Measurement of buccolingual inclination of posterior teeth and the curve of Wilson in patients with different sagittal skeletal patterns using cone-beam computed tomography / 口腔疾病防治

Objective@# To study the buccolingual inclination of posterior premolars and molars and the curve of Wilson in patients with different sagittal skeletal patterns, to explore the compensation mechanism of horizontal inclination of posterior teeth in patients with different sagittal skeletal patterns and to provide a reference for the control of posterior tooth inclination in the treatment of bone malocclusion.@*Methods@#This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Ninety CBCT scans of adults and ninety scans of adolescents before orthodontic treatment were evaluated in this cross-sectional study. There were 30 skeletal Class I, Class Ⅱ, and Class Ⅲ patients in the adult group and adolescent group. The inclination angles of posterior teeth and the curve of Wilson of first and second molars were measured, and data were analyzed between adolescents and adults with different sagittal skeletal patterns.@*Results @#Compared with skeletal Class Ⅰ adult patients, the upper posterior molar inclination of skeletal Class Ⅱ patients was significantly lower, and the lower posterior molar inclination was significantly higher. Compared with skeletal ClassⅠ adult patients, the upper posterior molar inclination of skeletal Class Ⅲ adult patients was higher, and the lower posterior molar inclination was significantly lower. The Wilson curve of the second molar in skeletal Class Ⅱ adult patients was significantly higher than that in the other groups. Compared with skeletal ClassⅠ adolescent patients, skeletal Class Ⅲ adolescent patients had a significantly higher upper posterior molar inclination; however, no difference was found between the inclination of the posterior teeth between skeletal Class Ⅰ, Class Ⅱ and Class Ⅲ adolescent patients. Comparing adolescent and adult samples, in skeletal Class Ⅱ patients, adults showed more lingual inclination than adolescents in the upper posterior teeth and less lingual inclination in the lower posterior teeth except for the mandibular first molar. Comparing adolescent and adult samples, in skeletal Class Ⅲ patients, adults showed more lingual inclination than adolescents in the lower posterior teeth except for the mandibular second molars and showed no difference in the upper posterior teeth.@*Conclusions@#The inclination of the posterior teeth and the curve of Wilson show significant differences between the three sagittal skeletal patterns. Compared with those of skeletal Class Ⅰ patients, the posterior teeth of skeletal Class Ⅱ patients show more lingual inclination in the upper arch and less lingual inclination in the lower arch. Meanwhile, posterior teeth of skeletal Class Ⅲ patients show more lingual inclination in the lower arch and maintain the inclination in the upper arch.

Importance of Dental Radiography in Forensic Odontology: A Review

Introduction: Forensic odontology is an important and evolving branch. It has been established for critical issues like medi- colegal cases and identification of a dead person. Radiographic assisted documentation will provide objective information including the precise recording of the uniqueness of every individual where it has been used extensively in dental identification based on anatomy and by comparing maxillofacial skeletal landmarks in antemortem and post mortem records. Main body: Human Identification is mainly based on a dead body decomposition state. More likely of missing persons and the identification of individuals in conditions like criminal investigations and mass disasters. Odontological method for human identification is used commonly as it is simple by comparing with other methods, but complex in execution and requires skills and expertise. There are so many radiological techniques for forensic purposes like Computer tomography, cone-beam com- puter tomography, Orthopantomogram, 3D facial reconstruction, Radiovisiography, and Virtopsy. Objectives: This review highlights the different radiographic techniques and procedures and its application in forensic odon- tology. Source search criteria: Data were obtained and analyzed from previously published literature and electronic database search- es of relevant published literature from PubMed and Google Scholarfrom the 2001 to 2021 year. Conclusion: Imaging technologies and radiographs have become a vital component of modern medical practice and foren- sic odontology. The application of any of the mentioned techniques depends on the availability of previous images, data, or skeletal findings for Identification. So forensic radiology has a potential for crime-solving and is useful in conventional dental identification based on anatomy and by comparing maxillofacial skeletal landmarks in antemortem and post-mortem records, as they have become a crucial part of dental practice as well as in forensic odontology for diagnosis of disease, treatment plan- ning, identification of tooth structures, and age estimation.

