Search

Supernumerary teeth are dental units that appear in addition to the regular number of teeth.Their most common location is at the level of the anterior midline of the maxilla, known asmesiodens, but they can also be paramedian; or in the position of a lateral incisor. This article reviews the case of an inverted permanent supernumerary mesiodens in a child aged 15 years and 3 months. The patient was non-syndromic and did not have any other supernumerary teeth in the permanent dentition. Using cone beam computed tomography (CBCT) of the region, we were able to assess the position, structure, and shape of the supernumerary, as well as establish an adequate treatment plan. The aim of this paper was to present this anomalous case of an inverted supernumerary tooth located in the palate, and to include a review of the literature on the few reported cases of this type., Los dientes supernumerarios son unidades dentales que aparecen además del número regular de dientes. Su ubicación más frecuente es a nivel de la línea media anterior del maxilar, que se llama mesiodens, pero también paramediano; o en la posición de un incisivo lateral. Este artículo revisa el mesiodens invertido permanente supernumerario en un niño de 15 años 3 meses. El paciente no era sindrómico y no presentaba ningún otro diente supernumerario en la dentición permanente. Utilizando la tomografía computarizada de haz cónico (CBCT) de la región, pudimos evaluar la posición, la estructura y la forma del supernumerario, así como establecer un adecuado plan de tratamiento. El objetivo de este documento fue presentar este caso anómalo de un diente supernumerario invertido ubicado en el paladar, e incluir una revisión de la literatura de los pocos casos reportados de este tipo.

Aim: This study aimed to collect evidence on the validity and reliability of measurements obtained from digital impression techniques. Materials and Methods: This comparative study was conducted on 31 patients. Intraoral scanner was applied to all patients. For each patient, an alginate impression of the upper maxilla was taken and later the 3D digital model was extracted by dental cone-beam computed tomography (CBCT). For preparation of plaster models, alginate impressions were taken and immediately poured with dental stone. In the next stage, a comparison was performed among the intraoral scanner, CBCT, and plaster models in terms of tooth size, dental width, and intra-arch dimensions. Results: Measuring tooth size and intra-arch dimensions in digital images obtained from intraoral scanner and CBCT were in most cases lower than the results obtained in the plaster models but the differences between digital techniques and plaster models are not clinically noticeable. Conclusions: Digital systems including intraoral scanner and CBCT are acceptable for clinical use in terms of accuracy., Objetivo: Este estudio tuvo como objetivo recopilar evidencia sobre la validez y confiabilidad de las mediciones obtenidas a partir de técnicas de impresión digital. Materiales y Métodos: Este estudio comparativo se realizó en 31 pacientes. A todos los pacientes se les aplicó escáner intraoral. Para cada paciente, se tomó una impresión de alginato del maxilar superior y posteriormente se extrajo el modelo digital 3D mediante Tomografía computarizada de haz cónico (CBCT) dental. Para la preparación de los modelos de yeso se tomaron impresiones de alginato y se vertieron inmediatamente con yeso dental. En la siguiente etapa, se realizó una comparación entre el escáner intraoral, CBCT y los modelos de yeso en términos de tamaño de diente, ancho dental y dimensiones intraarcada. Discusión: Se encontró que la apariencia microscópica de las células fusiformes era comparable en ambos grupos. Los resultados de la citometría de flujo demostraron expresiones comparables en ambos grupos, siendo las muestras positivas para CD90, CD73, CD105, HLA ABC y negativas para CD34, CD45 y HLA DR. Hubo variaciones en la expresión de los marcadores cuando se evaluaron los potenciales de diferenciación. Conclusión: Los sistemas digitales como el escáner intraoral y el CBCT son aceptables para uso clínico en términos de precisión.

To develop a modular anthropomorphic phantom to evaluate the performance of radiological techniques for detecting pathologies in the temporal bone region. A phantom was constructed using a human skull, temporal bone specimen, and 3D-printed contour of a human skull. The human skull was embedded in tissue-equivalent plastic, with a cavity to hold the plastic jars containing the exchangeable freshly frozen human temporal bones. Subsequently, stepwise introduction and examination of different clinicopathological scenarios were conducted. Radiological images were nearly identical to those acquired from patients using computed tomography (CT) and cone beam computed tomography (CBCT). The radiological attenuation of polyurethane plastic (PUR) and alginate were similar to those of the soft tissues of living human patients. The mean Hounsfield unit values of the CT slices representing tissue at the brain and temporal bone level were 184 and 171 in the phantom and patient groups, respectively. The modular phantom developed in this study can evaluate radiological techniques and diagnostic possibilities without exposing patients to radiation. To our knowledge, no such modular phantom has been reported in the literature or made available commercially.

Background: The placement of implants into the alveolar socket right after tooth extraction is called immediate implant placement (IIP). This approach has its particularities depending on which region of the jaws is involved. The anterior mandible region is peculiar due to the presence of mandibular incisors, which have the shortest roots among all permanent teeth. Purpose: This study aimed to investigate the factors that could be associated with the risk of either cortical bone wall perforation or invasion of the 2 mm secure distance from the surrounding anatomical structures (defined as unsafe implant placement), with IIP in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. Materials and methods: CBCT exams from 239 eligible subjects were investigated. Implants were virtually placed in two distinct positions: prosthetically-driven (along the long axis of the existing tooth) and bone-driven position (according to the available bone and with regard to nearby anatomical structures). Correlation between several variables was tested, and binary logistic regression analysis in order to assess of the possible associations between covariates and unsafe placement was performed. Results: Safe placing implants was significantly higher for the bone-driven in comparison to the prosthetically-driven position (22.2% vs. 3.3%, respectively), and the 2-mm secure distance from anatomical structures was not possible to respect in the majority of cases (77.6% vs. 82.9%, respectively). Covariates associated with a higher risk of unsafe placement were tooth region (CI in relation to IL and CA), decrease of labial concavity angle (LCA), decrease of mandible basal bone height (MBBH), and decrease in mandibular bone thickness at the tooth apex level (MBT0). Conclusion: The possibility of safely placing immediate implants in the anterior mandible is significantly higher for bone-driven than in prosthetically driven position. Presurgical virtual planning

To develop a modular anthropomorphic phantom to evaluate the performance of radiological techniques for detecting pathologies in the temporal bone region. A phantom was constructed using a human skull, temporal bone specimen, and 3D-printed contour of a human skull. The human skull was embedded in tissue-equivalent plastic, with a cavity to hold the plastic jars containing the exchangeable freshly frozen human temporal bones. Subsequently, stepwise introduction and examination of different clinicopathological scenarios were conducted. Radiological images were nearly identical to those acquired from patients using computed tomography (CT) and cone beam computed tomography (CBCT). The radiological attenuation of polyurethane plastic (PUR) and alginate were similar to those of the soft tissues of living human patients. The mean Hounsfield unit values of the CT slices representing tissue at the brain and temporal bone level were 184 and 171 in the phantom and patient groups, respectively. The modular phantom developed in this study can evaluate radiological techniques and diagnostic possibilities without exposing patients to radiation. To our knowledge, no such modular phantom has been reported in the literature or made available commercially.

Background: The placement of implants into the alveolar socket right after tooth extraction is called immediate implant placement (IIP). This approach has its particularities depending on which region of the jaws is involved. The anterior mandible region is peculiar due to the presence of mandibular incisors, which have the shortest roots among all permanent teeth. Purpose: This study aimed to investigate the factors that could be associated with the risk of either cortical bone wall perforation or invasion of the 2 mm secure distance from the surrounding anatomical structures (defined as unsafe implant placement), with IIP in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. Materials and methods: CBCT exams from 239 eligible subjects were investigated. Implants were virtually placed in two distinct positions: prosthetically-driven (along the long axis of the existing tooth) and bone-driven position (according to the available bone and with regard to nearby anatomical structures). Correlation between several variables was tested, and binary logistic regression analysis in order to assess of the possible associations between covariates and unsafe placement was performed. Results: Safe placing implants was significantly higher for the bone-driven in comparison to the prosthetically-driven position (22.2% vs. 3.3%, respectively), and the 2-mm secure distance from anatomical structures was not possible to respect in the majority of cases (77.6% vs. 82.9%, respectively). Covariates associated with a higher risk of unsafe placement were tooth region (CI in relation to IL and CA), decrease of labial concavity angle (LCA), decrease of mandible basal bone height (MBBH), and decrease in mandibular bone thickness at the tooth apex level (MBT0). Conclusion: The possibility of safely placing immediate implants in the anterior mandible is significantly higher for bone-driven than in prosthetically driven position. Presurgical virtual planning

Aim: Several factors influence the condition of the periapical tissues associated with root filled teeth. The primary objective of this study was to retrospectively evalu ate the extent and speed of bone healing of large periapical lesions associated with nonsurgical root canal treatment or retreatment. The secondary objective was to analyse the relationship between the time to complete healing when analysed using cone beam computed tomography (CBCT) and other possible predictors that affect healing. Methodology: Seventy-nine patients were treated during the years 2013–2020 with large periapical lesions of endodontic origin (10–15mm) as observed on intraoral periapical radiographs (IOPAR) were included. IOPAR and CBCT were available before treatment and during the follow-up (IOPAR every 6months and CBCT every 12months). The volume of periapical lesions was calculated by OsiriX Lite software. Variables such as initial volume of the lesion, age, gender, type of treatment or type of root canal filling were compared to identify the differences between healed and unhealed lesions. Pearson's Chi-square test was used for categorical variables, the t-test for age and the Wilcoxon test for initial volume of the lesion. The association between time to healing and the variables was assessed using univariate analysis and multivariate analysis. The Wilcoxon test was used to observe the association of heal ing time with categorical variables and the correlation index was measured with the quantitative variables. Results: Of the 79 cases analysed, 60 lesions (76%) were completely healed as verified by CBCT in a mean healing time of 19months, of which 60% healed fully between 12 and 18months. Increase in age of patient and larger initial volume of the lesion were associated with a significantly longer healing time (p<.001). Gender, filling material and type of treatment did not have a significant effect on the healing process (p>.05).

