Association of volume and voxel intensity of the articular disc and lateral pterygoid muscle in migraine patients: a study with magnetic resonance imaging.

Objectives: To compare the volume and voxel intensity of articular disc and lateral pterygoid muscle (LPM) between a group of migraine patients and a control group (those without history of headache) by using magnetic resonance imaging (MRI).Patients and methods: MRI scans of 17 migraine patients and 15 healthy controls subjects were analysed and processed, using ITK-SNAP software, by a single investigator, for calculation of volumes and voxel intensity of articular disc and superior and inferior head of LPM.Results: There were statistically significant differences between migraine patients and controls regarding the volume and voxel intensity of articular disc and inferior head of LPM, increasing in migraine patients. Intra-rater was highly consistent and reproducible (intra-class correlation coefficient [ICC] = 1).Conclusions: Higher voxel intensity in disc and inferior head of LPM of MRI scans was linked to the increased volume of articular disc, inferior head of LPM and migraine.

Three-Dimensional Volumetric Investigation of Onodi Cells: A Multi-Slice Computed Tomography Study.

Introduction Onodi cells (OCs) are posterior ethmoid cells that are located above the sphenoid sinus, close to or even surrounding the carotid artery and optic nerve. Objective To investigate and evaluate the volumetric variation of OCs through multi-slice computed tomography (MSCT) scans. Methods We performed a retrospective review of MSCT scans of 79 subjects, 40 male and 39 female patients, Whose age ranged from 18 to 83 (mean: 39.6) years. The volumes of the OCs on the right and left sides were measured using the ITK-SNAP software (open-source) with semiautomatic segmentation. The possible relationships involving age, gender, contact with the optic nerve, extension of the pneumatization of the posterior ethmoid cells into the clinoid processes, mucous thickening in the anterior and posterior ethmoid cells, and obliteration of the sphenoethmoidal complex were analyzed with the Pearson correlation and Chi-squared tests according to the type of data compared and logistic regression models ( p < 0.05). Results We observed that an increase of one unit in the volume of OCs also increases the chance of extension of pneumatization into the clinoid processes by 0.15% ( p = 0.001). No significant correlations were identified regarding age, gender, and volume of the OCs. Conclusion The volume of the OCs has effects on the extension of pneumatization into the clinoid processes.

Three-Dimensional Volumetric Analysis of Frontal Ethmoidal Cells and Evaluation of Influential Factors: A Helical Computed Tomography Study.

In the present study, we aimed to assess frontal ethmoidal cells by using segmentation 3D software to establish a possible correlation between volume variation and both gender and age, as well as a relationship with Keros classification. Helical computed tomography images were obtained from 71 patients for analysis, in which the agger nasi cell, supra agger cell, supra agger frontal cell, supra bulla frontal cell, supraorbital ethmoidal cell, supra bulla cell, and frontal septal cell were identified and segmented to obtain their volume. Significant differences in volume were found for age and gender regarding agger nasi cells (p-value = 0.017), supra agger cells (p-value < 0.001), and frontal septal cells (p-value = 0.049). In the frontal septal cells, an increase of one year in age reduced the volume by 0.309, on average. According to Keros classification, the mean volumes were 10.07 and 25.64, respectively, for types II and III, both being greater than that of type I. Extracting volumetric data by using segmentation software in agger nasi cells, supra agger cells, and frontal septal cells may be useful for obtaining additional information related to age, in addition to possibly contributing to elucidating the anatomical variations in the region and an identification forensic tool.

Cone Beam Computed Tomography-Based Anatomical Assessment of the Olfactory Fossa.

This study aimed to investigate the olfactory fossa according to the Keros classification using cone beam computed tomography. This cross-sectional study analysed cone beam computed tomography images selected from a database belonging to a radiology centre. The scans of 174 healthy patients were analysed by using the Xoran software. Gender, age, and side were correlated with the Keros classification. The mean age of the 174 patients was 45.3 years. The most prevalent Keros classification was type II (65.52%), followed by type III (20.69%) and type I (13.79%). No significant differences were found between Keros classification and the variables age, right side (p value = 0.4620), and left side (p value = 0.5709). There were also no significant differences between gender and the variables right side (p value = 0.1421) and left side (p value = 0.2136). Based on these results, we suggest that cone beam computed tomography can be recommended for analysis of the anterior skull base. Keros type II was the most prevalent type in our sample.