Tooth and pulp chamber automatic segmentation with artificial intelligence network and morphometry method in cone-beam CT / Segmentación automática de cámaras dentales y pulpares con red de inteligencia artificial y método de morfometría en TC de haz cónico

SUMMARY: This study aims to extract teeth and alveolar bone structures in CBCT images automatically, which is a key step in CBCT image analysis in the field of stomatology. In this study, semantic segmentation was used for automatic segmentation. Five marked classes of CBCT images were input for U-net neural network training. Tooth hard tissue (including enamel, dentin, and cementum), dental pulp cavity, cortical bone, cancellous bone, and other tissues were marked manually in each class. The output data were from different regions of interest. The network configuration and training parameters were optimized and adjusted according to the prediction effect. This method can be used to segment teeth and peripheral bone structures using CBCT. The time of the automatic segmentation process for each CBCT was less than 13 min. The Dice of the evaluation reference image was 98 %. The U-net model combined with the watershed method can effectively segment the teeth, pulp cavity, and cortical bone in CBCT images. It can provide morphological information for clinical treatment.

RESUMEN: El objetivo del presente estudio fue extraer estructuras dentarias y óseas alveolares desde imágenes CBCT automáticamente, lo cual es un paso clave en el análisis de imágenes CBCT en el campo de la estomatología. En este estudio, se utilizó la segmentación de tipo emántica para la segmentación automática. Se ingresaron cinco clases de imágenes CBCT marcadas, para el entrenamiento de la red neuronal U-net. El tejido duro del diente (incluidos esmalte, dentina y cemento), la cavidad de la pulpa dentaria, hueso cortical, hueso esponjoso y otros tejidos se marcaron manualmente en cada clase. Los datos se obtuvieron de diferentes regiones de interés. La configuración de la red y los parámetros de entrenamiento se optimizaron y ajustaron de acuerdo con un análisis predictivo. Este método se puede utilizar para segmentar dientes y estructuras óseas periféricas mediante CBCT. El tiempo del proceso de segmentación automática para cada CBCT fue menor a 13 min. El "Dice" de evaluación de la imagen de referencia fue de 98 %. El modelo U-net combinado con el método "watershed"puede segmentar eficazmente los dientes, la cavidad pulpar y el hueso cortical en imágenes CBCT. Puede proporcionar información morfológica para el tratamiento clínico.

Caracterización de la mineralización del proceso estilohioideo en tomografías computarizadas volumétricas / Characterization of the mineralization of the stylohyoid process in volumetric computed tomography

RESUMEN Objetivo: Analizar las características tomográficas de la mineralización del proceso estilohioideo (MPE) mediante tomografía computarizada volumétrica (TCV). Material y Métodos: Se revisaron 860 tomografías computarizadas volumétricas (593 corresponden al sexo femenino y 267 al sexo masculino) de un servicio de Radiología Bucal y Maxilofacial. El rango etario estuvo comprendido entre 6 a 89 años. Se utilizó la adecuación tomográfica de la clasificación de Langlais. El análisis estadístico se realizó mediante el uso de la prueba chi-cuadrado. Resultados: Se encontraron 289 MPE, prevaleció la mineralización bilateral (68.86%). La longitud promedio aritmética de las MPE fue de 39.54 mm. La frecuencia de la MPE fue del 33.60% (289 casos). Se encontró mayor frecuencia en el grupo etario de 40 a 49 años, no hubo diferencia significativa entre el sexo femenino y masculino (p=0.53). En la clasificación de Langlais el tipo más frecuente fue la variante segmentado con 42.2%. El patrón de MPE más frecuente fue la variantes parcialmente calcificada con 58.8%. Conclusiones: La frecuencia de la MPE fue de 33.60% y la TCV permite identificar oportunamente esta variación anatómica.