n the context of diagnosing and planning treatment for patients with dentofacial deformities, it is crucial to examine the upper airway, as its function may be compromised by the facial skeletal pattern or impacted by planned surgical intervention. Cone Beam Computed Tomography (CBCT) is positioned as the preferred option for evaluation due to its precision and ability to predict possible changes. Objective: to evaluate the volume of the upper airway in different facial skeletal patterns of a population ofstudents from the University of Cuenca at TCHC. Materials and methods: 33 tomographies were evaluated through the Sidexis 4 program, where the volume of the nasopharynx, oropharynx, and hypopharynx was measured according to facial skeletal pattern and sex. Results: Of the 33 CBCT analyzed, 10 (30%) belonged to males and 23 (70%) to females. Within the population of patients with skeletal class I, it was found that the volume of the oropharynx was greater compared to the nasopharynx and hypopharynx, thus obtaining an average of 21.87 cm3, with a standard deviation of 5.09. Conclusions: The average volume of the upper airway in subjectswith Class I facial skeletal patterns is higher than in Class II, thus being statistically significant in the oropharynx. It is recommended to conduct studies with a larger population involving Class III skeletal patterns.

The aim of this research was to obtain regression equations for estimating age and gender determination in three slices of maxillary central incisors and molars using CBCT. Material and Methods. A total of 360 randomly selected CBCTs were included in this cross-sectional study. The sample size was determined by means of the Slovin’sformula. Results. The equations obtained from sagittal linear measurements and ratios presented a standard error of the estimate (SEE) of 12.4 years. The binary logistic regression models for predicting gender indicated that ace_MDTL demonstrates a significant positive effect on predicting male gender. Conclusion. The present study shows that CBCT linear measurements on upper central incisors and upper first molar are an acceptable method for age and gender estimation.

Cone Beam Computed Tomography is a technology to visualize the 3D interior anatomy of a patient. It is important for image-guided radiation therapy in cancer treatment. During a scan, iterative methods are often used for the image reconstruction step. A key challenge is the ill-posedness of the resulting inversion problem, causing the images to become noisy. To combat this, regularizers can be introduced, which help stabilize the problem. This thesis focuses on Adversarial Convex Regularization that with deep learning regularize the scans according to a target image quality. It can be interpreted in a Bayesian setting by letting the regularizer be the prior, approximating the likelihood with the measurement error, and obtaining the patient image through the maximum-a-posteriori estimate. Adversarial Convex Regularization has previously shown promising results in regular Computed Tomography, and this study aims to investigate its potential in Cone Beam Computed Tomography. Three different learned regularization methods have been developed, all based on Convolutional Neural Network architectures. One model is based on three-dimensional convolutional layers, while the remaining two rely on 2D layers. These two are in a later stage crafted to be applicable to 3D reconstruction by either stacking a 2D model or by averaging 2D models trained in three orthogonal planes. All neural networks are trained on simulated male pelvis data provided by Elekta. The 3D convolutional neural network model has proven to be heavily memory-consuming, while not performing better than current reconstruction methods with respect to image quality. The two architectures based on merging multiple 2D neural network gradients for 3D reconstruction are novel contributions that avoid memory issues. These two models outperform current methods in terms of multiple image quality metrics, such as Peak Signal-to-Noise Ratio and Structural Similarity Index Measure, and they also generalize well for real, Volymtomografi kan användas inom cancerbehandling för att skapa bilder av patientens inre anatomi i 3D som sedan används vid stråldosplanering. Under den rekonstruerande fasen i en skanning används ofta iterativa metoder. En utmaning är att det resulterande inversionsproblemet är illa ställt, vilket leder till att bilderna blir brusiga. För att motverka detta kan regularisering introduceras som bidrar till att stabilisera problemet. Fokus för denna uppsats är Adversarial Convex Regularization som baserat på djupinlärning regulariserar bilderna enligt en målbildskvalitet. Detta kan även tolkas ur ett Bayesianskt perspektiv genom att betrakta regulariseraren som apriorifördelningen, approximera likelihoodfördelningen med mätfelet samt erhålla patientbilden genom maximum-a-posteriori-skattningen. Adversarial Convex Regularization har tidigare visat lovande resultat för data från Datortomografi och syftet med denna uppsats är att undersöka dess potential för Volymtomografi. Tre olika inlärda regulariseringsmetoder har utvecklats med hjälp av faltningsnätverk. En av modellerna bygger på faltning av tredimensionella lager, medan de återstående två är baserade på 2D-lager. Dessa två sammanförs i ett senare skede för att kunna appliceras vid 3D-rekonstruktion, antingen genom att stapla 2D modeller eller genom att beräkna ett viktat medelvärde av tre 2D-modeller som tränats i tre ortogonala plan. Samtliga modeller är tränade på simulerad manlig bäckendata från Elekta. 3D-faltningsnätverket har visat sig vara minneskrävande samtidigt som det inte presterar bättre än nuvarande rekonstruktionsmetoder med avseende på bildkvalitet. De andra två metoderna som bygger på att stapla flera gradienter av 2D-nätverk vid 3D-rekonstruktion är ett nytt vetenskapligt bidrag och undviker minnesproblemen. Dessa två modeller överträffar nuvarande metoder gällande flera bildkvalitetsmått och generaliserar även väl för data från verklig Volymtomografi. Dessutom lyckas modellen som bygger på ett

This paper aims to perform a bibliographical comparison of imaging methods for the precise localization of root canals, specifically focusing on conventional radiography and cone beam computed tomography (CBCT). The methodology involves a systematic search in the online databases of Scielo and PubMed, including English-language studies published between 2018 and 2023 that are relevant to the research topic. The search revealed limitations associated with conventional radiography due to the superimposition of anatomical structures, which hinders the precise identification of root canals. Conversely, CBCT demonstrates greater reliability and precision when it comes to localizing these canals. Furthermore, CBCT proves effective in detecting anomalies, additional canals, and atypical anatomies or calcifications.Nonetheless, conventional radiography remains widely utilized, as it is performed in nearly all dental centers and is cost-effective. Therefore, when deciding which test to perform, it is important to consider factors such as availability, cost implications for the patient, and, above all, the specific clinical needs. In conclusion, there is enhanced accuracy in root canal localization and numerous advantages associated with three-dimensional visualization when performing CBCT, especially in complex cases. However, it is essential to keep in mind the considerations mentioned when conducting these procedures in endodontic treatments., El presente artículo, tiene el objetivo de comparar bibliográficamente los métodos de imagen en la localización precisa de los conductos radiculares, considerando a la radiografía convencional y a la tomografía computarizada de haz cónicoLa metodología radica en una búsqueda de forma sistemática en las bases de datos en línea de Scielo y PubMed, con la inclusión de estudios en inglés que hayan sido publicados entre 2018 y 2023 y que tengan relevancia dentro del tema de investigación; de dicha búsqueda se encontró que existen limitaciones en las radiografías convencionales, puesto que por la superposición de las estructuras anatómicas no se identifican de forma precisa los conductos radiculares. Por su parte se evidencia más confiabilidad y mayor precisión al realizar una tomografía computarizada cuando se requiere localizar los mencionados conductos, además con este último examen es más fácil identificar anomalías y conductos adicionales y, resulta efectiva al detectar anatomías atípicas o calcificaciones. No obstante, aún es muy utilizada la radiografía convencional, puesto que casi todos los centros odontológicos la realizan y su costo es bajo, por lo tanto, al momento de decidir qué prueba debe realizarse es importante considerar la disponibilidad, el valor económico que debe asumir el paciente y, sobre todo, qué tan especificas son las necesidades clínicas. En conclusión, hay mayor precisión de la localización de los conductos radiculares y más ventajas con la visualización tridimensional al realizar una tomografía computarizada, particularmente cuando se presentan casos complejos; sin embargo no hay que olvidar las consideraciones mencionadas cuando se requiere hacer este tipo de procedimientos en tratamientos endodónticos.

Dental age estimation is very important for individual identification in criminal and civil forensic investigations. One of the methods for age estimation is studying age related changes in pulp volume of teeth. The objective of the current study was to estimate dental age from the pulp volume of five different categories of teeth of a Peruvian sample using cone beam computed tomography (CBCT). Retrospective CBCT records of 231 patients [females (134), males (97), age: 12-60 years] were included in the study, categorized into five different age groups (12-19, 20-29, 30-39, 40-49, 50-59, 60 years and older). Dental pulp volume of five categories of teeth(upper canines, left upper central incisors, left upper first molars, lower left first premolars, first molars) were analyzed using Romexis® 5.3.3.5 software for each patient. There was a reduction in the pulp volume of upper right and left canine with age. The pulp volume was lowest in people aged 60 years and over. Linear regression analysis of the pulp volume and chronological age showed a coefficient of determination of 30%, suggesting a weak correlation. A weak correlation between dental pulp and age is derived. But, a robust large homogenous sample of teeth in future for different age groups may establish a reliable regression equation., La estimación de la edad dental en personas vivas y cadáveres es muy importante para la Odontología Forense, sobre todo en casos de identificación en investigaciones legales y sociales. El objetivo del estudio fue estimación de la edad dental mediante la medición del volumen pulpar de imágenes dentales en tomografía computarizada de haz cónico (TCHC) de pacientes peruanos. Fueron analizadas 231 TCHC de pacientes entre 12 a 60 años a más. [Mujeres (134), hombres (97)] se dividieron en seis grupos de edad (12-19, 20-29, 30-39, 40-49, 50-59, 60 años a más). El análisis volumétrico de la pulpa dental se realizó en un total de 1155 dientes (caninos superiores, incisivos centrales superiores izquierdos, primeros molares superiores izquierdos y primeros premolares inferiores izquierdos), mediante el software Romexis® 5.3.3.5. El análisis de regresión lineal mostró un coeficiente de determinación del 30% que sugiere una correlación débil entre la relación del volumen pulpar de los dientes y la edad. El volumen pulpar de los caninos superiores derecho e izquierdo disminuyó a medida que aumentaba la edad y el volumen pulpar en dientes de personas de 60 años a más fue el más bajo. Sin embargo, se pueden proponer estudios futuros para incluir una gran muestra homogénea de dientes en diferentes categorías y grupos de edad para confirmar la correlación y establecer una ecuación de regresión confiable.