Bilateral mandibular buccal bifurcation cyst: a case report emphasizing the role of imaging examination in the diagnosis.

A mandibular buccal bifurcation cyst is an inflammatory cyst that usually occurs on the buccal aspect of the permanent mandibular first molar of children. This lesion is diagnosed by an association of radiographic, clinical, and histological features. We report a bilateral case of mandibular buccal bifurcation cyst and discuss the main findings of this entity. A 7-year-old girl presented pain and delayed dental eruption in the posterior mandibular region. A cone beam computed tomography was performed and revealed hypodense lesions involving the crown and root of the mandibular first molars, with expansion of the buccal cortical and lingual tilting of the molar roots. A biopsy was carried out, and the common features of an inflammatory odontogenic cyst were histologically observed. The final diagnosis was bilateral mandibular buccal bifurcation cyst. Clinicians need to be aware of this diagnostic possibility in cases of mandibular cysts in children-especially when bilateral-to perform the correct treatment, which should not involve the extraction of the affected tooth.

Three-Dimensional Volumetric Investigation of Onodi Cells: A Multi-Slice Computed Tomography Study

Abstract Introduction Onodi cells (OCs) are posterior ethmoid cells that are located above the sphenoid sinus, close to or even surrounding the carotid artery and optic nerve. Objective To investigate and evaluate the volumetric variation of OCs through multi-slice computed tomography (MSCT) scans. Methods We performed a retrospective review of MSCT scans of 79 subjects, 40 male and 39 female patients, Whose age ranged from 18 to 83 (mean: 39.6) years. The volumes of the OCs on the right and left sides were measured using the ITK-SNAP software (open-source) with semiautomatic segmentation. The possible relationships involving age, gender, contact with the optic nerve, extension of the pneumatization of the posterior ethmoid cells into the clinoid processes, mucous thickening in the anterior and posterior ethmoid cells, and obliteration of the sphenoethmoidal complex were analyzed with the Pearson correlation and Chi-squared tests according to the type of data compared and logistic regression models (p < 0.05). Results We observed that an increase of one unit in the volume of OCs also increases the chance of extension of pneumatization into the clinoid processes by 0.15% (p = 0.001). No significant correlations were identified regarding age, gender, and volume of the OCs. Conclusion The volume of the OCs has effects on the extension of pneumatization into the clinoid processes.

Influence of voxel size on the accuracy of linear measurements of the condyle in images of cone beam computed tomography: A pilot study.

BACKGROUND: To analyze the influence of voxel size and exposure time on the accuracy of linear measurements of the condyle. MATERIAL AND METHODS: Four macerated hemi-mandibles of pigs were scanned in nine different voxel size protocols. Three-dimensional models of the condyle were generated in order to establish a comparison between linear measurements obtained with each voxel protocol and those obtained with a caliper (gold standard). The comparison between the protocols was performed considering the average of the two measurements of the condyle in the latero-medial (LM) and antero-posterior (AP) axes and also through repeated measurement ANOVA with rank transformation. The level of significance was 5%. RESULTS: A significant difference was found between the protocols regarding the LM and AP variables (p-values = 0.0027 and 0.0263, respectively). In the LM axis, the protocol P6 (voxel size of 0.3 mm with scan time of 4.8 seconds) did not show statistical difference compared to the gold standard. The protocols P4 and P5 (voxel size of 0.25 mm with scan times of 14.7 and 26.9 seconds, respectively) were both statistically similar compared to caliper, although they have presented a longer scan time. In the AP axis, the protocol P8 (voxel size of 0.4 mm with time scan of 4.8 seconds) was statistically similar to the gold standard. CONCLUSIONS: A smaller voxel size does not necessarily mean more accuracy regarding the linear measurements of the condyle. It is possible to obtain an acceptable level of accuracy with a larger voxel size and a shorter exposure time to radiation. Key words:CBCT, voxel size, linear measurement, diagnostic imaging.

