Exploratory analysis of new craniometric measures for the investigation of biological sex using open-access statistical and machine-learning tools on a cone-beam computed tomography sample.

Investigation of the biological sex of human remains is a crucial aspect of physical anthropology. However, due to varying states of skeletal preservation, multiple approaches and structures of interest need to be explored. This research aims to investigate the potential use of distances between bifrontal breadth (FMB), infraorbital foramina distance (IOD), nasal breadth (NLB), inter-canine width (ICD), and distance between mental foramina (MFD) for combined sex prediction through traditional statistical methods and through open-access machine-learning tools. Ethical approval was obtained from the ethics committee, and out of 100 cone beam computed tomography (CBCT) scans, 54 individuals were selected with all the points visible. Ten extra exams were chosen to test the predictors developed from the learning sample. Descriptive analysis of measurements, standard deviation, and standard error were obtained. T-student and Mann-Whitney tests were utilized to assess the sex differences within the variables. A logistic regression equation was developed and tested for the investigation of the biological sex as well as decision trees, random forest, and artificial neural networks machine-learning models. The results indicate a strong correlation between the measurements and the sex of individuals. When combined, the measurements were able to predict sex using a regression formula or machine learning based models which can be exported and added to software or webpages. Considering the methods, the estimations showed an accuracy rate superior to 80% for males and 82% for females. All skulls in the test sample were accurately predicted by both statistical and machine-learning models. This exploratory study successfully established a correlation between facial measurements and the sex of individuals, validating the prediction potential of machine learning, augmenting the investigative tools available to experts with a high differentiation potential.

Effect of a metal artifact reduction algorithm on dehiscence and fenestration detection around zirconia implants with cone beam computed tomography.

OBJECTIVE: To assess the efficacy of the metal artifact reduction algorithm (MARA) of the Cranex 3D cone beam computed tomography (CBCT) device in the detection of peri-implant dehiscence and fenestration around zirconia implants. STUDY DESIGN: In total, 60 implants were placed in bovine ribs. Dehiscence and fenestration defects were created around the implants, after which 60 CBCT images were obtained with and 60 without activation of MARA. Three radiologists examined the images for the presence of defects. The area under the curve (AUC) from receiver operating characteristic analysis, sensitivity, and specificity were calculated to assess the ability to discriminate the presence vs absence of bone defects. One-way analysis of variance was employed to analyze outcome measures. The significance level was established at 5% (α = 0.05). RESULTS: AUC values indicated excellent discrimination of dehiscence on images with MARA activation and an excellent to outstanding range of discrimination with MARA deactivation. For fenestration, MARA activation and deactivation both led to outstanding discrimination. Sensitivity and specificity values revealed that activation of MARA was helpful in distinguishing the presence vs. absence of dehiscence, while both MARA conditions were helpful for fenestration. However, there were no statistically significant differences between MARA activation and deactivation for any outcome measure (P >.05). CONCLUSION: CBCT is suitable for detecting peri-implant defects, but MARA application does not significantly affect peri-implant dehiscence and fenestration detection.

Deep learning driven segmentation of maxillary impacted canine on cone beam computed tomography images.

The process of creating virtual models of dentomaxillofacial structures through three-dimensional segmentation is a crucial component of most digital dental workflows. This process is typically performed using manual or semi-automated approaches, which can be time-consuming and subject to observer bias. The aim of this study was to train and assess the performance of a convolutional neural network (CNN)-based online cloud platform for automated segmentation of maxillary impacted canine on CBCT image. A total of 100 CBCT images with maxillary canine impactions were randomly allocated into two groups: a training set (n = 50) and a testing set (n = 50). The training set was used to train the CNN model and the testing set was employed to evaluate the model performance. Both tasks were performed on an online cloud-based platform, 'Virtual patient creator' (Relu, Leuven, Belgium). The performance was assessed using voxel- and surface-based comparison between automated and semi-automated ground truth segmentations. In addition, the time required for segmentation was also calculated. The automated tool showed high performance for segmenting impacted canines with a dice similarity coefficient of 0.99 ± 0.02. Moreover, it was 24 times faster than semi-automated approach. The proposed CNN model achieved fast, consistent, and precise segmentation of maxillary impacted canines.

Influence of Apical Patency on the Adaptation of the Master Filling Cone: A Cone-beam Computed Tomography Assessment.

