniofacial bone densities and C1 and C2 cervical vertebrae using multislice computed tomography / Avaliação e Correlação entre as densidades ósseas craniofaciais e vértebras cervicais C1 e C2 por meio de tomografia computadorizada multislice

Objective: To evaluate the use of computed tomography (CT) as an osteoporosis screening tool, evaluating the relation between the bone mineral density (BMD) from maxilla and mandible with the cervical vertebrae, using the Hounsfield units (HU). Material and Methods: It was included in this study a convenience sample of 118 multislice CT examinations from patients who underwent maxilla, mandible and cervical vertebrae (C1 and C2) simultaneously scans. For each patient, the following regions on both sides of head CT scans were assessed in sagittal slice: above maxillary central and lateral incisors apexes; maxillary tuberosity; mandible head; mandible body endosteum; mandible body trabeculae and vertebrae C1 and C2. HU were measured in each area using a 0.5 cm region of interest (ROI) positioned in the center of the slice. Results: It was verified that there is a correlation between the BMD of the C1 and C2 vertebrae and the anterior region of the maxilla. It was not found correlation between the vertebrae, C1 and C2, and the other structures analyzed. Conclusions: This study showed that this method can be a good screening tool to diagnosis of osteoporosis, when evaluated the correlation between C1 and C2 vertebrae and anterior region of maxilla. More studies are necessary to evaluate the possibility of using CT as an osteoporosis screening tool. (AU)

Objetivos: Avaliar o uso da tomografia computadorizada como ferramenta de rastreamento da osteoporose, avaliando a relação entre a densidade mineral óssea da maxila e mandíbula com as vértebras cervicais, utilizando as unidades de Hounsfield. Material e métodos: Neste estudo foram incluidos uma amostra de 118 pacientes submetidos à exames de tomografia computadorizada multislice que apresentavam as estruturas anatomicas da maxila, mandibula e as vértebras cervicais (C1 e C2) simultaneamente. Para cada paciente, as seguintes regiões dos dois lados da tomografia computadorizada da cabeça foram avaliadas em corte sagital: acima dos ápices dos incisivos centrais e laterais superiores; tuberosidade maxilar; cabeça da mandíbula; endósteo do corpo da mandíbula; trabéculas do corpo da mandíbula e vértebras C1 e C2. As unidades de Hounsfield foram medidas em cada área usando uma região de interesse de 0,5 cm (ROI) posicionada no centro do corte. Resultados: Verificou-se uma correlação positiva entre a densidade mineral óssea das vértebras C1 e C2 e a região anterior da maxila. Não foram encontradas correlação entre as vértebras C1 e C2 e as demais estruturas analisadas. Conclusão: Este estudo mostrou que esse método pode ser uma ferramenta de triagem para o diagnóstico de osteoporose, quando avaliada a correlação entre as vértebras C1 e C2 e a região anterior da maxila. Mais estudos são necessários para avaliar a possibilidade do uso da tomografia computadorizada como ferramenta de rastreamento da osteoporose. (AU)

Literature Review: Dental Aspects in Gaucher Disease / Revisión de la Literatura: Aspectos Dentales en la Enfermedad de Gaucher

SUMMARY: Knowledge about Gaucher disease, characteristics, clinical and radiographic alterations, demonstrate the importance of using anamnesis, laboratory tests and radiological images, among these dental analysis and images, making possible the early detection in the oral manifestations and the success in the control and treatment of the disease.

RESUMEN: El conocimiento sobre la enfermedad de Gaucher, características, alteraciones clínicas y radiográficas, demuestra la importancia de utilizar la anamnesis, los exámenes de laboratorio e imágenes radiológicas, entre ellas las odontológicas, posibilitando la detección precoz de las manifestaciones orales, y el éxito en el control y tratamiento de la enfermedad.

Computed Tomographic Artifacts in Maxillofacial Surgery.

OBJECTIVES: The present study aimed to present 4 cases and to undertake a systematic review on the current knowledge of the impact of cone beam computed tomographic (CBCT) artifacts on oral and maxillofacial surgical planning and follow-up. METHODS: The MEDLINE (PubMed) database was searched for the period from February 2004 to February 2017, for studies on the impact of CBCT artifacts on surgical planning of oral and maxillofacial surgeries. The PRISMA statement was followed during data assessment and extraction. As a result, data extraction included information regarding: the use of CBCT to plan or follow-up oral and maxillofacial surgeries, presence and type identification of a CBCT artifact, and details on the impact of artifacts on image quality and/or surgical planning. Four cases were selected to illustrate the topic. RESULTS: The search strategy yielded 408 publications in MEDLINE (PubMed). An initial screening of the publications was performed using abstracts and key words. After application of exclusion criteria, a total of 11 studies were finally identified as eligible to be discussed. Studies revealed 3 main types of artifact: beam hardening, streak, and motion artifacts. Most of the studies suggest that artifacts significantly affect oral and maxillofacial surgical planning and follow-up, despite of allowing for identification of metal projectiles in cases of maxillofacial trauma. CONCLUSION: CBCT artifacts have a significant impact on oral and maxillofacial surgical planning and follow-up.