To detect predictive factors for the occurrence of complications associated with unerupted maxillary canines (C). A total of 83 cone beam computed tomograms (CBCT), made from November 1, 2021 to October 31, 2022, have met the inclusion criteria, whereby 110 unerupted C were detected. Independent variables were: gender, age, and C position. Outcome variables were detected complications: external root resorption (ERR) and dilaceration of adjacent tooth, ERR and dilaceration of C, dentigerous cyst, canine ankylosis, and adjacent teeth malposition. Chi-square test and logistic regression analysis were used to examine the relationship between income variables and detected complications. Vertical position of unerupted C showed as predictor for adjacent tooth dilacerations and malposition. Chance for dilaceration increases 5.5-fold with C position at the middle third of lateral incisor (LI) root, while chance of malposition increases 23.4-fold with its supra-apical position to the LI root, in comparison to the C position occlusal to the LI cemento-enamel junction. Age is a predictive factor for dentigerous cysts, with decreasing the chance of their occurrence 1.5-fold with each additional year of age. Early evaluation of the vertical position and timely treatment of C are decisive steps in preventing complications.

Aim Several factors influence the condition of the periapical tissues associated with root filled teeth. The primary objective of this study was to retrospectively evaluate the extent and speed of bone healing of large periapical lesions associated with nonsurgical root canal treatment or retreatment. The secondary objective was to analyse the relationship between the time to complete healing when analysed using cone beam computed tomography (CBCT) and other possible predictors that affect healing. Methodology Seventy-nine patients were treated during the years 2013–2020 with large periapical lesions of endodontic origin (10–15 mm) as observed on intraoral periapical radiographs (IOPAR) were included. IOPAR and CBCT were available before treatment and during the follow-up (IOPAR every 6 months and CBCT every 12 months). The volume of periapical lesions was calculated by OsiriX Lite software. Variables such as initial volume of the lesion, age, gender, type of treatment or type of root canal filling were compared to identify the differences between healed and unhealed lesions. Pearson's Chi-square test was used for categorical variables, the t-test for age and the Wilcoxon test for initial volume of the lesion. The association between time to healing and the variables was assessed using univariate analysis and multivariate analysis. The Wilcoxon test was used to observe the association of healing time with categorical variables and the correlation index was measured with the quantitative variables. Results Of the 79 cases analysed, 60 lesions (76%) were completely healed as verified by CBCT in a mean healing time of 19 months, of which 60% healed fully between 12 and 18 months. Increase in age of patient and larger initial volume of the lesion were associated with a significantly longer healing time (p < .001). Gender, filling material and type of treatment did not have a significant effect on the healing process (p > .05). Conclusions Clinicians should be aware that

Cone Beam Computed Tomography is a technology to visualize the 3D interior anatomy of a patient. It is important for image-guided radiation therapy in cancer treatment. During a scan, iterative methods are often used for the image reconstruction step. A key challenge is the ill-posedness of the resulting inversion problem, causing the images to become noisy. To combat this, regularizers can be introduced, which help stabilize the problem. This thesis focuses on Adversarial Convex Regularization that with deep learning regularize the scans according to a target image quality. It can be interpreted in a Bayesian setting by letting the regularizer be the prior, approximating the likelihood with the measurement error, and obtaining the patient image through the maximum-a-posteriori estimate. Adversarial Convex Regularization has previously shown promising results in regular Computed Tomography, and this study aims to investigate its potential in Cone Beam Computed Tomography. Three different learned regularization methods have been developed, all based on Convolutional Neural Network architectures. One model is based on three-dimensional convolutional layers, while the remaining two rely on 2D layers. These two are in a later stage crafted to be applicable to 3D reconstruction by either stacking a 2D model or by averaging 2D models trained in three orthogonal planes. All neural networks are trained on simulated male pelvis data provided by Elekta. The 3D convolutional neural network model has proven to be heavily memory-consuming, while not performing better than current reconstruction methods with respect to image quality. The two architectures based on merging multiple 2D neural network gradients for 3D reconstruction are novel contributions that avoid memory issues. These two models outperform current methods in terms of multiple image quality metrics, such as Peak Signal-to-Noise Ratio and Structural Similarity Index Measure, and they also generalize well for real, Volymtomografi kan användas inom cancerbehandling för att skapa bilder av patientens inre anatomi i 3D som sedan används vid stråldosplanering. Under den rekonstruerande fasen i en skanning används ofta iterativa metoder. En utmaning är att det resulterande inversionsproblemet är illa ställt, vilket leder till att bilderna blir brusiga. För att motverka detta kan regularisering introduceras som bidrar till att stabilisera problemet. Fokus för denna uppsats är Adversarial Convex Regularization som baserat på djupinlärning regulariserar bilderna enligt en målbildskvalitet. Detta kan även tolkas ur ett Bayesianskt perspektiv genom att betrakta regulariseraren som apriorifördelningen, approximera likelihoodfördelningen med mätfelet samt erhålla patientbilden genom maximum-a-posteriori-skattningen. Adversarial Convex Regularization har tidigare visat lovande resultat för data från Datortomografi och syftet med denna uppsats är att undersöka dess potential för Volymtomografi. Tre olika inlärda regulariseringsmetoder har utvecklats med hjälp av faltningsnätverk. En av modellerna bygger på faltning av tredimensionella lager, medan de återstående två är baserade på 2D-lager. Dessa två sammanförs i ett senare skede för att kunna appliceras vid 3D-rekonstruktion, antingen genom att stapla 2D modeller eller genom att beräkna ett viktat medelvärde av tre 2D-modeller som tränats i tre ortogonala plan. Samtliga modeller är tränade på simulerad manlig bäckendata från Elekta. 3D-faltningsnätverket har visat sig vara minneskrävande samtidigt som det inte presterar bättre än nuvarande rekonstruktionsmetoder med avseende på bildkvalitet. De andra två metoderna som bygger på att stapla flera gradienter av 2D-nätverk vid 3D-rekonstruktion är ett nytt vetenskapligt bidrag och undviker minnesproblemen. Dessa två modeller överträffar nuvarande metoder gällande flera bildkvalitetsmått och generaliserar även väl för data från verklig Volymtomografi. Dessutom lyckas modellen som bygger på ett

Background With the increasing use of low dose CT scans, numerous pulmonary nodules are detected. As majority of them are benign, development of efficient non-surgical diagnostic intervention is mandatory. Electromagnetic navigation bronchoscopy (ENB) has been developed to reach difficult to access lesions. The aim of the present study was to compare the diagnostic yield of ENB procedures performed in a classical endoscopy suite or in a hybrid room equipped by a cone beam CT (CBCT). Methods A monocentric randomized study was performed in the Erasme Hospital between January 2020 and December 2021. Lung nodules of maximum 30 mm of diameter were eligible. In both arms (endoscopy or CBCT suites), ENB, fluoroscopic guidance and a radial endobronchial ultrasound were used to reach the lesion. Then six trans-bronchial biopsies (TBB) and one trans-bronchial lung cryobiopsy (TBLC) were performed. Primary outcomes were the diagnostic yield and diagnostic accuracy of the procedure. Results Forty-nine patients were randomized (24 in the endoscopy and 25 in the CBCT arms). The lesion size was 15,9 ± 4,6 mm and 16,6 ± 6,0 mm respectively (mean ± SD, p = NS). The diagnostic yield of ENB performed under CBCT guidance was 80% compared to 42% when performed in the endoscopy suite under standard fluoroscopic guidance ( p < 0,05). Similarly, the diagnostic accuracy in the CBCT group was 87% compared to 54% for the endoscopy group ( p < 0,05). Duration of the procedure in the CBCT and endoscopy arms was 80 ± 23 and 61 ± 13 min respectively (mean ± SD, p < 0,01). Performing TBLC in addition to TBB increased the diagnostic yield by 14% (17 and 12,5% in CBCT and endoscopy suites respectively, p = NS). Conclusion This study highlighted the additional value to perform ENB procedure under CBCT guidance for small size (less than 2 cm of diameter) pulmonary nodules. Trial registration Clinical trial registration number: NCT05257382., SCOPUS: ar.j, info:eu-repo/semantics/published

Background: Dens invaginatus is a developmental dental anomaly resulting from an invagination of dental tissues folding from the outer surface towards dental pulp. The aim of this systematic review and meta-analysis was to determine the prevalence of dens invaginatus using cone beam computed tomography (CBCT). Material and Methods: A systematic review was conducted following PRISMA statements. The research question was: What is the prevalence of dens invaginatus in the adult population assessed by CBCT? The MeSH terms were used to search articles published in the electronic database PubMed. Studies were selected considering predeter mined eligibility criteria. The Robins-I tool developed by Cochrane was used to assess methodological quality and risk of bias. Results: Four studies were included in this systematic review, including 2009 CBCT images. The overall preva lence of dens invaginatus was 9.0% (95% CI = 7.2 – 10.8%; p < 0.001). Three studies were considered of low risk of bias. Conclusions: The results of this systematic review and meta-analysis show that prevalence of dens invaginatus using CBCT was higher than previous estimations carried out with conventional radiographs. Therefore, an early identification and a correct management of invaginated teeth is essential for improving the prognosis of these teeth. It can be concluded that teeth with dens invaginatus should always be studied using CBCT