Introduction: This study aimed to evaluate if the apical patency can influence the adaptation of the master cone of gutta-percha, quantifying the volume of voids and areas at the last 2 mm of the working length (WL). Materials and Methods: Sixty distobuccal canals of extracted upper molars were divided into 3 groups (n=20) based on the patency length (A: passed 1 mm beyond the apical foramen (AF), B: at the AF and C: 1 mm short of the AF) with the Easy ProDesign Logic 25/0.01 file. Each group was subdivided into 2 subgroups (n=10) based on the WL established to prepare the root canal (1: 1 mm short of the AF or 2: at the AF) with the Easy ProDesign Logic 25/0.05 file. After the scan, void volumes were calculated from the last 2 mm of the WL and void areas at 0 mm, 1 mm and 2 mm of the last of WL, as well as the relation between the tip and taper of the master cone with the amount of void volume and areas. To investigate statistically significant differences, we used the Kruskal-Wallis statistical test. Results: There were more voids in volume when patency was achieved 1 mm beyond the AF and the root canal preparation was conducted at 1mm short of the AF (A1 group). Furthermore, the same group showed more voids areas, mainly on the last millimeter of WL. Conclusion: Achieving apical patency at 1 mm beyond the AF followed by instrumentation 1 mm short of the AF created more voids between the master gutta-percha cone and the root canal wall, especially on the last millimeter of WL.

Morphometry and Morphology of the Articular Surfaces of the Medial Region of the Temporomandibular Joint in the Felis Catus (Domestic cat) - A Cone Beam Computed Tomography Study.

The articular surfaces of the temporomandibular joint (TMJ) in the cat consist of the articular head of the condylar process of the ramus of the mandible and the mandibular fossa of the petrous part of the temporal bone. Anatomic conformation of the TMJ articular surfaces can vary; however, this has not been studied in the cat. Thus, the aim of this study was to characterize the conformation of the medial region of the TMJ in mesocephalic adult cats as well as to determine the articular relationship by measurement of the degree of coverage of the mandibular fossa over the articular head. This was accomplished by assessing 60 TMJs from 30 mesocephalic adult cats by means of cone-beam computed tomography (CBCT). The width and depth of the mandibular fossa, and the degree of coverage of the mandibular fossa were evaluated using parasagittal reconstructions of the medial aspect of the TMJ by two observers. No statistically significant difference was observed during the intra and interobserver evaluation of the mandibular fossa width and depth and the degree of coverage of the mandibular fossa over the articular head. P-values for the studied variables were greater than 0.05. The resulting measurements demonstrated a concave mandibular fossa with a prominent retroarticular process and a poorly developed articular eminence; a well-defined rounded articular surface, and a high degree of coverage (171°) of the mandibular fossa over the articular head. In conclusion, the articular surfaces at the medial aspect of the TMJ displayed elevated geometric similarity, with an articular head of the condylar process deeply seated in the mandibular fossa.

Cone-beam computed tomography analysis of degenerative changes, condylar excursions and positioning and possible correlations with temporomandibular disorder signs and symptoms

Aim: To describe cone-beam computed tomography (CBCT) features in patients with temporomandibular disorders (TMDs), in terms of degenerative changes, condylar excursions and positioning as well as their possible correlations with signs and symptoms. Methods: Clinical records of patients diagnosed with TMD who were seen between January 2018 and December 2019 were retrospectively evaluated. These patients were divided into the following groups based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD): arthralgia, myalgia, and arthralgia and myalgia groups. The CBCT examination findings of the patients were evaluated in relation to degenerative changes, estimates of condylar excursion, and condylar positioning. The likelihood ratio test was used to verify the possible differences among the three groups, whereas the chi-square test was used to verify the possible differences among the signs and symptoms for the tomographic findings (p ≤ 0.050). Results: In this study, 65 patients with TMD were included. These patients were predominantly female (84.6%) with a mean age of 40.6 years. Tomographic findings of flattening, hyperexcursion and posterior condylar positioning were frequent. A significant correlation was noted between osteophyte and lateral capsule pain (p = 0.027), erosion and posterior capsule pain (p = 0.026), and flattening, pseudocysts (p < 0.050) and condylar excursion (p < 0.001) with mouth opening. Conclusion: Few correlations were noted between degenerative changes and signs of joint pain as well as degenerative changes and condylar hypoexcursion with mouth opening. These correlations were likely associated with division by diagnosis, whereas condylar positioning did not correlate with signs and symptoms