SUMMARY Objective: To evaluate the tomographic characteristics of the mineralization of the stylohyoid process by volumetric computed tomography (CT). Material and Methods: reviewed 860 volumetric computed tomographies (593 correspond to the female sex and 267 to the male sex) of the Oral and Maxillofacial Radiology Service. The age range was between 6 to 89 years. The tomographic adequacy of the Langlais classification was used. The statistical analysis was performed using the chi-square test. Results: 289 MPE were found, bilateral mineraliza-tion prevailed (68.86%). The arithmetic average length of the MPE was 39.54 mm. The frequency of MPE was 33.60% (289 cases). It was found more frequently in the age group of 40 to 49 years, there was no significant difference between the female and male sex (p = 0.5367). In the classification of Langlais the most frequent type was the segmented variants with 42.2%. The most frequent MPE pattern was the partially calcified variants with 58.8%. Conclusions: The frequency of the MPE was 33.60% and the TCV allows to identify this anatomical variation in a timely manner.

Comparing the effects of fast and slow expansion on nasal cavity and maxilla structure / 华西口腔医学杂志

OBJECTIVE@#This study aims to compare the effects of fast and slow expansion on nasal cavity structure.@*METHODS@#A total of 40 patients were selected and randomly divided into two groups. Cone-beam computer tomography (CBCT) was obtained before and after surgery and used for comparing the changes in nasal structure before and after treatment.@*RESULTS@#Fast expansion had resulted in greater changes in the basilar and nasal bone arch extension structures than slow expansion. No significant difference at maxillary width and nasal parenchyma.@*CONCLUSIONS@#Rapid expansion therapy has more beneficial effects on nasal function.

Diagnóstico, planificación del tratamiento y endodoncia de un primer premolar inferior con dos canales mediante tomografía computarizada 3D: reporte de un caso

El tratamiento endodóntico debe considerar que los dientes presentan una morfología del sistema de canales radiculares con alta variabilidad y complejidad. por lo tanto, el conocimiento acabado de la anatomía radicular y la planificación del procedimiento utilizando sistemas imagenológicos previos a la realización del tratamiento endodóntico, como la tomografía computarizada 3D (CBTC), mejoran el pronóstico, aumentando las probabilidades de éxito. el objetivo de este reporte es mostrar la secuencia de una resolución clínica de un primer premolar inferior (diente 4.4) con una anatomía compleja, utilizando el CBTC tanto en el diagnóstico como en la planificación.

Compound odontoma: a case report and literature review / 口腔疾病防治

@#Odontoma is one of the most common odontogenic tumors in the jaws, and it is widely considered as tooth hamartomas. This article reports a rare compound odontoma with 39 denticles which was checked and diagnosed radically by CBCT, and relevant literatures are reviewed.

Compound odontoma: a case report and literature review / 口腔疾病防治

@#Odontoma is one of the most common odontogenic tumors in the jaws, and it is widely considered as tooth hamartomas. This article reports a rare compound odontoma with 39 denticles which was checked and diagnosed radically by CBCT, and relevant literatures are reviewed.

A comparison between root canal deviations after root preparation using two kinds of nickel-titanium instruments / 安徽医科大学学报

Objective To evaluate the root canal deviations in vitro teeth curved root with TF and Protaper instru-ments by cone beam computer tomography( CBCT) . Methods 40 teeth in vitro in the standard collection were ran-domly assigned to two groups, prepared with the crown-down method, the TF group ready to 0. 06/#25; the Pro-taper group ready to F2 . CBCT scans were taken to measure the mesial and distal thicknesses of the tube wall in vitro teeth before and after preparation. The root canal deviation and the rate of shaft center were measured with ref-erence to the formula proposed by Gambill. Results The TF group need less time in preparation and has more effi-ciency(P<0. 05) than the Protaper group; both TF and Protaper devices appeared deformation after 5 root canal preparations in average, no instruments broken. Comparing the offset of the internal and external wall of root canal in 3, 5, 7 mm from the apex, the root canal deviation prepared by the TF group was less than the Protaper group, and its rate of axis center was greater than the Protaper group, closer to 1. Conclusion TF can maintain original root canal morphology in preparing curved root canal, also has higher efficiency;under the noninvasive condition, the root canal forming ability of preparation instruments can be evaluated by CBCT.