Magnetic resonance imaging texture analysis of the temporomandibular joint for changes in the articular disc in individuals with migraine headache / Análise de textura por ressonância magnética da articulação temporomanbibular com alterações no disco articular em individuos com cefaleia migranea

Objective: the aim of this study was to analyse the performance of the technique of texture analysis (TA) with magnetic resonance imaging (MRI) scans of temporomandibular joints (TMJs) as a tool for identification of possible changes in individuals with migraine headache (MH) by relating the findings to the presence of internal derangements. Material and Methods: thirty MRI scans of the TMJ were selected for study, of which 15 were from individuals without MH or any other type of headache (control group) and 15 from those diagnosed with migraine. T2-weighted MRI scans of the articular joints taken in closed-mouth position were used for TA. The co-occurrence matrix was used to calculate the texture parameters. Fisher's exact test was used to compare the groups for gender, disc function and disc position, whereas Mann-Whitney's test was used for other parameters. The relationship of TA with disc position and function was assessed by using logistic regression adjusted for side and group. Results: the results indicated that the MRI texture analysis of articular discs in individuals with migraine headache has the potential to determine the behaviour of disc derangements, in which high values of contrast, low values of entropy and their correlation can correspond to displacements and tendency for non-reduction of the disc in these individuals. Conclusion: the TA of articular discs in individuals with MH has the potential to determine the behaviour of disc derangements based on high values of contrast and low values of entropy (AU)

Objetivo: o objetivo deste estudo foi analisar o desempenho da técnica de análise de textura (AT) em exames de ressonância magnética (RM) das articulações temporomandibulares (ATM) como ferramenta para identificação de possíveis alterações em indivíduos com cefaléia migrânea (CM) relacionando os achados com a presença de desarranjos internos. Material e Métodos: trinta exames de RM das ATM foram selecionados para estudo, sendo 15 de indivíduos sem cefaleia migrânea ou qualquer outro tipo de cefaléia (grupo controle) e 15 diagnosticados com CM. As imagens de RM ponderadas em T2 das articulações realizadas na posição de boca fechada foram usadas para AT. A matriz de co-ocorrência foi usada para calcular os parâmetros de textura. O teste exato de Fisher foi usado para comparar os grupos quanto ao sexo, função do disco e posição do disco, enquanto o teste de Mann-Whitney foi usado para os demais parâmetros. A relação da AT com a posição e função do disco foi avaliada por meio de regressão logística ajustada para lado e grupo. Resultados: a AT por RM dos discos articulares em indivíduos com cefaleia migrânea tem o potencial de determinar o comportamento dos desarranjos discais, em que altos valores de contraste, baixos valores de entropia e sua correlação podem corresponder a deslocamentos e tendência a não redução do disco nesses indivíduos. Conclusão: a análise de textura dos discos articulares em indivíduos com CM tem potencial para determinar o comportamento dos desarranjos do disco com base em altos valores de contraste e baixos valores de entropia. (AU)

Dental care for patients with special needs at a private higher education institute / Atendimento odontológico a pacientes com necessidades especiais em uma instituição privada de ensino superior

Objetivo: Pacientes com necessidades especiais são aqueles indivíduos que necessitam de cuidados especiais por tempo indeterminado ou por toda a vida. O presente estudo tem como objetivo abordar o atendimento odontológico de pacientes com necessidades especiais em uma instituição privada de ensino superior da cidade de São Paulo. Material e Métodos: Foi realizado um estudo descritivo, retrospectivo, para análise de 210 prontuários odontológicos de pacientes com necessidades especiais atendidos no Departamento de Odontologia para Pacientes Especiais da Universidade Cruzeiro do Sul entre 2012 e 2018. Dados sobre sexo, idade, diagnóstico da condição debilitante, motivo da consulta, uso continuado de medicamentos, imagens radiográficas e tratamentos odontológicos prestados foram todos coletados e posteriormente submetidos à análise estatística descritiva e inferencial (teste do qui-quadrado) ao nível de significância de 5%. Resultados: Quanto aos tipos de procedimentos odontológicos avaliados no presente estudo, dos 210 pacientes, 24% necessitaram de tratamentos curativos dentários em que a terapia periodontal foi o tipo mais prevalente, enquanto os tratamentos endodônticos tiveram a menor prevalência, representando apenas 4%. Houve alta prevalência de doenças crônicas sistêmicas, acometendo 56% dos casos, cuja faixa etária era superior a 40 anos. Conclusão: Check-ups odontológicos regulares devem ser priorizados em pacientes com necessidades especiais para evitar intervenções mais invasivas como em nosso grupo (AU)