Reference standard thickness for bone plates of upper teeth: an ultra-high-resolution study using tomographic mapping / Padrão de referência de espessura para cristas ósseas de dentes superiores: um estudo de ultra-alta resolução usando mapeamento tomográfico

Objective: it is important to know the thicknesses of the alveolar bone plates (ABPs) based on the current literature for the planning and success of orthodontic treatment. However, studies have scientific limitations regarding ABPs as the image resolution is not adequate and is restricted to a few teeth or buccal face only. This study was aimed at reporting a reference standard for bone plates of upper teeth, in which 15 patients (mean age of 21.79 years) with balanced occlusion and a harmonious facial profile were evaluated using cone-beam computed tomography at a voxel size of 0.1 mm. Material and Methods: bone tissues of the cervical, middle, and apical thirds of the root (buccal and palatal), the distance between cement-enamel junction (CEJ) and alveolar bone crest (ABC), and inclination of the teeth to the palatal plane were evaluated. Paired t-test, Spearman's correlation tests, and linear regression tests were used (P < 0.05). Results: the buccal distance between the CEJ and ABC was greater than the palatal one in all pairs of teeth. Most of the bone tissues had a thickness ≤ 1 mm in the buccal face, whereas in the cervical-apical direction, the thickness was ≥ 2 mm. There is no equivalence between genders in the sample. Conclusion: the reduced buccal bone architecture around the first premolars was indicative of local gingival recessions, and the lack of gender uniformity was suggestive of individual evaluation. References of normal bone tissue determining the orthodontic limits were provided to assist in the treatment planning. (AU)

Objetivo: é importante conhecer as espessuras das cristas ósseas alveolares (COAs) com base na literatura atual para o planejamento e sucesso do tratamento ortodôntico. No entanto, os estudos apresentam limitações científicas em relação às COAs, pois a resolução da imagem não é adequada e está restrita apenas a alguns dentes ou face vestibular. Este estudo teve como objetivo descrever um padrão de referência para corticais ósseas de dentes superiores, no qual 15 pacientes (idade média de 21,79 anos) com oclusão equilibrada e perfil facial harmonioso foram avaliados por meio de tomografia computadorizada de feixe cônico no tamanho de voxel de 0,1 mm. Material e Métodos: os tecidos ósseos dos terços cervical, médio e apical da raiz (vestibular e palatina), a distância entre a junção cemento-esmalte (JCE) e a crista óssea alveolar (COA) e a inclinação dos dentes ao plano palatino foram avaliados. Foram utilizados o teste t pareado, os testes de correlação de Spearman e os testes de regressão linear (P < 0,05). Resultados: a distância vestibular entre a JEC e a COA foi maior que a palatina em todos os pares de dentes. A maioria dos tecidos ósseos apresentou espessura ≤ 1 mm na face vestibular, enquanto no sentido cérvico-apical a espessura foi ≥ 2 mm. Não há equivalência entre os gêneros na amostra. Conclusão: a arquitetura óssea vestibular reduzida ao redor dos primeiros pré-molares foi indicativa de recessões gengivais locais, e a falta de uniformidade de gênero foi sugestiva de avaliação individual. Referências de tecido ósseo normal determinando os limites ortodônticos foram fornecidas para auxiliar no planejamento do tratamento. (AU)

Alterações dimensionais de maxilas portadoras de caninos impactados / Dimensional changes of maxillas with impacted canines