The skeletal morphology of temporomandibular joints in patients with unilateral posterior scissors bite by using cone-beam computed tomography / 重庆医学

Objective To analyze the skeletal characteristics of temporomandibular joint in patients with unilateral posterior scis-sors bite by using the cone-beam computed tomography(CBCT) .Methods Thirty-five patients of Angle class Ⅰ were scanned by CBCT (19 cases with unilateral scissors bite as the experimental group and 16 cases without scissors bite as the control group ) The CT images were reconstructed into 3D computer models by using the Dental Volume Reformat Function of the Ondemand 3D pack-age .9 anatomical landmarks were located and all data of 11 measured value were statistically analyzed .Results There were statisti-cal differences in the skeletal characteristics of temporomandibular joint in the scissors-bite side of the experimental group compared with those in the non-scissors-bite side (P0 .05) .There were statistical significances in the skeletal characteris-tics of temporomandibular joint of the controlled group compared with those in the scissors-bite side of the experimental group ,and the same with those in the non-scissors-bite side (P<0 .01) .Conclusion The CBCT is an effective tool to analyze the skeletal char-acteristics of temporomandibular joint characteristics .There were differences in the morphology of the condyle and the glenoid fossa of patients with unilateral posterior scissors bite .

Avaliação da efetividade de um guia radiográfico-cirúrgico mediante tomografia computadorizada / CBCT evaluation of a radiographic surgical guide for placement miniscrews into the interradicular bone

Os mini-implantes ortodônticos têm comprovado sua eficiência clínica provendo uma ancoragem absoluta, estes dispositivos podem ser instalados sobre pequenos espaços de tecido ósseo, mas devem ser inseridos efetuando uma técnica cirúrgica muito precisa. Devido ao alto índice de contatos radiculares verificado na literatura científica pela utilização clínica dos mini-implantes, surgiu o interesse para estudar mediante tomografia computadorizada, o posicionamento tridimensional de mini-implantes ortodônticos inseridos através de um guia radiográfico-cirúrgico (RAAG). Foram considerados dois grupos neste estudo, o grupo experimental (GE) prospectivo que incluiu um total de 21 pacientes, 14 pacientes do sexo feminino e 7 do sexo masculino, com 18 anos em média. Neste grupo foram inseridos 21 parafusos ortodônticos auto-perfurantes (POAF) com diâmetro de 1.4mm e 8.0mm de comprimento por um mesmo profissional e utilizou-se um guia radiográfico-cirúrgico Ring Accupunture Auricular Guide (RAAG) com diâmetro de 3.0mm. No grupo controle (Gc) retrospectivo foram inseridos 25 (POAF) na maxila sem nenhum tipo de guia radiográfico-cirúrgico, este grupo controle (Gc) incluiu 10 pacientes do sexo feminino e 15 do sexo masculino com 18 anos em média, cada um dos POAF foi instalado por diferentes profissionais. Após a inserção dos POAF todos os 46 pacientes foram submetidos a Tomografia Dental Computadorizada mediante o Tomógrafo ICAT CONE BEAM. Para a comparação entre os grupos de estudados neste ensaio, foram utilizados os testes Kruskall Wallis e “t” de Student. O grupo experimental GE apresentou uma porcentagem de 88% de inserção equidistante de POAF, evidenciando significância estatística em relação ao grupo Gc. O lado direito do grupo experimental GE apresentou melhor posicionamento dos POAF, evidenciando significância estatística em relação ao lado esquerdo do mesmo GE. Os grupos controle Gc1 e Gc2 apresentaram 100% falhas de posicionamento dos POAF, em relação ao centro...