Objective: Patients with special needs are those individuals who need special care for an undetermined period of time or for lifetime. The present study is aimed to address the dental care of special needs patients at a private higher education institute in the city of São Paulo. Material and Methods: A descriptive, retrospective study was performed for analysis of 210 dental records of special needs patients who were treated at the Dental Department for Special Patients of the Cruzeiro do Sul University between 2012 and 2018. Data on gender, age, diagnosis of the debilitating condition, reason of the consultation, continued use of medications, radiographic images and dental treatments provided were all collected before being submitted to descriptive and inferential statistical analysis (chi-square test) at a significance level of 5%. Results: As for the types of dental procedures assessed in the present study, of the 210 patients, 24% needed dental curative treatments in which periodontal therapy was the most prevalent type, whereas endodontic treatments had the lowest prevalence, representing 4% only. There was a high prevalence of chronic systemic diseases, affecting 56% of the dental records, whose age group was above 40 years old. Conclusion: Regular dental check-ups should be prioritized in patients with special needs to avoid more invasive interventions as found in our group (AU)

3D Morphology Analysis of TMJ Articular Eminence in Magnetic Resonance Imaging.

PURPOSE: The objective of this study was to evaluate the computational reconstruction of the articular eminence of the temporomandibular joint (TMJ) based on magnetic resonance imaging (MRI) and semiautomatic volumetric segmentation techniques for morphological classification of the TMJ structure. MATERIALS AND METHODS: A total of 36 MRI scans of TMJ individuals were selected and formatted by using the ITK-SNAP software, consisting of MRI segmentation and generation of 3D models. The TMJ articular eminences were also classified according to the morphology analysis of the articular eminence in 3D reconstructions. Two independent trained and calibrated investigators performed the image analysis, which was repeated after thirty days. RESULTS: There was no association between sex and eminence shape (p = 0.456). Fisher's test revealed no statistically significant association between disc classification and eminence shape on both sides (p = 0.629). Chi-square test showed a significant statistically association between disc classification and disc displacement (p = 0.000). Intra- and interrater correlation coefficients showed excellent reproducibility values. CONCLUSIONS: Anatomical variability of the sample investigated was found, with predominantly round shape and presence of correlation between this shape and normal disc position. The correlation of flattened and convex shapes with disc position reduction indicated that type of disc derangement is more prevalent.

Prevalence of bifid mandibular canals by cone beam computed tomography.

PURPOSE: The aim of this study was to evaluate the prevalence of bifid mandibular canals (BMC) by cone beam computed tomography (CBCT). MATERIALS AND METHODS: We examined CT scans from 300 patients both male and female, aged 25 to 87 years. The subjects were divided into groups according to gender, male group (MG) and female group (FG) as well as subgroups according to the side, right (R) and left (L). Tomographic acquisitions were performed on the device I-Cat ® Classic. Image analysis was performed on the XoranCat ® software of the equipment itself, aided by image filters associated with transverse, oblique, and panoramic reconstruction cuts for analysis of the BMC. The results were displayed as descriptive analysis of the values and comparisons between factors were performed using ANOVA at a significance level of 95 %. RESULTS: BMC was observed in 80 cases (26.67 %), of which, 39 (48.75 %) were in males and 41 (51.25 %) in females; no difference was seen between genders, neither by affected side, although the right side was more frequently affected (66.67 %) when both genders were combined. CONCLUSION: The prevalence of BMC is significant and should not be overlooked.

Three-dimensional lateral pterygoid muscle volume: MRI analyses with insertion patterns correlation.