O objetivo do estudo foi avaliar medidas do arco superior realizadas em imagens por Tomografia Computadorizada de Feixe Cônico (TCFC) de pacientes com caninos impactados localizados por vestibular e palatino. Método: A amostra consistiu de imagens axiais de TCFC de 63 pacientes de ambos os sexos (44 do sexo feminino e 19 do masculino) com média de idade de 17,8 anos. Empregou-se software OnDemand® 3D para obter as medidas de distância intermolar, perímetro e comprimento maxilar. Inicialmente, foi realizada análise descritiva e exploratória dos dados. Foi aplicado teste t de Student para comparar os dois grupos com canino impactado uni e bilateralmente e análise de variância (ANOVA) para comparar os grupos, quanto à posição do canino impactado, por vestibular ou palatino. A reprodutibilidade entre as medidas foi avaliada pelo coeficiente de correlação intraclasse (ICC), considerado o nível de significância de 5% Resultados: Pôde-se verificar que do total de voluntários, 39 indivíduos apresentavam caninos impactados unilateralmente e 24 bilateralmente. Desses, 26 apresentavam-se na posição vestibular e 37 na posição palatina. Observou-se que a distância intermolares foi significativamente menor no grupo com canino impactado bilateralmente (p<0,05), o perímetro e o comprimento do arco maxilar não diferiram significativamente entre os pacientes com caninos impactados unilateral ou bilateralmente (p>0,05). Porém esses parâmetros se apresentaram significativamente menores (p<0,05) nos pacientes com canino impactados na posição palatina. Conclusões: Maxilas com caninos impactados bilateralmente apresentam distância intermolar menor e caninos impactados por palatino estão presentes em maxilas com o menor perímetro de arco.(AU)

Objective: The purpose of the study was to evaluate measurements of the upper arch performed by Cone Beam Computed Tomography (CBCT) images of patients with impacted canines located in the vestibular and palatal areas. Method: The sample consisted of axial CBCT images of 63 patients of both genders (44 female and 19 male) with a mean age of 17.8 years. OnDemand® 3D software was used to obtain the measurements of intermolar distance, perimeter and maxillary length. Initially, descriptive and exploratory data analysis was performed. Student t test was applied to compare the two groups with unilaterally and bilaterally impacted canines, and analysis of variance (ANOVA) was used to compare the groups regarding the position the impacted canine, either vestibular or palatal. Reproducibility between measurements was evaluated by the intraclass correlation coefficient (ICC), considering the level of significance of 5%. Results: It was possible to verify that of the total number of volunteers, 39 individuals had unilaterally and 24 bilaterally impacted canines. Of these, 26 were in the vestibular position and 37 in the palatal position. It was observed that the intermolar distance was significantly smaller in the group with bilaterally impacted canines (p<0.05), the perimeter and maxillary arch length did not differ significantly among patients with unilaterally or bilaterally impacted canines (p>0.05). However, these parameters were significantly lower (p<0.05) in patients with impacted canines in the palatal position. Conclusions: Maxillas with bilaterally impacted canines present smaller intermolar distance, and palatal canines impacted are present in maxillary with the smallest arch perimeter.(AU)

Facial soft tissue depth measurements in cone-beam computed tomography: A study of a Brazilian sample.

Forensic facial reconstruction (approximation) (FFR) is an aid to human identification when no presumed identity is available. It is based on average soft tissue thickness (STT) applied onto a skull. These averages vary at each landmark according to sex, ancestry, and Facial Growth Patterns (FGP). To obtain the reference, there are different protocols and conditions, such as needles in cadavers, ultrasound, magnetic resonance, and computer tomography. Using cone-beam computed tomography (CBCT), landmark placement and direction of measurement are critical. The purpose of this article is to detailly describe a method for STT measurement in CBCT DICOM files and to test it in the analysis of a multi-ancestral Brazilian sample, subdivided into sex, age and FGP. A sample of 100 (50 male and 50 female) CBCT exams were selected and the volume was primarily been repositioned to cephalometric standards. A detailed description of the location and measurement direction of 32 landmarks was provided and granted good reproducibility of the measurements. The averages were assessed by sex, age, and FGP. There were significant differences between males and females. The CBCT measuring protocol provided standardization of measurements and is a method to be used in future researches. Advantages of CBCT, such as the subject's upright position and adjustable volume positioning, also justify its usage. Limited differences of STT were related to age and FGP. The updated Brazilian soft tissue thickness chart is a reliable source of data for forensic and clinical purposes.

Guided Endodontic Access in a Calcified Central Incisor: A Conservative Alternative for Endodontic Therapy.