Validation of cone-beam computed tomography as a predictor of osteoporosis using the Klemetti classification.

This study aimed at evaluating the validity of cone-beam computed tomography (CBCT) for assessing mandibular bone quality using the Klemetti classification. The morphology of the endosteal mandibular cortex of 30 (60 hemi-mandibles) postmenopausal women between the ages of 45 and 80 years was evaluated based on the Klemetti classification in panoramic radiographs used as reference images. Afterwards, panoramic reconstruction and cross-sectional slices of CBCT examinations of these patients were analyzed and categorized according to the same classification. All the images were assessed by two oral radiologists. The McNemar-Bowker test compared the agreement between the CBCT images and the reference images. No differences were found between the diagnostic results based on panoramic radiography and panoramic reconstruction. However, the mean scores for the cross-sectional evaluation were higher, and the results, statistically different from the others. Based on the disagreement found between the panoramic radiographs and the CBCT cross-sectional slices, the Klemetti classification is not an adequate means of assessing bone quality with CBCT. On the other hand, the higher values found for the cross-sectional slices could be associated with better visibility on the CBCT images.

Diagnostic performance of fractal dimension and radiomorphometric indices from digital panoramic radiographs for screening low bone mineral density

A number of panoramic radiographic measurements have been associated with osteoporotic alterations. However, little is known about the differences in sensitivity and specificity among these measurements for screening low bone mineral density (BMD). Aim: To correlate and compare precision, sensitivity and specificity of panoramic radiomorphometric indices and fractal dimension (FD) for screening low BMD (i.e. osteopenia and osteoporosis). Methods: Sixty-eight female patients (42.78±15.59 years) were included in this study. Body mass index (BMI), mandibular cortical index (MCI), mandibular cortical width (MCW), FD and connectivity (C) were assessed. Low BMD was diagnosed by peripheral dual-energy X-ray absorptiometry (p-DXA). Non-parametric correlations were assessed among all variables. In addition, sensitivity and specificity of MCI, MCW and FD were estimated for screening low BMD. Results: Significant correlation was found between FD and BMI (p=0.013; r=0.269). In addition, FD was the most sensitive method for screening low BMD (70.8%, p=0.001). FD and MCI presented a significant and relatively high sensitivity, whereas MCW presented a high specificity for screening low systemic BMD Conclusions: Among the analyzed methods, FD and MCI offer a significant and relatively high sensitivity, whereas MCW offers a high specificity for screening low BMD (Au)

Fusion or gemination? An unusual mandibular second molar.

Fusion and gemination is not an uncommon finding and affected most primary dentition and the permanent maxillary incisors. These changes can develop a series of complication. A 11-year-old male presented radiography finding: an unusual mandibular second molar. A well-documented case brings a challenge for radiologists classify between fusion and gemination. In conclusion, this alteration although common in other regions, there are no case in the literature involving "second and third" molar.

Validation of cone-beam computed tomography as a predictor of osteoporosis using the Klemetti classification

Abstract This study aimed at evaluating the validity of cone-beam computed tomography (CBCT) for assessing mandibular bone quality using the Klemetti classification. The morphology of the endosteal mandibular cortex of 30 (60 hemi-mandibles) postmenopausal women between the ages of 45 and 80 years was evaluated based on the Klemetti classification in panoramic radiographs used as reference images. Afterwards, panoramic reconstruction and cross-sectional slices of CBCT examinations of these patients were analyzed and categorized according to the same classification. All the images were assessed by two oral radiologists. The McNemar-Bowker test compared the agreement between the CBCT images and the reference images. No differences were found between the diagnostic results based on panoramic radiography and panoramic reconstruction. However, the mean scores for the cross-sectional evaluation were higher, and the results, statistically different from the others. Based on the disagreement found between the panoramic radiographs and the CBCT cross-sectional slices, the Klemetti classification is not an adequate means of assessing bone quality with CBCT. On the other hand, the higher values found for the cross-sectional slices could be associated with better visibility on the CBCT images.

