Assessment of the maxilla-mandible-nasion angle in normal and aneuploid foetuses in the first trimester of pregnancy.

PURPOSE: This retrospective study aims to determine whether the maxilla-mandible-nasion (MMN) angle can be reliably measured in the first trimester, to describe normal ranges, and to determine if significant changes occur in foetuses with aneuploidies. METHODS: The MMN angle was measured in stored 2D-ultrasound images of 200 normal fetal profiles between 11+0 and 13+6 weeks of gestation. Each image was analyzed by two observers at two independent time points. Bland-Altmann analysis was performed to evaluate the reliability of the measurements. Additionally, the MMN angle was measured on sonograms from 140 aneuploid foetuses. RESULTS: The mean MMN angle in normal foetuses from 11 to 14 weeks of gestation was 15.4°. Reliability of the measurement was high when repeatedly measured by the same observer (ICC = 0.92 and 0.82) and between two observers (ICC = 0.77 and 0.63). Average MMN values in foetuses with trisomy 21, 13, and Turner syndrome were significantly higher than those measured in normal foetuses. The highest differences were observed in foetuses with trisomy 13. Among those, 62% had an MMN angle above the 95th percentile and 92% above the normal mean. CONCLUSION: The MMN angle can be reliably measured in early pregnancy and is abnormal in about 60% of foetuses with trisomy 13.

Surface Electromyography as a Method for Diagnosing Muscle Function in Patients with Congenital Maxillofacial Abnormalities.

Electromyography (EMG) is the most objective and reliable method available for imaging muscle function and efficiency, which is done by identifying their electrical potentials. In global surface electromyography (sEMG), surface electrodes are located on the surface of the skin, and it detects superimposed motor unit action potentials from many muscle fibers. sEMG is widely used in orthodontics and maxillofacial orthopaedics to diagnose and treat temporomandibular disorders (TMD) in patients, assess stomatognathic system dysfunctions in patients with malocclusions, and monitor orthodontic therapies. Information regarding muscle sEMG activity in subjects with congenital maxillofacial abnormalities is limited. For this reason, the aim of this review is to discuss the usefulness of surface electromyography as a method for diagnosing muscle function in patients with congenital malformations of the maxillofacial region. Original papers on this subject, published in English between 1995 until 2020, are located in the MEDLINE/PubMed database.

Tissue-engineered Maxillofacial Skeletal Defect Reconstruction by 3D Printed Beta-tricalcium phosphate Scaffold Tethered with Growth Factors and Fibrin Glue Implanted Autologous Bone Marrow-Derived Mesenchymal Stem Cells.

The study aimed to investigate whether a 3D printed beta-tricalcium phosphate (ß-TCP) scaffold tethered with growth factors and fibrin glue implanted autologous bone marrow-derived mesenchymal stem cells would provide a 3D platform for bone regeneration resulting in new bone formation with plasticity. Twenty 3D printed ß-TCP scaffolds, ten scaffolds engrained with osteogenic mesenchymal stem cells with fibrin glue (group A), and ten scaffolds used as a control group with ß-TCP scaffold and fibrin glue inoculation only (group B) were included in the study. Cell infiltration, migration, and proliferation of human osteogenic stem cells on the scaffolds were executed under both static and dynamic culture conditions. Each scaffold was examined post culture after repeated changes in the nutrient medium at 2, 4 or 8 weeks and assessed for opacity and formation of any bone-like tissues macroscopic, radiographic, and microscopic evaluation. Significant changes in all the prerequisite parameters compiled with an evaluated difference of significance showing maxillofacial skeletal repair via tissue engineering by ß-TCP scaffold and MSCs remains will be the most promising alternative to autologous bone grafts and numerous modalities involving a variety of stem cells, growth factors from platelet-rich fibrin.

Context-guided fully convolutional networks for joint craniomaxillofacial bone segmentation and landmark digitization.

Cone-beam computed tomography (CBCT) scans are commonly used in diagnosing and planning surgical or orthodontic treatment to correct craniomaxillofacial (CMF) deformities. Based on CBCT images, it is clinically essential to generate an accurate 3D model of CMF structures (e.g., midface, and mandible) and digitize anatomical landmarks. This process often involves two tasks, i.e., bone segmentation and anatomical landmark digitization. Because landmarks usually lie on the boundaries of segmented bone regions, the tasks of bone segmentation and landmark digitization could be highly associated. Also, the spatial context information (e.g., displacements from voxels to landmarks) in CBCT images is intuitively important for accurately indicating the spatial association between voxels and landmarks. However, most of the existing studies simply treat bone segmentation and landmark digitization as two standalone tasks without considering their inherent relationship, and rarely take advantage of the spatial context information contained in CBCT images. To address these issues, we propose a Joint bone Segmentation and landmark Digitization (JSD) framework via context-guided fully convolutional networks (FCNs). Specifically, we first utilize displacement maps to model the spatial context information in CBCT images, where each element in the displacement map denotes the displacement from a voxel to a particular landmark. An FCN is learned to construct the mapping from the input image to its corresponding displacement maps. Using the learned displacement maps as guidance, we further develop a multi-task FCN model to perform bone segmentation and landmark digitization jointly. We validate the proposed JSD method on 107 subjects, and the experimental results demonstrate that our method is superior to the state-of-the-art approaches in both tasks of bone segmentation and landmark digitization.