Guided endodontic access is a promising method to treat teeth with pulp calcification. This report aimed to describe a case of root canal treatment performed through guided endodontic access in a calcified anterior tooth with apical periodontitis. A 23-year-old female with a history of trauma 10 years ago in the anterior maxilla was referred to the dental office. Her chief complaint was discolouration of the left central incisor crown. The tooth was sensitive to percussion and responded negatively to pulp sensitivity tests. The periapical radiography showed pulp calcification and periapical radiolucency. Cone-beam computed tomography (CBCT) was obtained to allow a more detailed view of the pulp canal and the periapical area. An intraoral scan was performed and the standard tessellation language (STL) archive was combined with digital imaging and communications on medicine (DICOM) images from CBCT in the Implant Viewer software. Subsequently, a 3D model was designed and printed to guide the endodontic access in position and appropriate angulation for dental instrumentation. The mold was positioned on the patient's tooth and the root canal treatment was performed. After two years, complete healing of periapical tissues was observed. This method facilitates the drill targeting during access, reducing the risk of deviations and perforations.

Occurrence of nonarticular incidental findings on panoramic radiographs in painful temporomandibular disorders / Ocurrencia de hallazgos incidentales no articulares en ortopantomografias en los trastornos temporomandibulares dolorosos

Facial pain is one of the symptoms of temporomandibular disorders (TMDs) but can be associated with other pathological conditions. The present study retrospectively evaluated the occurrence of nonarticular incidental findings in panoramic radiographs in a group of patients with painful TMDs. Outpatients with a diagnosis of TMD were included and distributed into three groups: arthralgia, myalgia or arthralgia and myalgia, according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Nonarticular incidental findings of their panoramic radiographs were classified in relation to pathological, dental and endodontic status. The dependency relationships among the variables were analyzed using the likelihood test. Sixty patients (38 women and 22 men; mean age: 36.9 years) were evaluated. There was a predominance of arthralgia plus disc displacement (43.4 %), followed by myopain plus arthralgia and disc displacement (38.3 %) and myopain (18.3 %). Pathologic radiographic changes such as bone loss, caries, maxillary sinus opacification and periapical lesions were frequent. Dental alterations such as the absence and altered position of teeth and impacted teeth were frequent. Endodontic changes such as periapical lesions with or without endodontic treatment were frequent. There was no significant difference between groups except for gyroversion. The incidental findings were compatible with caries, sinusitis, impacted tooth and periapical lesion, which may be associated with orofacial pain and could potentially be superimposed on the initial diagnosis, although this hypothesis was discarded. Findings such as the absence and altered position of teeth were also frequent, which may represent occlusal factors associated with TMDs.

El dolor orofacial es uno de los síntomas de los trastornos temporomandibulares (TTM), pero puede estar asociado con otras afecciones patológicas. El presente estudio evaluó retrospectivamente la aparición de hallazgos incidentales no articulares a través de ortopantomografías en un grupo de pacientes con TTM dolorosas. Se incluyeron pacientes con diagnóstico de TTM y se distribuyeron en tres grupos: artralgia, mialgia o artralgia y mialgia, de acuerdo con los criterios de diagnóstico para los trastornos temporomandibulares (DC/TMD). Los hallazgos incidentales no articulares de las ortopantomografias se clasificaron en relación al estado patológico, dental y endodóncico. Las relaciones de dependencia entre las variables se analizaron mediante la prueba de probabilidad. Fueron evaluados 60 pacientes (38 mujeres y 22 hombres; edad media: 36,9 años). Hubo predominio de artralgia más desplazamiento de disco (43,4 %), seguido de mialgia más artralgia y desplazamiento de disco (38,3 %) y mialgia (18,3 %). Las alteraciones radiográficas patológicas como pérdida ósea, carie dentaria, opacificación del seno maxilar y lesiones periapicales fueron frecuentes. Entre las alteraciones dentales, las impactaciones, malposiciones o ausencias dentarias fueron frecuentes. Entre las alteraciones endodóncicas, las lesiones periapicales frecuentes. No hubo diferencias significativas entre los grupos, excepto para la girosversión dentaria. Los hallazgos incidentales fueron compatibles con carie dentaria, sinusitis, diente impactado y lesión periapical, lo que podría estar asociado con el dolor orofacial y así estar sobrepuesto en el diagnóstico inicial, aunque esta hipótesis fue descartada. Hallazgos como la ausencia y la posición alterada de los dientes también fueron frecuentes, lo que puede representar factores oclusales asociados con TTM.

Evaluation of cervical peri-implant optical density in longitudinal control of immediate implants in the anterior maxilla region.