We evaluated lateral pterygoid muscle volume in closed and open mouth positions in association with anterior disc displacement, effusion and abnormal articular disc shape from three-dimensional reformations of MRI. A total of 24 MRI of a sample (15 females, 9 males) aged 19-64 years (37.2 years±11.4) were assessed. Segmentation and volumetric assessment of the total, upper and lower heads of the lateral pterygoid muscle were performed using free software. The upper head of the lateral pterygoid muscle had a smaller volume than the lower head at both sides, in the closed- and open-mouth positions. In the open-mouth position, individuals with a subdivided upper head, where one component was inserted in the articular disc and another in the mandibular head, displayed a significantly larger volume of the upper head compared to individuals who had a single attachment to the articular disc (p=0.0130). The lateral pterygoid muscle has different volumes in the closed- and open-mouth positions. Gender affected muscle volume, specifically the upper head component. Insertion type in the upper head also seemed to affect muscle volume.

Value of Magnetic Resonance Imaging for Diagnosis of Dentigerous Cyst.

Odontogenic cysts have a high prevalence in the dental clinic population, with dentigerous cyst being one of the most frequent ones and whose aetiology involves accumulation of fluid between the reduced enamel epithelium and the crown of an unerupted tooth. In the diagnostic process of these lesions, one should consider complementary imaging exams such as conventional radiography and computed tomography, which are commonly used for providing anatomical information on the tissues compromised by the lesion, but not on the nature of it. Magnetic resonance imaging (MRI) scans are noninvasive modalities which, due to their unique acquisition characteristics, can provide distinct information on the nature of the lesion. This study reports on a case of dentigerous cyst in the mandible of a 9-year-old patient, documented by means of different imaging modalities. MRI played an important role in both diagnosis of the lesion and differential diagnosis between neoplastic lesions presenting similar imagenological behaviour under other techniques of radiography.

Imaging Aspects of Palatal Torus in Cone Beam Computed Tomography and Magnetic Resonance: Case Report.

The torus palatinus is a unilocular or multilocular exostosis that occurs in the midline of the hard palate. It is considered a common clinical finding. Magnetic resonance imaging (MRI) is not commonly used in dentistry and descriptions of the torus by this imaging method are therefore rare in the literature. This case study reports on a female patient referred to the dentist to elucidate a bone enlargement detected by MRI, which was requested by the physician who accompanied the patient for migraine treatment. Additional routine dental imaging exams were performed for the planning of different treatments. Here is a description of the torus palatinus along with MRI in order to provide a complete representation of the clinical finding.

Location and classification of Canalis sinuosus for cone beam computed tomography: avoiding misdiagnosis.

The aim of this study was to assess the presence, location and, multiplanar distance of the canalis sinuosus (CS) between the incisive foramen and the anterior maxillary alveolar ridge using cone beam computed tomography (CBCT). Therefore, 500 CBCT maxillary images obtained from male and female patients aged 20 to 80 years were selected to assist in the dental treatment. Low-quality tomographic images were discarded. All images were captured with the i-CATTM Classic tomograph and assessed using the XoranCatTM software. The axial sections were analyzed at the incisive foramen in order to verify the CS presence in laterality and location. Furthermore, linear measurements of the nasal cavity floor, buccal cortical bone, and alveolar ridge crest were made. All the collected data were statistically analyzed. Results show a variation of the CS in relation to the classification and distance of anatomical structures, but no significant difference between the right and left sides. It should be highlighted that CBCT is necessary before invasive procedures in order to preserve important anatomical structures. In conclusion, the location of the CS varies in relation to the alveolar ridge crest and buccal cortical bone, assuming that it is going to be located by the upper lateral incisor palatine.

Cone Beam Computed Tomography Based Sex Estimation by Volume of Odontoid Process of The Second Cervical Vertebra / Estimativa sexual baseada em tomografia computadorizada de feixe cônico pelo volume do processo odontóide da segunda vértebra cervical

Objective: The aim of this study was to evaluate whether the volume of odontoid process of the second cervical vertebra on CBCT images can be used for sex estimation. Material and Methods: The volume of odontoid process on CBCT images of 138 subjects was measured. In addition, the patients were classified into five age groups. The comparisons between the groups in relation to sex and age were performed by using Mann-Whitney's test and Kruskal-Wallis' test, respectively. The ROC curve was used to assess the sensitivity and specificity of the volume to determine the sex. Results: No statistically significant difference was observed between age and volume. Males had significantly larger volumes than females. Values of volume equal to or greater than 1.254 mm3 have sensitivity of 68.2% and specificity of 68.1% to determine male sex. Conclusion: The volume of the odontoid process tends to be larger in males than in females and can be used as sex estimation (AU)