Background: Dens invaginatus is a developmental dental anomaly resulting from an invagination of dental tissues folding from the outer surface towards dental pulp. The aim of this systematic review and meta-analysis was to determine the prevalence of dens invaginatus using cone beam computed tomography (CBCT). Material and Methods: A systematic review was conducted following PRISMA statements. The research question was: What is the prevalence of dens invaginatus in the adult population assessed by CBCT? The MeSH terms were used to search articles published in the electronic database PubMed. Studies were selected considering predeter mined eligibility criteria. The Robins-I tool developed by Cochrane was used to assess methodological quality and risk of bias. Results: Four studies were included in this systematic review, including 2009 CBCT images. The overall preva lence of dens invaginatus was 9.0% (95% CI = 7.2 – 10.8%; p < 0.001). Three studies were considered of low risk of bias. Conclusions: The results of this systematic review and meta-analysis show that prevalence of dens invaginatus using CBCT was higher than previous estimations carried out with conventional radiographs. Therefore, an early identification and a correct management of invaginated teeth is essential for improving the prognosis of these teeth. It can be concluded that teeth with dens invaginatus should always be studied using CBCT

Background: Dens invaginatus is a developmental dental anomaly resulting from an invagination of dental tissues folding from the outer surface towards dental pulp. The aim of this systematic review and meta-analysis was to determine the prevalence of dens invaginatus using cone beam computed tomography (CBCT). Material and Methods: A systematic review was conducted following PRISMA statements. The research question was: What is the prevalence of dens invaginatus in the adult population assessed by CBCT? The MeSH terms were used to search articles published in the electronic database PubMed. Studies were selected considering predeter mined eligibility criteria. The Robins-I tool developed by Cochrane was used to assess methodological quality and risk of bias. Results: Four studies were included in this systematic review, including 2009 CBCT images. The overall preva lence of dens invaginatus was 9.0% (95% CI = 7.2 – 10.8%; p < 0.001). Three studies were considered of low risk of bias. Conclusions: The results of this systematic review and meta-analysis show that prevalence of dens invaginatus using CBCT was higher than previous estimations carried out with conventional radiographs. Therefore, an early identification and a correct management of invaginated teeth is essential for improving the prognosis of these teeth. It can be concluded that teeth with dens invaginatus should always be studied using CBCT

The aim of this study was to observed the anesthetic efficacy of the alveolar nerve block on nine patients that CBCT diagnosed unilateral retromolar canal on a double-blind, split-mouth approach. The assessments of patient response to thermal (pulp vitality test) and pressure (compression of soft tissue) stimuli were carried out before and 5 minutes after the inferior alveolar nerve block procedure, using both visual analog scale (VAS) and Mc Gill pain questionnaires (McG). The mean percentage of patient response decreased after alveolar nerve block, according to both VAS and McG, and was statistically similar among hemi mandibles with and without retromolar canal (Wilcoxon>0.05); however, those without retromolar canal presented greater reduction in patient response in 6 out of 9 cases. Therefore, the retromolar canal is not a determinant factor of inferior alveolar nerve block failure., El objetivo de este estudio fue observar la eficacia anestésica del bloqueo del nervio alveolar en nueve pacientes que CBCT diagnosticó canal retromolar unilateral en un abordaje de boca dividida doble ciego. Las evaluaciones de la respuesta del paciente a los estímulos térmicos (prueba de vitalidad pulpar) y de presión (compresión de los tejidos blandos) se realizaron antes y 5 minutos después del procedimiento de bloqueo del nervio alveolar inferior, utilizando tanto la escala analógica visual (VAS) como los cuestionarios de dolor de Mc Gill ( McG). El porcentaje medio de respuesta de los pacientes disminuyó tras el bloqueo del nervio alveolar, según EVA y McG, y fue estadísticamente similar entre hemimandíbulas con y sin canal retromolar (Wilcoxon>0,05); sin embargo, aquellos sin canal retromolar presentaron mayor reducción en la respuesta del paciente en 6 de 9 casos. Por lo tanto, el canal retromolar no es un factor determinante del fracaso del bloqueo del nervio alveolar inferior.

The aim of this study was to evaluate the prevalence and distribution of pulp stones in a group of Peruvian adults using cone beam tomography (CBCT). Materials and methods: 60 randomly selected CBCT from a tomographic center in Lima, Peru were analyzed. A total of 1263 images of teeth using the Point 3D Combi 500 S tomograph were evaluated. Images analysis was performed with Real Scan software and all teeth were evaluated in sagittal, axial and coronal views. All measurements were subjected to a chi square test. (p<0.05). Results: Of the 1263 teeth, 30.8% presented pulp calcifications through the CBCT. The prevalence of calcifications was higher in women than in men. The maxillary and mandibular molars were the groups of teeth with the highest frequency of pulp stones. There was significance between the pulp stones and the gender, age range, type and state of the tooth. Conclusions: The maxillary first molars had a higher prevalence of pulp calcifications than the mandibular ones. The presence of caries increased the possibility of the appearance of these calcifications, specifically in the maxillary teeth. CBCT could be a sensitive tool to detect pulp stones. Knowledge of the distribution of pulp stones can help dentists in the clinical treatment of endodontics., El objetivo de este estudio fue evaluar la prevalencia y distribución de cálculos pulpares en un grupo de adultos peruanos mediante tomografía de haz cónico (CBCT). Materiales y métodos: Se analizaron 67 tomografías de haz cónico seleccionadas aleatoriamente de un centro tomográfico en Lima, Perú. Fueron evaluadas 1263 imágenes de piezas dentarias mediante el tomógrafo Point 3D Combi 500 S. El análisis de las imágenes se realizó con el software Real Scan y todas las piezas dentarias fueron evaluadas en las vistas sagital, axial y coronal. Todas las medidas fueron sometidas a prueba de chi cuadrado. (p<0.05). Resultados: De un total de 67 pacientes, un 83,58% presentaron calcificaciones y de 1263 piezas dentarias, un 30.8% a través de la CBCT. La prevalencia de calcificaciones fue mayor en el sexo femenino que masculino. Los molares maxilares y mandibulares fueron los grupos de dientes con mayor frecuencia de cálculos pulpares. Se encontró significancia entre los cálculos pulpares y el género, rango de edad, tipo y estado de pieza dentaria. Conclusiones: La primera molar maxilar tuvo mayor prevalencia de calcificaciones pulpares que la mandibular. La presencia de caries aumentó la posibilidad de aparición de estas calcificaciones, específicamente en maxilar. La CBCT podría ser una herramienta sensible para detectar cálculos pulpares. El conocimiento de la distribución de cálculos pulpares puede ayudar a los dentistas en el tratamiento clínico de endodoncia.

Objectives This study aims to reveal whether and which position of lower third molar (M3), assessed on a 2D image, indicates or potentially exclude the need for the CBCT exploration of the retromolar canal (RMC). We hypothesized that some positions of M3 are associated with overall higher incidence of the RMC, and particularly clinically relevant ones, thus justifying additional CBCT diagnostics. Methods CBCT exam of 186 hemi-mandibles with present M3 were selected for the study. Explorations were made during the 2-year period from January 1th 2018 to December 31th 2019 with Scanora 3Dx Sorodex (Tussula, Finland). The following variables were assessed: the presence and width of the RMC, eruption status, and angulation of the M3. The RMC presence in relation to the M3 eruption status and angulation was analyzed using appropriate statistical tests. Results RMC was present in 89 (47.8%) out of 186 hemi-mandibles. Mean canal width was 1.51 mm. 22.5% of detected canals had the diameter exceeding 2 mm. Third molar's eruption status showed no statistical correlation with the occurrence of RMC. We observed significantly higher occurrence of RMC in the hemi-mandibles containing distally angulated M3 in comparison to other orientations (p = 0.025). Conclusion Based upon our findings, we recommend preoperative CBCT in cases where distal angulation of M3 is observed on 2D images, for the purpose of RMC exploration. Lower resolution CBCT mode and limited field of view (XS or S) are sufficient for the visualization of potentially clinically relevant RMCs, with as much reducing the patient dose.

In this study, a novel anthropomorphic head phantom for quantitative image quality assessment in cone beam computed tomography (CBCT) is proposed. The phantom is composed of tissue equivalent materials (TEMs) which are suitable for cost-efficient fabrication methods such as silicone casting and 3D printing. A monocalcium phosphate/gypsum mixture (MCPHG), nylon and a silyl modified polymer gel (SMP) are proposed as bone, muscle and brain equivalent materials respectively. The TEMs were evaluated for their radiodensity in terms of Hounsfield Units (HU) and their x-ray scatter characteristics. The median radiodensity and inter quartile range (IQR) of the MCPHG and SMP were found to be within the range of the theoretical radiodensity for bone and brain tissue: 922 (IQR = 156) and 47 (IQR = 7) HU respectively. The median radiodensity of nylon was slightly outside of the HU range of muscle tissue, but within the HU range of a combination of muscle and adipose tissue: −18 (IQR = 40) HU. The median ratios between the measured scatter characteristics and simulated tissues were between 0.84 and 1.13 (IQR between 0.05 and 0.14). The preliminary results of this study show that the proposed design and TEMs are potentially suitable for the fabrication of a cost-efficient anthropomorphic head phantom for quantitative image quality assessment in CT or CBCT., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Medical Instruments & Bio-Inspired Technology

This study assesses the accuracy and technical predictability of a computer-guided procedure for harvesting bone from the external oblique ridge using a patient-specific cutting guide. Twenty-two patients needing bone augmentation for implant placement were subjected to mandibular osteotomy employing a case-specific stereolithographic surgical guide generated through computer aided design. Differences between planned and real cut planes were measured comparing pre- and post-operative Cone Beam Computed Tomography images of the donor site according to six validated angular and displacement indexes. Accuracy and technical predictability were assessed for 119 osteotomy planes over the study population. Three different guide fitting approaches were compared. An average root-mean-square discrepancy of 0.52 (0.30–0.97) mm was detected. The accuracy of apical and medial planes was higher than the mesial and distal planes due to occasional antero-posterior guide shift. Fitting the guide with an extra reference point on the closest tooth performed better than using only the bone surface, with two indexes significantly lower and less disperse. The study showed that the surgical plan was actualized with a 1 mm safety margin, allowing effective nerve preservation and reducing technical variability. When possible, surgical guide design should allow fitting on the closest tooth based on both radiological and/or intra-oral scan data.