OBJECTIVE: This research aimed to longitudinally evaluate the optical density of peri-implant alveolar bone. The data acquired from study participants previously treated with 37 osseointegrated implants were analyzed utilizing the radiographic subtraction technique. METHODS AND MATERIALS: The radiographic follow-ups were performed five times: at the implantation of the prostheses and after 15, 90, 180 and 360 days. Intraoral radiographs were obtained by the paralleling technique using individualized Hanshin-type positioners to guarantee the standardization of the images. The obtained digital images were aligned and equalized before they were submitted to the radiographic subtraction procedure. RESULTS: A significant difference was found between the distal region of Group I (patients treated with osseointegrated implants who required extraction of the dental element) and the 360 day follow-up and the distal region of Group II (patients with healed alveolar sockets) in all follow-up analyses (p < 0.05). We did not observe a significant difference between the groups analyzed and other follow-ups concerning the subcrestal and middle third regions for both the mesial and distal variables (p > 0.05). There was a statistically significant difference in the distal sites [χ2 = 5,745,, p = 0.03], showing a significant association between time and the presence of bone resorption. This association was not shown on the mesial surface (p = 0.16). CONCLUSION: We concluded that there was no statistically significant difference between groups I and II. Using this technique, we were able to quantitatively and qualitatively evaluate the changes in the proximal sites on the digital radiographic images for the analyzed data. Digital subtraction technology to measure peri-implant bone density is an accurate and reproducible technique for quantifying peri-implant bone reactions to different therapeutic modalities.

The Frontal Sinus Cavity Exhibits Sexual Dimorphism in 3D Cone-beam CT Images and can be Used for Sex Determination.

Few studies have assessed the use of the frontal sinus cavities for sex differentiation. In this study, a new methodology was used to assess the reliability of CBCT images of the frontal sinus cavity for determining sex based on the sexual dimorphism found in this anatomical structure. The survey sample consisted of 130 scans that were reconstructed three-dimensionally. 3D images of the cavity volume in the frontal, lateral, and basal views were exported in TIFF. The following variables were measured in a second program: area, perimeter, bounding rectangle, ellipse fit, circularity, aspect ratio, roundness, solidity, and Feret's diameter. The methodology demonstrated the existence of sexual dimorphism with an accuracy of 80.0% in the logistic regression model. The basal view had the greatest explanatory power in the final model. This methodology may be used as an alternative way of determining a reliable biological profile during the analysis of skeletal remains.

Assessment of treatment outcomes for facial prostheses in patients with craniofacial defects: A pilot retrospective study.

STATEMENT OF PROBLEM: The longevity of silicone facial prostheses is short, and published data concerning this type of rehabilitation are limited. PURPOSE: The purpose of this retrospective study was to identify predictive variables for prosthetic failure and to highlight the results that can be expected after treatment with silicone facial prostheses. MATERIAL AND METHODS: After institutional approval, patient records from a single Brazilian institution for the time period 2004 to 2015 were assessed. A standardized form was used to collect patient data. Frailty survival modeling (simple random effects survival model) was used to test whether age, sex, type of prosthesis, source of defect, number of implants, and type of retention have a direct impact on the prosthetic failure rate (α=.05). RESULTS: Auricular prostheses were the most frequently fabricated prostheses. Eighty-four prostheses were fabricated during the follow-up period. The overall survival rate for facial prostheses was 34.5%. Color alteration was the most common reason for new prostheses (27.38%). The implant success rate was 98.18%. The number of implants approached statistical significance (P=.06) with a reduced risk of failure when the patient had 2 implants compared with patients with zero implants and patients with more than 2 implants. CONCLUSIONS: Patients should be recalled frequently so that retouches can be performed, avoiding the repeated fabrication of new prostheses. Well-designed studies are necessary to identify more relevant complications and factors that lead to prosthetic failure.

Guidelines for reproducing geometrical aspects of intra-oral radiographs images on cone-beam computed tomography.