Introdução: O objetivo deste estudo foi avaliar se o volume do processo odontóide da segunda vértebra cervical em imagens de TCFC pode ser usado para estimativa do sexo. Material e Métodos: O volume do processo odontóide em imagens CBCT de 138 indivíduos foi medido. Além disso, os pacientes foram classificados em cinco faixas etárias. As comparações entre os grupos em relação ao sexo e idade foram realizadas por meio dos testes de Mann-Whitney e Kruskal-Wallis, respectivamente. A curva ROC foi utilizada para avaliar a sensibilidade e especificidade do volume para determinar o sexo. Resultados: Não foi observada diferença estatisticamente significativa entre idade e volume. Os machos tiveram volumes significativamente maiores do que as fêmeas. Valores de volume igual ou superior a 1,254 mm3 apresentam sensibilidade de 68,2% e especificidade de 68,1% para determinação do sexo masculino. Conclusão: O volume do processo odontóide tende a ser maior no sexo masculino do que no feminino e pode ser usado como estimativa do sexo. (AU)

Squamous Odontogenic Tumor: Literature Review Focusing on the Radiographic Features and Differential Diagnosis.

Since its first publication in 1975, the squamous odontogenic tumor remains the rarest odontogenic lesion, with around 50 cases in the English-language literature in which the microscopic characteristics are frequently very well demonstrated. However, articles which discuss the radiographic aspects are scarce, especially with emphasis on the differential diagnosis. The present treatise proposes an assessment of jaw lesions with the same radiographic characteristics of the squamous odontogenic tumor to clarify the main findings for dental clinicians during routine diagnosis.

Lateral pterygoid muscle volume and migraine in patients with temporomandibular disorders.

PURPOSE: Lateral pterygoid muscle (LPM) plays an important role in jaw movement and has been implicated in Temporomandibular disorders (TMDs). Migraine has been described as a common symptom in patients with TMDs and may be related to muscle hyperactivity. This study aimed to compare LPM volume in individuals with and without migraine, using segmentation of the LPM in magnetic resonance (MR) imaging of the TMJ. MATERIALS AND METHODS: Twenty patients with migraine and 20 volunteers without migraine underwent a clinical examination of the TMJ, according to the Research Diagnostic Criteria for TMDs. MR imaging was performed and the LPM was segmented using the ITK-SNAP 1.4.1 software, which calculates the volume of each segmented structure in voxels per cubic millimeter. The chi-squared test and the Fisher's exact test were used to relate the TMD variables obtained from the MR images and clinical examinations to the presence of migraine. Logistic binary regression was used to determine the importance of each factor for predicting the presence of a migraine headache. RESULTS: Patients with TMDs and migraine tended to have hypertrophy of the LPM (58.7%). In addition, abnormal mandibular movements (61.2%) and disc displacement (70.0%) were found to be the most common signs in patients with TMDs and migraine. CONCLUSION: In patients with TMDs and simultaneous migraine, the LPM tends to be hypertrophic. LPM segmentation on MR imaging may be an alternative method to study this muscle in such patients because the hypertrophic LPM is not always palpable.

Study of the pterygoid canal (vidian canal) through images of cone beam computer tomography / Estudo do canal Pterigóideo (canal Vidiano) por meio de imagens de tomografia computadorizada de feixe cônico