Despite the considerable experience in mechanical force-induced tooth movement, there still exist several persisting controversies and conflicting opinions about issues crucial for the attainment of excellent results within a reasonable time period for most or all patients. Such controversies embrace the features of (optimal) orthodontic force, its best magnitude and duration, the biology of tooth movement (inflammation and mechanotransduction), biomarkers in oral fluids, best methods for acceleration of tooth movement, and long-term (deleterious) effects of orthodontic treatment. Scientists are discovering that medical care is proving to be as individualized as faces. Each of us is defined by a unique genetic and molecular makeup. This realization is modifying the way diseases are defined and treated and is the basis of a growing movement toward precision medicine, whereby diagnosis and treatment plans are tailored according to a patient's individual needs. Orthodontists are keenly cognizant of the individual variability of their patients, at least functionally and morphologically, and have begun discovering molecular, genetic, and environmental factors that appear to affect the outcome of mechanotherapy. Thus, the way ahead in terms of identifying the biological determinants of tooth movement is clear.

Background. Vocal cord dysfunction (VCD) is characterized by excessive inspiratory closure of the vocal cords leading to breathlessness. Laryngoscopy is the gold standard diagnostic test but cannot be quantified and may be false positive. Recent advent of 320-slice multi-detector CT (320-MDCT) with high temporal resolution as well as isotropic multiplanar and 3-D reconstruction capabilities can provide dynamic assessment of laryngeal and tracheal movement. The aim of this study was to illustrate development of technical and scanning parameters for CT during initial application of this novel imaging modality. Methods. An imaging methodology was devised in patients with suspected VCD referred for dynamic 4-dimensional (4-D) CT. Patients who were unable to lie supine were excluded. Patients were asked to breathe in anormala manner. Dynamic volume CT of the larynx and trachea was done over 16 cm in the Z-axis over 6 seconds. Multi-planar images of 2 mm thickness and 3-D images using volume rendering were viewed in cine mode. Lateral diameter of the vocal cords was measured in axial views using electronic calipers and normalized to tracheal diameter. A diagnostic algorithm was applied (Low et al, AJRCCM, 2011) to generate a curve representing vocal cord width/aperture over time. Results. Dynamic vocal cord, laryngeal and tracheal imaging by 4-D MDCT was feasible. The methodology allowed evaluation of vocal cord movements that could be accurately measured during both inspiration and expiration. Laryngoscopy video images and reconstructed CT images were compared and shown to be concordant (see images on poster). Imaging matched dynamic curves generated by the algorithm (see poster). Conclusion. MDCT is a non-invasive and novel diagnostic tool for assessment of VCD. VCD can be accurately quantified whilst also excluding other disorders (excessive dynamic airway collapse, vocal cord paresis, tracheal stenosis, extrinsic compression). Studies to assess VCD in acute asthma and

BackgroundThe time of flight (TOF) cone beam computed tomography (CBCT) was recently shown to reduce the X-ray scattering effects by 95% and improve the image CNR by 110% for large volume objects. The advancements in X-ray sources like in compact Free Electron Lasers (FEL) and advancements in detector technology show potential for the TOF method to be feasible in CBCT when imaging large objects.ObjectiveTo investigate the feasibility and efficacy of TOF CBCT in imaging smaller objects with different targets such as bones and tumors embedded inside the background.MethodsThe TOF method used in this work was verified using a 24 cm phantom. Then, the GATE software was used to simulate the CBCT imaging of an 8 cm diameter cylindrical water phantom with two bone targets using a modeled 20 keV quasi-energetic FEL source and various TOF resolutions ranging from 1 to 1000 ps. An inhomogeneous breast phantom of similar size with tumor targets was also imaged using the same system setup.ResultsThe same results were obtained in the 24 cm phantom, which validated the applied CBCT simulation approach. For the case of 8 cm cylindrical phantom and bone target, a TOF resolution of 10 ps improved the image contrast-to-noise ratio (CNR) by 57% and reduced the scatter-to-primary ratio (SPR) by 8.63. For the case of breast phantom and tumor target, image CNR was enhanced by 12% and SPR was reduced by 1.35 at 5 ps temporal resolution.ConclusionsThis study indicates that a TOF resolution below 10 ps is required to observe notable enhancements in the image quality and scatter reduction for small objects around 8 cm in diameter. The strong scattering targets such as bone can result in substantial improvements by using TOF CBCT.

Background. Vocal cord dysfunction (VCD) is characterized by excessive inspiratory closure of the vocal cords leading to breathlessness. Laryngoscopy is the gold standard diagnostic test but cannot be quantified and may be false positive. Recent advent of 320-slice multi-detector CT (320-MDCT) with high temporal resolution as well as isotropic multiplanar and 3-D reconstruction capabilities can provide dynamic assessment of laryngeal and tracheal movement. The aim of this study was to illustrate development of technical and scanning parameters for CT during initial application of this novel imaging modality. Methods. An imaging methodology was devised in patients with suspected VCD referred for dynamic 4-dimensional (4-D) CT. Patients who were unable to lie supine were excluded. Patients were asked to breathe in anormala manner. Dynamic volume CT of the larynx and trachea was done over 16 cm in the Z-axis over 6 seconds. Multi-planar images of 2 mm thickness and 3-D images using volume rendering were viewed in cine mode. Lateral diameter of the vocal cords was measured in axial views using electronic calipers and normalized to tracheal diameter. A diagnostic algorithm was applied (Low et al, AJRCCM, 2011) to generate a curve representing vocal cord width/aperture over time. Results. Dynamic vocal cord, laryngeal and tracheal imaging by 4-D MDCT was feasible. The methodology allowed evaluation of vocal cord movements that could be accurately measured during both inspiration and expiration. Laryngoscopy video images and reconstructed CT images were compared and shown to be concordant (see images on poster). Imaging matched dynamic curves generated by the algorithm (see poster). Conclusion. MDCT is a non-invasive and novel diagnostic tool for assessment of VCD. VCD can be accurately quantified whilst also excluding other disorders (excessive dynamic airway collapse, vocal cord paresis, tracheal stenosis, extrinsic compression). Studies to assess VCD in acute asthma and

This study aimed to investigate the factors that could be associated with the risk of labial cortical bone wall perforation with immediate implant placement (IIP) in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. CBCT exams from 126 qualified subjects (756 teeth) were included. Implants were virtually positioned in two different positions: in the long axis of the tooth (prosthetically-driven position) and in an ideal position in relation to adjacent anatomical structures (bone-driven position). Two different implant diameters were planned for each tooth position, namely, 3.75 and 4.3 mm for central incisors and canines, and 3.0 and 3.3 mm for lateral incisors. The incidence of perforation was nearly 80% and 5% for prostheticallyand bone-driven position, respectively. Factors associated with a higher risk of cortical bone wall perforation (bone-driven position), according to logistic regression analysis, were women, wider implants, Sagittal Root Position class IV, and decrease of the labial concavity angle. Perforation of the labial cortical bone wall can be greatly minimized when the implant is placed in a bone-driven position compared to a prosthetically-driven position. It is important to preoperatively evaluate the morphological features of the implant site for risk assessment and to individualize the treatment plan.

This study aimed to investigate the factors that could be associated with the risk of labial cortical bone wall perforation with immediate implant placement (IIP) in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. CBCT exams from 126 qualified subjects (756 teeth) were included. Implants were virtually positioned in two different positions: in the long axis of the tooth (prosthetically-driven position) and in an ideal position in relation to adjacent anatomical structures (bone-driven position). Two different implant diameters were planned for each tooth position, namely, 3.75 and 4.3 mm for central incisors and canines, and 3.0 and 3.3 mm for lateral incisors. The incidence of perforation was nearly 80% and 5% for prostheticallyand bone-driven position, respectively. Factors associated with a higher risk of cortical bone wall perforation (bone-driven position), according to logistic regression analysis, were women, wider implants, Sagittal Root Position class IV, and decrease of the labial concavity angle. Perforation of the labial cortical bone wall can be greatly minimized when the implant is placed in a bone-driven position compared to a prosthetically-driven position. It is important to preoperatively evaluate the morphological features of the implant site for risk assessment and to individualize the treatment plan.