Human identification requires comparison of individual traits of a person, depending on the availability and reproduction of antemortem (AM) records. If there is no presumed identity or AM exams are not available for comparison, the production of postmortem (PM) records is impaired. The purpose of this research is to describe and test standards to enable the comparison of antemortem periapical radiographs to images extracted from the manipulation of postmortem CBCT exams in multiple identification simulations in a randomized blind study. In a simulation, 20 CBCT images from dry skulls were used as PM records and 3 periapical radiographs (total of 60) that were randomized and blinded from the first examiner. In each case, an intentional incidence error of 10° was added in four different directions. Three points were selected in the AM radiograph, and the angle, linear measurements and proportion between these distances were collected. The AM data were used to mathematically find similar image geometry on a CBCT maximum intensity projection. Possible identification by superimposition was achieved in all cases, and statistical analysis proved the success in the reproduction of angular and length proportion using CBCT incidence manipulation. Significant reproducibility was also observed on intra- and inter-observer tests. In conclusion, the images extracted from CBCT could be compared to any periapical radiographs by superimposition, providing acceptable evidence to establish human identification. The application of this protocol is suitable for forensic practices with the high level of reproducibility and could be used as PM record when no AM records are available at the time of the exam.

Clinical and Histomorphometric Evaluation of Fresh Frozen Bone Allograft in Sinus Lift Surgery.

PURPOSE: The aim of this prospective clinical study was to evaluate the clinical and histomorphometric data of newly formed bone tissue from fresh frozen human allograft in sinus lift surgery. PATIENTS AND METHODS: Thirty-three sinus lift procedures were performed in 20 patients, divided into two groups. The control group (n = 8) received autogenous bone from the mandibular ramus, and the experimental group (n = 12) received fresh frozen bone (FFB) allograft in chips. After 6 months, 52 implants were placed and 50 biopsies were collected for histomorphometric analysis. Cone beam computed tomography scans were performed at preoperative, immediate postoperative, and delayed postoperative time intervals to assess the degree of graft volume loss. RESULTS: There was no statistically significant difference between groups as regards degree of graft volume loss (p = .983), total bone area (p = .191), remaining particles (p = .348), and proportion of active osteoblasts (p = .867). There was a statistically significant difference in the vitality rate between the groups (p = .043). In both groups, all implants were clinically osseointegrated after 4 months. CONCLUSION: FFB allograft was shown to be a feasible substitute for autogenous bone graft in sinus lift surgery.

Human identification through frontal sinus 3D superimposition: Pilot study with Cone Beam Computer Tomography.

As a unique anatomical feature of the human body, the frontal sinus morphology has been used for identification of unknown bodies with many techniques, mostly using 2D postero-anterior X-rays. With the increase of the use of Cone-Beam Computer Tomography (CBCT), the availability of this exam as ante-mortem records should be considered. The purpose of this study is to establish a new technique for frontal sinus identification through direct superimposition of 3D volumetric models obtained from CBCT exam, by testing two distinct situations. First, a reproducibility test, where two observers independently rendered models of frontal sinus from a sample 20 CBCT exams and identified them on each other's list. In the second situation, one observer tested the protocol and established on different exams of three individual. Using the open source DICOM viewer InVesallius(®) for rendering, Mesh Lab(®,) for positioning the models and CloudCompare for volumetric comparison, both observers matched cases with 100% accuracy and the level of coincidence in a identification situation. The uniqueness of the frontal sinus topography is remarkable and through the described technique, can be used in forensic as an identification method whenever both the sinus structure and antemortem computer tomography is available.

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

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

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

Evaluation of mandibular condyles in children with unilateral posterior crossbite.

The relationship of mandibular condyle dimensions and its association with unilateral posterior crossbite (UPXB) has been suggested in the literature. The purpose of this prospective study was to evaluate mandibular condyles on the left and right sides and between crossed and non-crossed sides in the sagittal and coronal planes, using cone-beam computed tomography (CBCT). Twenty CBCT images of 40 temporo mandibular joints (TMJs) in individuals in mixed dentition phase, which included 9 males (mean 7.9 years) and 11 females (mean 8.2 years), with unilateral posterior crossbite without premature contacts and functional mandibular shifts and with transverse maxillary deficiency. The criteria for sample exclusion included the presence of painful symptoms, facial trauma history, systemic diseases such as juvenile rheumatoid arthritis, mouth opening limitation (< 40 mm), congenital or genetic anomalies, and skeletal asymmetries that may result in TMJ disorders. Dimensional measurements of the condyles between the right and left sides and crossed and non-crossed sides in sagittal and coronal view were made. There was no significant difference between the measurements of the crossed and non-crossed sides in both sagittal and coronal view. These findings suggest that the presence of unilateral posterior crossbite in children with UPXB did not result in changes between the mandibular condyles in the right and left sides or between the crossed and non-crossed sides in the coronal or sagittal plane.

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

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

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