Objective: The aim of this study was to evaluate the pterygoid canal (PC) by Cone Beam Computed Tomography (CBCT), establishing its configuration and proximity with anatomical structures. Material and Methods: We evaluated 398 CBCT exams, all from a public University radiology clinic archive. Four parameters were evaluated: single or double PC, distance between PC and the inferior part of the sphenoid sinus (SS), ratio of PC and SS and the distance between the PC and the foramen rotundum. Results: It was observed that most of the PC of the sample presented simple morphology, the most frequent type of relationship between the PC and the SS on both sides was the close contact with the wall. Among the cases that there were some distances between the PC and the inferior wall of the SS, the mean of this distance did not exceed 3.20 mm, being the left side (3.03 mm) slightly closer than the right (3.20 mm). Finally, the distances between the PC and the corresponding Foramen Rotundum are presented with mean values of 5.87 mm for the right side and 6.31 mm for the left side. Conclusion: CBCT examination is of paramount importance for PC identification; once in the studied sample, the mean values found evidence the close relation between the PC and the SS (AU)

Objetivo: O objetivo deste estudo foi avaliar o CP pela TCFC, estabelecendo sua configuração e proximidade com estruturas anatômicas. Material e Métodos: Foram avaliados 398 exames de TCFC, todos de um arquivo público da clínica de radiologia da Universidade. Foram avaliados quatro parâmetros: CP único ou duplo, distância entre PC e parte inferior do seio esfenoidal (SS), razão entre PC e SS e a distância entre o PC e o forame redondo. Resultados: Observou-se que a maioria dos CP da amostra apresentava morfologia simples, o tipo de relação mais frequente entre o CP e o SS de ambos os lados foi o contato próximo com a parede. Entre os casos em que houve algumas distâncias entre o CP e a parede inferior da ES, a média dessa distância não excedeu 3,20 mm, sendo o lado esquerdo (3,03 mm) um pouco mais próximo do que o direito (3,20 mm). Finalmente, as distâncias entre o PC e o forame redondo correspondente são apresentadas com valores médios de 5,87 mm para o lado direito e 6,31 mm para o lado esquerdo. Conclusão: O exame TCFC é de suma importância para a identificação do CP; uma vez na amostra estudada, os valores médios encontrados evidenciam a estreita relação entre o CP e o SS. (AU)

Diagnostic value of magnetic resonance imaging in the analysis of ameloblastoma: report of two cases / Valor diagnóstico da ressonância magnética na análise do ameloblastoma: relato de dois casos

Ameloblastoma is an odontogenic tumor that shares clinical and imaging characteristics with other lesions of the jaws, such as odontogenic keratocyst, which makes the diagnosis difficult.However, in addition to radiographic and tomographic examinations, Magnetic Resonance Imaging (MRI) has been increasingly used, contributing with relevant additional information about thedifferentiation between solid and liquid components of the lesion. This case report was conducted to present two variations of ameloblastoma and discuss the radiographic, tomographic and MRI contribution in the differential diagnosis between ameloblastoma and odontogenic keratocyst. The signal intensity in T1-weighted MRI revealed internal fluid content in both cases, which was important in the differential diagnosis with other intraosseous lesions such as odontogenic keratocysts. This is probably due to the presence of keratin that increases the viscosity of the content and also for an intermediate signal intensity signal in T2-weighted MRI. Therefore, MRI revealed important internal characteristics of the reported lesions, which was very useful in the establishment of the differential diagnosis with other lesions. (AU)

O ameloblastoma é um tumor odontogênico que compartilha características clínicas e de imagem com outras lesões da mandíbula, como o ceratocisto odontogênico, o que dificulta o seu diagnóstico. Entretanto, além dos exames radiográficos e tomográficos, a ressonância magnética (RM) tem sido cada vez mais utilizada, contribuindo com informações adicionais relevantes sobre a diferenciação entre componentes sólidos e líquidos da lesão. Este relato de caso apresenta duas variações de ameloblastoma e discuti a contribuição radiográfica, tomográfica e da RM no diagnóstico diferencial entre o ameloblastoma e o ceratocisto odontogênico. A RM ponderada em T1 revelou conteúdo líquido interno em ambos os casos relatados, o que foi importante no diagnóstico diferencial com outras lesões intraósseas, como os ceratocistos odontogênicos. Isto ocorre devido à presença de queratina aumentar a viscosidade do conteúdo e também gerar um sinal de intensidade intermediária na RM ponderada em T2. Portanto, a RM revelou importantes características internas das lesões relatadas, o que foi muito útil no estabelecimento do diagnóstico diferencial com outras lesões. (AU)