BackgroundThe time of flight (TOF) cone beam computed tomography (CBCT) was recently shown to reduce the X-ray scattering effects by 95% and improve the image CNR by 110% for large volume objects. The advancements in X-ray sources like in compact Free Electron Lasers (FEL) and advancements in detector technology show potential for the TOF method to be feasible in CBCT when imaging large objects.ObjectiveTo investigate the feasibility and efficacy of TOF CBCT in imaging smaller objects with different targets such as bones and tumors embedded inside the background.MethodsThe TOF method used in this work was verified using a 24 cm phantom. Then, the GATE software was used to simulate the CBCT imaging of an 8 cm diameter cylindrical water phantom with two bone targets using a modeled 20 keV quasi-energetic FEL source and various TOF resolutions ranging from 1 to 1000 ps. An inhomogeneous breast phantom of similar size with tumor targets was also imaged using the same system setup.ResultsThe same results were obtained in the 24 cm phantom, which validated the applied CBCT simulation approach. For the case of 8 cm cylindrical phantom and bone target, a TOF resolution of 10 ps improved the image contrast-to-noise ratio (CNR) by 57% and reduced the scatter-to-primary ratio (SPR) by 8.63. For the case of breast phantom and tumor target, image CNR was enhanced by 12% and SPR was reduced by 1.35 at 5 ps temporal resolution.ConclusionsThis study indicates that a TOF resolution below 10 ps is required to observe notable enhancements in the image quality and scatter reduction for small objects around 8 cm in diameter. The strong scattering targets such as bone can result in substantial improvements by using TOF CBCT.

Background: The objective of this study was to measure two parameters involved in tri-dimensional implant plan‑ ning: the position of the buccal and palatal bone wall and the palatal thickness. Methods: Cone beam computed tomography (CBCT) images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to Decem‑ ber 2014. The height diference between the palatal and buccal walls was measured on the most coronal point of both walls. The thickness of the palatal wall was measured 2 mm from the most coronal point of the palatal wall. Results: The mean values in the maxilla were 1.7±0.9 mm for central and lateral incisors, 2.2±1.7 mm for canines, 1.6±0.9 mm for premolars and 1.9±1.5 mm for molars. In the lower jaw, the mean values were 1.3±0.8 mm for inci‑ sors, 1.7±1.2 mm for canines, 2.3±1.3 mm for premolars, and 2.6±1.7 mm for molars. In the upper jaw, more than 55% of maxillary teeth (excluding second premolars and molars) presented mean height diferences greater than 1 mm. In the mandible, more than 60% of incisors showed a buccal bone thickness of 1 mm from the apical to lingual aspect. All teeth except the second premolar presented a buccal wall located more than 1 mm more apically than the lingual bone wall. Conclusions: The buccal bone wall is located more apically (greater than 1 mm) than the palatal or lingual table in most of the cases assessed. The thickness of the palatal or lingual table is also less than 2 mm in the maxilla and man‑ dible, except in the upper canines and premolars and the lower molars.

The dental follicle (DF) is the tissue that surrounds the crown of the developing tooth. In X-ray, images it appears as a radiolucent area. The removal of an impacted mandibular third molar is a common procedure in oral surgery. The radiographic evidence of pathology, commonly defined as a pericoronal radiolucency measuring at least mm 2.5 mm in any dimension, is accepted for the extraction of impacted mandibular third molars. Mesioangular impactions are usually more closely placed to the inferior alveolar canal, and the use of cone beam computer tomography (CBCT) before the removal of impacted mandibular third molars has been reported to be appropriate in these cases. The aim of this study was to evaluate the microscopic features of radiographically normal DFs associated with mesioangular impacted mandibular third molars examined through CBCT. Thirteen mesioangular impacted third molars from ten patients (5 males and 5 females, mean age +/- SD: 15.1 +/- 1.66) with a maximum width of the DF <2.5 mm, as digitally established by CBCT, were included in this study. All the DFs associated with the removed third molars were examined histologically through the analysis of different variables. The mean (+/- SD) and range of the maximum width of the DFs were 1.35 (+/- 0.47) mm and 0.71-2.21 mm, respectively. Nine (69.23%) DFs showed odontogenic remnants, five (38.46%) showed focal squamous metaplasia and eight (61.53%) mild mesenchymal myxoid degeneration. The maximum width of the DF failed to show any significant correlation with all the histological variables considered in this study. Aware of the limited number of patients included in this study, the histo-radiographic correlation in our case series confirm data in the literature, according to which normal pericoronal imaging may be associated with DF tissue changes/variations that in turn are potentially associated with the development of pathologies including odontogenic cysts and tumors. Whether these changes/variat, De två första författarna delar förstaförfattarskapet.

The dental follicle (DF) is the tissue that surrounds the crown of the developing tooth. In X-ray, images it appears as a radiolucent area. The removal of an impacted mandibular third molar is a common procedure in oral surgery. The radiographic evidence of pathology, commonly defined as a pericoronal radiolucency measuring at least mm 2.5 mm in any dimension, is accepted for the extraction of impacted mandibular third molars. Mesioangular impactions are usually more closely placed to the inferior alveolar canal, and the use of cone beam computer tomography (CBCT) before the removal of impacted mandibular third molars has been reported to be appropriate in these cases. The aim of this study was to evaluate the microscopic features of radiographically normal DFs associated with mesioangular impacted mandibular third molars examined through CBCT. Thirteen mesioangular impacted third molars from ten patients (5 males and 5 females, mean age +/- SD: 15.1 +/- 1.66) with a maximum width of the DF <2.5 mm, as digitally established by CBCT, were included in this study. All the DFs associated with the removed third molars were examined histologically through the analysis of different variables. The mean (+/- SD) and range of the maximum width of the DFs were 1.35 (+/- 0.47) mm and 0.71-2.21 mm, respectively. Nine (69.23%) DFs showed odontogenic remnants, five (38.46%) showed focal squamous metaplasia and eight (61.53%) mild mesenchymal myxoid degeneration. The maximum width of the DF failed to show any significant correlation with all the histological variables considered in this study. Aware of the limited number of patients included in this study, the histo-radiographic correlation in our case series confirm data in the literature, according to which normal pericoronal imaging may be associated with DF tissue changes/variations that in turn are potentially associated with the development of pathologies including odontogenic cysts and tumors. Whether these changes/variat, De två första författarna delar förstaförfattarskapet.

The dental follicle (DF) is the tissue that surrounds the crown of the developing tooth. In X-ray, images it appears as a radiolucent area. The removal of an impacted mandibular third molar is a common procedure in oral surgery. The radiographic evidence of pathology, commonly defined as a pericoronal radiolucency measuring at least mm 2.5 mm in any dimension, is accepted for the extraction of impacted mandibular third molars. Mesioangular impactions are usually more closely placed to the inferior alveolar canal, and the use of cone beam computer tomography (CBCT) before the removal of impacted mandibular third molars has been reported to be appropriate in these cases. The aim of this study was to evaluate the microscopic features of radiographically normal DFs associated with mesioangular impacted mandibular third molars examined through CBCT. Thirteen mesioangular impacted third molars from ten patients (5 males and 5 females, mean age +/- SD: 15.1 +/- 1.66) with a maximum width of the DF <2.5 mm, as digitally established by CBCT, were included in this study. All the DFs associated with the removed third molars were examined histologically through the analysis of different variables. The mean (+/- SD) and range of the maximum width of the DFs were 1.35 (+/- 0.47) mm and 0.71-2.21 mm, respectively. Nine (69.23%) DFs showed odontogenic remnants, five (38.46%) showed focal squamous metaplasia and eight (61.53%) mild mesenchymal myxoid degeneration. The maximum width of the DF failed to show any significant correlation with all the histological variables considered in this study. Aware of the limited number of patients included in this study, the histo-radiographic correlation in our case series confirm data in the literature, according to which normal pericoronal imaging may be associated with DF tissue changes/variations that in turn are potentially associated with the development of pathologies including odontogenic cysts and tumors. Whether these changes/variat, De två första författarna delar förstaförfattarskapet.

Background: The objective of this study was to measure two parameters involved in tri-dimensional implant plan‑ ning: the position of the buccal and palatal bone wall and the palatal thickness. Methods: Cone beam computed tomography (CBCT) images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to Decem‑ ber 2014. The height diference between the palatal and buccal walls was measured on the most coronal point of both walls. The thickness of the palatal wall was measured 2 mm from the most coronal point of the palatal wall. Results: The mean values in the maxilla were 1.7±0.9 mm for central and lateral incisors, 2.2±1.7 mm for canines, 1.6±0.9 mm for premolars and 1.9±1.5 mm for molars. In the lower jaw, the mean values were 1.3±0.8 mm for inci‑ sors, 1.7±1.2 mm for canines, 2.3±1.3 mm for premolars, and 2.6±1.7 mm for molars. In the upper jaw, more than 55% of maxillary teeth (excluding second premolars and molars) presented mean height diferences greater than 1 mm. In the mandible, more than 60% of incisors showed a buccal bone thickness of 1 mm from the apical to lingual aspect. All teeth except the second premolar presented a buccal wall located more than 1 mm more apically than the lingual bone wall. Conclusions: The buccal bone wall is located more apically (greater than 1 mm) than the palatal or lingual table in most of the cases assessed. The thickness of the palatal or lingual table is also less than 2 mm in the maxilla and man‑ dible, except in the upper canines and premolars and the lower molars.