Comparación de dos métodos radiológicos para evaluación de densidad ósea en mujeres posmenopáusica / Comparison of two radiological methods for evaluation of bone density in postmenopausal women

Debido a la importancia del diagnóstico precoz de osteoporosis, fue objeto de este estudio realizar la comparación de dos métodos radiológicos convencionales para la evaluación de la densidad ósea en mujeres posmenopáusicas. Fueron seleccionadas imágenes de radiografía panorámica y de radiografía carpal, correspondiente a 68 pacientes de sexo femenino, con edades comprendidas entre los 49 y 80 años de edad, realizadas en la Clínica de Radiología Odontológica, para evaluación previa a la colocación de implantes. Para la interpretación de la densidad ósea en la mandíbula a través de las radiografías panorámicas fue utilizado el método del espesor cortical mandibular (PMI). Para la evaluación de las imágenes radiológicas obtenidas por la radiografía carpal, fue aplicado el método de la radiogrametría. Se concluye que existe correlación entre la presencia de una baja densidad ósea a nivel mandibular observada en la radiografía panorámica en las pacientes de la muestra, con la baja densidad ósea presentada en la radiografía carpal.

Due the importance of diagnosis precocious of osteoporosis, this study carried out the comparison of two conventional radiological methods for the evaluation of bone density in postmenopausal women. X-ray images of panoramic and carpal were selected, corresponding to 68 women between 49 and 80 years old, obtained at the Clinic of Dental Radiology, for holding dental implant. The interpretation of bone density in jaw on panoramic radiography was the method to determine mandibular cortical thickness. The carpal radiography was evaluated for the radiogrammetry method. It was concluded that there was a correlation between low bone density observed in the mandibular panoramic radiography with low bone density on carpal radiography.

Undifferentiated osteosarcoma of the mandible oblique line: a case report / Osteossarcoma indiferenciado da mandíbula: relato de caso clínico na região do trígono retromolar

O osteossarcoma (OS) é o tumor maligno primário mais comum. Entretanto, o osteossarcoma localizado na mandíbula (JOS) é raro, agressivo e maligno, constituindo de 5-13% dos casos de OS do corpo todo. O JOS tem predileção pelo sexo masculino com idade de 34-36 anos. O prognóstico da doença está associado com diversas variáveis tais como a localização do tumor, fase de desenvolvimento, existência ou não de metástases, sexo, idade, e resposta do organismo ao tratamento. Este artigo relata um caso incomum de osteossarcoma localizado na região do trígono retromolar mandibular, composto por osso mesenquimal primitivo, que comumente ocorre nas regiões de extremidades e ossos longos...

This article reports a case of 82 years old woman, who consulted in a private radiology dental clinic for implants planning. In a panoramic radiography, a radiopaque area with sun-ray appearance located above the external oblique line on the right side was observed. The incisional biopsy showed presence of sarcomatous stroma presenting osteoid tissue with irregularly shaped and large amount of osteoblasts, varied sizes and shapes, with prominent nuclei, intensely colored, arranged in a disorderly way around trabecular bone. Histopathological diagnosis was obtained for undifferentiated osteosarcoma. Osteosarcoma located in the jaw (JOS) is rare and aggressive, constituting 5% to 13% of all cases of skeletal osteosarcoma. JOS has a male predilection in third decade of life...

Influence of the milliamperage settings on cone beam computed tomography imaging for implant planning.

PURPOSE: To evaluate the influence of the milliamperage settings on cone beam computed tomography (CBCT) images for qualitative and quantitative preoperative implant planning. MATERIALS AND METHODS: Eight dry mandibles were scanned under different milliamperage values (2, 4, 6.3, 8, 10, 12, and 15 mA) available for selection on the Kodak 9000 CBCT unit. Cross-sectional slices of incisor, canine, premolar, first molar, and second molar regions were analyzed by three oral radiologists. A subjective image quality evaluation of the height measurements compared with the real measurements obtained in the mandible were performed. After 30 days, 25% of the sample was reevaluated to obtain the reproducibility of the results. RESULTS: The weighted-kappa coefficient and intraclass correlation coefficient for intra- and interobserver agreement varied between moderate and substantial agreement for the image quality evaluation, and excellent agreement was found for the bone measurements. For the image quality evaluation, the Friedman test showed a negative influence of the milliamperage setting only when the lowest values (2 and 4 mA) were used; for the measurements, one-way analysis of variance with the post hoc Tukey test showed that milliamperage settings did not influence their accuracy. However, images obtained with 6.3 mA were closest to the real measurements. CONCLUSION: On the basis of this study of dried skulls using CBCT, it was determined that image quality degradation was not significantly improved when the milliamperage setting was increased above 6.3 mA, whereas a milliamperage level below 6.3 mA resulted in degradation of the image quality. Therefore, significant dose reduction can be achieved with diagnostically satisfactory image quality on CBCT exams for implant planning by reducing the milliamperage setting.