Introduction: Orthodontic Mini-Screws Self Drilling (ODMS) has proven to be effective providing an efficient absolute anchorage. It could be placed in restricted sites, but requiring a precise surgical technique. Recently (ODMS) have become more popular, thus problems has emerged for example; root contact, would lead to perforation or cause other root injuries. However, no systematic study has evaluated the tridimensional position of (ODMS) into the alveolar process, thus in order to diminish iatrogenic root damage a rapid insertion radiographic surgical guide (RAAG) was proposed to place (ODMS) precisely in the interradicular bone. A specific tomography software was used to evaluated the tridimensional position of (ODMS) and its inaccuracy was estimated

Avaliação da efetividade de um guia radiográfico-cirúrgico mediante tomografia computadorizada / CBCT evaluation of a radiographic surgical guide for placement miniscrews into the interradicular bone

Os mini-implantes ortodônticos têm comprovado sua eficiência clínica provendo uma ancoragem absoluta, estes dispositivos podem ser instalados sobre pequenos espaços de tecido ósseo, mas devem ser inseridos efetuando uma técnica cirúrgica muito precisa. Devido ao alto índice de contatos radiculares verificado na literatura científica pela utilização clínica dos mini-implantes, surgiu o interesse para estudar mediante tomografia computadorizada, o posicionamento tridimensional de mini-implantes ortodônticos inseridos através de um guia radiográfico-cirúrgico (RAAG). Foram considerados dois grupos neste estudo, o grupo experimental (GE) prospectivo que incluiu um total de 21 pacientes, 14 pacientes do sexo feminino e 7 do sexo masculino, com 18 anos em média. Neste grupo foram inseridos 21 parafusos ortodônticos auto-perfurantes (POAF) com diâmetro de 1.4mm e 8.0mm de comprimento por um mesmo profissional e utilizou-se um guia radiográfico-cirúrgico Ring Accupunture Auricular Guide (RAAG) com diâmetro de 3.0mm. No grupo controle (Gc) retrospectivo foram inseridos 25 (POAF) na maxila sem nenhum tipo de guia radiográfico-cirúrgico, este grupo controle (Gc) incluiu 10 pacientes do sexo feminino e 15 do sexo masculino com 18 anos em média, cada um dos POAF foi instalado por diferentes profissionais. Após a inserção dos POAF todos os 46 pacientes foram submetidos a Tomografia Dental Computadorizada mediante o Tomógrafo ICAT CONE BEAM. Para a comparação entre os grupos de estudados neste ensaio, foram utilizados os testes Kruskall Wallis e “t” de Student. O grupo experimental GE apresentou uma porcentagem de 88% de inserção equidistante de POAF, evidenciando significância estatística em relação ao grupo Gc. O lado direito do grupo experimental GE apresentou melhor posicionamento dos POAF, evidenciando significância estatística em relação ao lado esquerdo do mesmo GE. Os grupos controle Gc1 e Gc2 apresentaram 100% falhas de posicionamento dos POAF, em relação ao centro...

Introduction: Orthodontic Mini-Screws Self Drilling (ODMS) has proven to be effective providing an efficient absolute anchorage. It could be placed in restricted sites, but requiring a precise surgical technique. Recently (ODMS) have become more popular, thus problems has emerged for example; root contact, would lead to perforation or cause other root injuries. However, no systematic study has evaluated the tridimensional position of (ODMS) into the alveolar process, thus in order to diminish iatrogenic root damage a rapid insertion radiographic surgical guide (RAAG) was proposed to place (ODMS) precisely in the interradicular bone. A specific tomography software was used to evaluated the tridimensional position of (ODMS) and its inaccuracy was estimated