The dental follicle (DF) is the tissue that surrounds the crown of the developing tooth. In X-ray, images it appears as a radiolucent area. The removal of an impacted mandibular third molar is a common procedure in oral surgery. The radiographic evidence of pathology, commonly defined as a pericoronal radiolucency measuring at least mm 2.5 mm in any dimension, is accepted for the extraction of impacted mandibular third molars. Mesioangular impactions are usually more closely placed to the inferior alveolar canal, and the use of cone beam computer tomography (CBCT) before the removal of impacted mandibular third molars has been reported to be appropriate in these cases. The aim of this study was to evaluate the microscopic features of radiographically normal DFs associated with mesioangular impacted mandibular third molars examined through CBCT. Thirteen mesioangular impacted third molars from ten patients (5 males and 5 females, mean age +/- SD: 15.1 +/- 1.66) with a maximum width of the DF <2.5 mm, as digitally established by CBCT, were included in this study. All the DFs associated with the removed third molars were examined histologically through the analysis of different variables. The mean (+/- SD) and range of the maximum width of the DFs were 1.35 (+/- 0.47) mm and 0.71-2.21 mm, respectively. Nine (69.23%) DFs showed odontogenic remnants, five (38.46%) showed focal squamous metaplasia and eight (61.53%) mild mesenchymal myxoid degeneration. The maximum width of the DF failed to show any significant correlation with all the histological variables considered in this study. Aware of the limited number of patients included in this study, the histo-radiographic correlation in our case series confirm data in the literature, according to which normal pericoronal imaging may be associated with DF tissue changes/variations that in turn are potentially associated with the development of pathologies including odontogenic cysts and tumors. Whether these changes/variat, De två första författarna delar förstaförfattarskapet.

Background: To estimate whether there is skeletal and/or dental asymmetry in class II subdivision patients, between the Class II side and the Class I side using of cone beam computed tomography (CBCT). Material and Methods: A sample of 30 patients, from a private clinic, retrospectively selected; with a class II sub division diagnosis requiring treatment, who underwent wide-field CBCT that met the inclusion criteria. The data was processed with Dolphin 3D version 11.95 Premium software. The craniometric points, as well as the spatial orientation scheme of the three-dimensional model were proposed by Craig Minich, et al. (1) Results: The Class II subdivision side and the Class I side of each patient were compared through intramaxillary, intramandibular, and intermaxillary measurements, evaluating each one in three dimensions (sagittal, frontal, and axial). Also, the measurements made from the three-dimensional volume, were contrasted with those generated in the biplane views. The level of significance used was 0.05. Statistical analysis was performed using the R program (R Development Core Team), version 3.4.4. The intraoperative variability was previously verified using the Dahl berg formula. This error is 0.35 -1.10, so the spatial orientation and placement of craniometric points are repeatable and reliable. Conclusions: Statistically significant differences have been found with respect to skeletal values and dentoalveolar position. Regarding the skeletal findings, the class II subdivision side is narrower and there is a shortening of the condylar branch. In the dentoalveolar position on this side, the upper molar and canine are in an advanced position, the lower molar is posterior and lower than the contralateral and the lower canine is in a delayed position. Further more, measurements made from a two-dimensional image cannot be extrapolated with those made directly from a three-dimensional volume. The problem is generated by a deviation in dental position as well

Background: The objective of this study was to measure two parameters involved in tri-dimensional implant plan‑ ning: the position of the buccal and palatal bone wall and the palatal thickness. Methods: Cone beam computed tomography (CBCT) images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to Decem‑ ber 2014. The height diference between the palatal and buccal walls was measured on the most coronal point of both walls. The thickness of the palatal wall was measured 2 mm from the most coronal point of the palatal wall. Results: The mean values in the maxilla were 1.7±0.9 mm for central and lateral incisors, 2.2±1.7 mm for canines, 1.6±0.9 mm for premolars and 1.9±1.5 mm for molars. In the lower jaw, the mean values were 1.3±0.8 mm for inci‑ sors, 1.7±1.2 mm for canines, 2.3±1.3 mm for premolars, and 2.6±1.7 mm for molars. In the upper jaw, more than 55% of maxillary teeth (excluding second premolars and molars) presented mean height diferences greater than 1 mm. In the mandible, more than 60% of incisors showed a buccal bone thickness of 1 mm from the apical to lingual aspect. All teeth except the second premolar presented a buccal wall located more than 1 mm more apically than the lingual bone wall. Conclusions: The buccal bone wall is located more apically (greater than 1 mm) than the palatal or lingual table in most of the cases assessed. The thickness of the palatal or lingual table is also less than 2 mm in the maxilla and man‑ dible, except in the upper canines and premolars and the lower molars.

Background: To estimate whether there is skeletal and/or dental asymmetry in class II subdivision patients, between the Class II side and the Class I side using of cone beam computed tomography (CBCT). Material and Methods: A sample of 30 patients, from a private clinic, retrospectively selected; with a class II sub division diagnosis requiring treatment, who underwent wide-field CBCT that met the inclusion criteria. The data was processed with Dolphin 3D version 11.95 Premium software. The craniometric points, as well as the spatial orientation scheme of the three-dimensional model were proposed by Craig Minich, et al. (1) Results: The Class II subdivision side and the Class I side of each patient were compared through intramaxillary, intramandibular, and intermaxillary measurements, evaluating each one in three dimensions (sagittal, frontal, and axial). Also, the measurements made from the three-dimensional volume, were contrasted with those generated in the biplane views. The level of significance used was 0.05. Statistical analysis was performed using the R program (R Development Core Team), version 3.4.4. The intraoperative variability was previously verified using the Dahl berg formula. This error is 0.35 -1.10, so the spatial orientation and placement of craniometric points are repeatable and reliable. Conclusions: Statistically significant differences have been found with respect to skeletal values and dentoalveolar position. Regarding the skeletal findings, the class II subdivision side is narrower and there is a shortening of the condylar branch. In the dentoalveolar position on this side, the upper molar and canine are in an advanced position, the lower molar is posterior and lower than the contralateral and the lower canine is in a delayed position. Further more, measurements made from a two-dimensional image cannot be extrapolated with those made directly from a three-dimensional volume. The problem is generated by a deviation in dental position as well

The dental follicle (DF) is the tissue that surrounds the crown of the developing tooth. In X-ray, images it appears as a radiolucent area. The removal of an impacted mandibular third molar is a common procedure in oral surgery. The radiographic evidence of pathology, commonly defined as a pericoronal radiolucency measuring at least mm 2.5 mm in any dimension, is accepted for the extraction of impacted mandibular third molars. Mesioangular impactions are usually more closely placed to the inferior alveolar canal, and the use of cone beam computer tomography (CBCT) before the removal of impacted mandibular third molars has been reported to be appropriate in these cases. The aim of this study was to evaluate the microscopic features of radiographically normal DFs associated with mesioangular impacted mandibular third molars examined through CBCT. Thirteen mesioangular impacted third molars from ten patients (5 males and 5 females, mean age +/- SD: 15.1 +/- 1.66) with a maximum width of the DF <2.5 mm, as digitally established by CBCT, were included in this study. All the DFs associated with the removed third molars were examined histologically through the analysis of different variables. The mean (+/- SD) and range of the maximum width of the DFs were 1.35 (+/- 0.47) mm and 0.71-2.21 mm, respectively. Nine (69.23%) DFs showed odontogenic remnants, five (38.46%) showed focal squamous metaplasia and eight (61.53%) mild mesenchymal myxoid degeneration. The maximum width of the DF failed to show any significant correlation with all the histological variables considered in this study. Aware of the limited number of patients included in this study, the histo-radiographic correlation in our case series confirm data in the literature, according to which normal pericoronal imaging may be associated with DF tissue changes/variations that in turn are potentially associated with the development of pathologies including odontogenic cysts and tumors. Whether these changes/variat, De två första författarna delar förstaförfattarskapet.

The use of an imaging modality, such as cone beam computed tomography (CBCT) for verification and target location immediately prior to a radiotherapy fraction, is essential in modern radiotherapy.Image-guided radiotherapy (IGRT) enables assessment and control of uncertainties in patient positioning, reveals internal organ motion and deformation, and paves the way towards adaptive radiotherapy (ART). However, using CBCT images as an imaging modality leads to an additional radiation dose burden for patients.The aim of this master thesis was to optimize CBCT acquisition and reconstruction protocols with regard to image quality and dose for treatments in the head and neck and pelvic regions, and to analyze the trend of specific imaging parameters. A second goal was to check long-term stability of the radiation output of a selected imaging protocol.If the image quality is optimized, the visualization of anatomical details and the accuracy of the image guidance can be improved. Nevertheless, it is very challenging to find a compromise between better image quality and lower dose for the patients. An improvement in image quality usually results in higher exposure and much longer acquisition and reconstruction time of the image data, which is not beneficial for the patients.By using an F1 filter in the head and neck regions, the dose burden for patients can be reduced by approximately 40 % (average value of two LINACs). The image quality is also slightly improved by the exchanged filter, as a slightly higher SNR could be determined, which is desirable. Therefore, an implementation of an imaging protocol with this filter into clinical routine should be considered.In the pelvic regions, a dose reduction can be achieved by increasing the gantry speed when taking CBCT images. Although the results showed a slightly lower image quality, the faster rotation of the gantry provides better patient comfort, as the time on the treatment table can be reduced by almost one minute. Patient

Model-based learned iterative reconstruction methods have recently been shown to outperform classical reconstruction algorithms. Applicability of these methods to large scale inverse problems is however limited by the available memory for training and extensive training times, the latter due to computationally expensive forward models. As a possible solution to these restrictions we propose a multi-scale learned iterative reconstruction scheme that computes iterates on discretisations of increasing resolution. This procedure does not only reduce memory requirements, it also considerably speeds up reconstruction and training times, but most importantly is scalable to large scale inverse problems with non-trivial forward operators, such as those that arise in many 3D tomographic applications. In particular, we propose a hybrid network that combines the multi-scale iterative approach with a particularly expressive network architecture which in combination exhibits excellent scalability in 3D. Applicability of the algorithm is demonstrated for 3D cone beam computed tomography from real measurement data of an organic phantom. Additionally, we examine scalability and reconstruction quality in comparison to established learned reconstruction methods in two dimensions for low dose computed tomography on human phantoms., QC 20210302.QC 20210318.

Model-based learned iterative reconstruction methods have recently been shown to outperform classical reconstruction algorithms. Applicability of these methods to large scale inverse problems is however limited by the available memory for training and extensive training times, the latter due to computationally expensive forward models. As a possible solution to these restrictions we propose a multi-scale learned iterative reconstruction scheme that computes iterates on discretisations of increasing resolution. This procedure does not only reduce memory requirements, it also considerably speeds up reconstruction and training times, but most importantly is scalable to large scale inverse problems with non-trivial forward operators, such as those that arise in many 3D tomographic applications. In particular, we propose a hybrid network that combines the multi-scale iterative approach with a particularly expressive network architecture which in combination exhibits excellent scalability in 3D. Applicability of the algorithm is demonstrated for 3D cone beam computed tomography from real measurement data of an organic phantom. Additionally, we examine scalability and reconstruction quality in comparison to established learned reconstruction methods in two dimensions for low dose computed tomography on human phantoms.

The aim of this study was to quantify sub-resolution trabecular bone morphometrics, which are also related to osteoarthritis (OA), from clinical resolution cone beam computed tomography (CBCT). Samples (n = 53) were harvested from human tibiae (N = 4) and femora (N = 7). Grey-level co-occurrence matrix (GLCM) texture and histogram-based parameters were calculated from CBCT imaged trabecular bone data, and compared with the morphometric parameters quantified from micro-computed tomography. As a reference for OA severity, histological sections were subjected to OARSI histopathological grading. GLCM and histogram parameters were correlated to bone morphometrics and OARSI individually. Furthermore, a statistical model of combined GLCM/histogram parameters was generated to estimate the bone morphometrics. Several individual histogram and GLCM parameters had strong associations with various bone morphometrics (|r| > 0.7). The most prominent correlation was observed between the histogram mean and bone volume fraction (r = 0.907). The statistical model combining GLCM and histogram-parameters resulted in even better association with bone volume fraction determined from CBCT data (adjusted R2 change = 0.047). Histopathology showed mainly moderate associations with bone morphometrics (|r| > 0.4). In conclusion, we demonstrated that GLCM- and histogram-based parameters from CBCT imaged trabecular bone (ex vivo) are associated with sub-resolution morphometrics. Our results suggest that sub-resolution morphometrics can be estimated from clinical CBCT images, associations becoming even stronger when combining histogram and GLCM-based parameters.

Purpose: Cone beam computed tomography (CBCT) is an important imaging technique in maxillofacial evaluations. However, application-specific image analysis methods aimed at extracting quantitative information from these images need to be further developed. The aim of this study was to provide a robust and objective method that could assess radiologic changes around dental implants after sinus elevation surgery with simultaneous implant placement. Materials and Methods: The study was performed retrospectively on patients fulfilling the inclusion criteria. The included patients had been CBCT scanned preoperatively, at baseline (early after surgery), and 6 months postoperatively. In order to quantify the radiologic changes, an image analysis workflow was developed based on the postoperative baseline and 6-month scans. The workflow included metal artifact reduction, registration, and a standardized protocol for semiautomatic segmentation. Validation of different steps of the method was conducted by comparing scans from all time points. Comparison of constant volumes (eg, screws and bony parts not subjected to change) was used. Additionally, the Dice similarity coefficient (DSC) was used to measure the overlap of the segmentations. Results: The study included nine maxillary sinuses from six patients. The bone formation was quantified and visualized in 3D. In the validation, no significant differences were found for the constant volumes at the different scanning time points. The DSC showed accurate results with values > 0.92. Conclusion: The method presented in this study provides an objective and robust evaluation of bone formation around dental implants. The same methodologies can be applied in other studies of dental CBCT images, eg, for comparison of grafting materials or surgical strategies.

Objectives: To compare the symptomatology of patients with maxillary sinusitis of dental origin (MSDO) with sinusitis due to upper respiratory tract infection (URTI) with a special focus on time to correct diagnosis. To define the accuracy of cone beam computed tomography (CBCT) in detecting the dental origin of the sinusitis. Methods: Retrospective review of the otolaryngology specialist care, primary health care and dental health care medical records of patients with maxillary sinusitis who has been referred for radiology. All patients were examined by CBCT, which has a better resolution regarding bony structures than low-dose computed tomography. To the best of our knowledge there is no previous study on this topic based on CBCT as diagnostic method. Results: Sixty-one patients were included in the study; of these, 25 had MSDO and 36 had URTI sinusitis. The MSDO patients more frequently reported foul odour and foul taste than patients with URTI sinusitis. The URTI sinusitis patients more frequently reported symptoms such as facial pain, facial congestion and cold-related symptoms. Both the time from the onset of symptoms to the first medical visit and the subsequent time to a correct diagnosis were significantly longer in the MSDO group. The accuracy of CBCT for detecting dental pathology as the underlying cause of sinusitis was 97%. Conclusion: The present study verifies that maxillary sinusitis of dental origin differs from viral-induced rhinosinusitis concerning symptomatology and clinical findings. Certain findings and symptoms could serve as valuable indicators of an underlying dental pathology, because although MSDO is well known, the present study shows that these patients are often misdiagnosed and the correct diagnose and treatment is often delayed several months. Consequently, better assessment is important. The suspicion of MSDO should be raised for patients with unilateral sinusitis presenting little pain, foul odour or foul taste and a long time cour

Aim: To gain insight into the decision processes of dentists when requesting a cone beam computed tomography (CBCT) examination in endodontic settings. Methodology: Fourteen dentists (eight female) 33-58 years of age (mean = 44) practising in Sweden were interviewed. Ten of the dentists were specialists in Endodontics. The absolute inclusion criterion was experience of referring patients for CBCT for endodontic reasons. The included dentists comprised a strategically selected diverse sample in terms of gender, age, work experience, educational background, location of practice, service affiliation and accessibility to CBCT. Data were obtained through semistructured interviews exposing the context of their last three self-reported referrals. Dentists were encouraged to describe their experiences of the circumstances in their own words, aided by the interviewer's open-ended questions. The interviews were audio-recorded and transcribed verbatim. The text was analysed by qualitative content analysis. Results: The manifest content was organized into three categories that were defined as visualization as a desire, facilitating tough decisions and allocating responsibility. Conclusion: An overall theme (covering the latent content) was identified: A balance between clinical common sense and a 'better safe than sorry' attitude guides the use of CBCT in endodontic settings. Informants had high clinical standards, knowledge concerning radiation risks and good sense, which could compensate for their lack of knowledge of guidelines. The national radiation regulatory system was perceived to work as a slightly porous gatekeeper for over-usage.

Objectives: To compare the symptomatology of patients with maxillary sinusitis of dental origin (MSDO) with sinusitis due to upper respiratory tract infection (URTI) with a special focus on time to correct diagnosis. To define the accuracy of cone beam computed tomography (CBCT) in detecting the dental origin of the sinusitis. Methods: Retrospective review of the otolaryngology specialist care, primary health care and dental health care medical records of patients with maxillary sinusitis who has been referred for radiology. All patients were examined by CBCT, which has a better resolution regarding bony structures than low-dose computed tomography. To the best of our knowledge there is no previous study on this topic based on CBCT as diagnostic method. Results: Sixty-one patients were included in the study; of these, 25 had MSDO and 36 had URTI sinusitis. The MSDO patients more frequently reported foul odour and foul taste than patients with URTI sinusitis. The URTI sinusitis patients more frequently reported symptoms such as facial pain, facial congestion and cold-related symptoms. Both the time from the onset of symptoms to the first medical visit and the subsequent time to a correct diagnosis were significantly longer in the MSDO group. The accuracy of CBCT for detecting dental pathology as the underlying cause of sinusitis was 97%. Conclusion: The present study verifies that maxillary sinusitis of dental origin differs from viral-induced rhinosinusitis concerning symptomatology and clinical findings. Certain findings and symptoms could serve as valuable indicators of an underlying dental pathology, because although MSDO is well known, the present study shows that these patients are often misdiagnosed and the correct diagnose and treatment is often delayed several months. Consequently, better assessment is important. The suspicion of MSDO should be raised for patients with unilateral sinusitis presenting little pain, foul odour or foul taste and a long time cour

Objectives: To compare the symptomatology of patients with maxillary sinusitis of dental origin (MSDO) with sinusitis due to upper respiratory tract infection (URTI) with a special focus on time to correct diagnosis. To define the accuracy of cone beam computed tomography (CBCT) in detecting the dental origin of the sinusitis. Methods: Retrospective review of the otolaryngology specialist care, primary health care and dental health care medical records of patients with maxillary sinusitis who has been referred for radiology. All patients were examined by CBCT, which has a better resolution regarding bony structures than low-dose computed tomography. To the best of our knowledge there is no previous study on this topic based on CBCT as diagnostic method. Results: Sixty-one patients were included in the study; of these, 25 had MSDO and 36 had URTI sinusitis. The MSDO patients more frequently reported foul odour and foul taste than patients with URTI sinusitis. The URTI sinusitis patients more frequently reported symptoms such as facial pain, facial congestion and cold-related symptoms. Both the time from the onset of symptoms to the first medical visit and the subsequent time to a correct diagnosis were significantly longer in the MSDO group. The accuracy of CBCT for detecting dental pathology as the underlying cause of sinusitis was 97%. Conclusion: The present study verifies that maxillary sinusitis of dental origin differs from viral-induced rhinosinusitis concerning symptomatology and clinical findings. Certain findings and symptoms could serve as valuable indicators of an underlying dental pathology, because although MSDO is well known, the present study shows that these patients are often misdiagnosed and the correct diagnose and treatment is often delayed several months. Consequently, better assessment is important. The suspicion of MSDO should be raised for patients with unilateral sinusitis presenting little pain, foul odour or foul taste and a long time cour