Whole-exome sequencing identified compound heterozygous variants in ROR2 gene in a fetus with Robinow syndrome.

BACKGROUND: Autosomal recessive Robinow syndrome (ARRS) is a rare genetic disorder, which affects the development of multiple systems, particularly the bones. OBJECTIVES: The aim of this study was to investigate the genetic cause of a ARRS fetus and to evaluate the reliability of whole-exome sequencing (WES) in prenatal diagnosis on cases with indistinguishable multiple malformation. METHODS: Clinical and ultrasonic evaluations were conducted on the fetus, and multiplatform genetic techniques were used to identify the variation responsible for RS. The pathogenicity of the novel variation was evaluated by in silico methods. Western blotting (WB) and immunohistochemistry (IHC) were performed on fetal tissues after the fetus' stillbirth and postabortal autopsy. RESULTS: A compound heterozygous variation consisting c.613C > T and c.904C > T in ROR2 gene was identified. In silico prediction suggested that c.904C > T was a deleterious variant. IHC result demonstrated that ror2 expression level of the proband in osteochondral tissue significantly increased comparing with that of the control sample. CONCLUSIONS: For the first time in Chinese population, we characterized a novel variation in ROR2 gene causing ARRS. This study extended the mutation spectrum of ARRS and provided a promising strategy for prenatal diagnosis of cases with ambiguous multiple deformities.

A New Software Suite in Orthognathic Surgery : Patient Specific Modeling, Simulation and Navigation.

Orthognathic surgery belongs to the scope of maxillofacial surgery. It treats dentofacial deformities consisting in discrepancy between the facial bones (upper and lower jaws). Such impairment affects chewing, talking, and breathing and can ultimately result in the loss of teeth. Orthognathic surgery restores facial harmony and dental occlusion through bone cutting, repositioning, and fixation. However, in routine practice, we face the limitations of conventional tools and the lack of intraoperative assistance. These limitations occur at every step of the surgical workflow: preoperative planning, simulation, and intraoperative navigation. The aim of this research was to provide novel tools to improve simulation and navigation. We first developed a semiautomated segmentation pipeline allowing accurate and time-efficient patient-specific 3D modeling from computed tomography scans mandatory to achieve surgical planning. This step allowed an improvement of processing time by a factor of 6 compared with interactive segmentation, with a 1.5-mm distance error. Next, we developed a software to simulate the postoperative outcome on facial soft tissues. Volume meshes were processed from segmented DICOM images, and the Bullet open source mechanical engine was used together with a mass-spring model to reach a postoperative simulation accuracy <1 mm. Our toolset was completed by the development of a real-time navigation system using minimally invasive electromagnetic sensors. This navigation system featured a novel user-friendly interface based on augmented virtuality that improved surgical accuracy and operative time especially for trainee surgeons, therefore demonstrating its educational benefits. The resulting software suite could enhance operative accuracy and surgeon education for improved patient care.

Comparative Study of Mandible Ramus Morphology Using 3-dimensional CT in Sagittal Split Ramus Osteotomy.

The purpose of the present study was to investigate the relevance of the external morphology of the mandibular ramus, internal bone tissue structure, and maxillofacial morphology at the site for sagittal split ramus osteotomy among different facial skeletal patterns. A total of 80 patients with jaw deformities who underwent sagittal split ramus osteotomy were included in the study. The patients were divided into two groups based on facial skeletal type (skeletal Class II or skeletal Class III). A further 7 patients with no skeletal abnormalities were established as the control group (skeletal Class I). Computed tomography images obtained from these patients were 3-dimensionally reconstructed and the morphology of the mandibular ramus determined. Thickness at the mandibular foramen in Class II was greater than that in Class III, and showed the lowest value at the midpoint of the mandibular foramen and mandibular notch in Class I. Mandibular morphology showed change according to facial skeletal type. Correlations were also observed between the cephalometric analysis values and mandibular morphology.

Feasibility and Accuracy of Noncontact Three-Dimensional Digitizers for Geometric Facial Defects: An In Vitro Comparison.

PURPOSE: To evaluate the feasibility and accuracy of noncontact three-dimensional (3D) digitization systems for capturing facial defects. MATERIALS AND METHODS: A stone model of a facial defect was digitized using high-accuracy industrial computed tomography as a reference scan. The model was also scanned using four different types of noncontact 3D digitizers: a laser beam light-sectioning technology with camera system and three different stereophotogrammetry systems. All 3D images were reconstructed with corresponding software and saved as standard triangulated language (STL) files. The 3D datasets were geometrically evaluated and compared to the reference data using 3D evaluation software. Kruskal-Wallis H tests were performed to assess differences in absolute 3D deviations between scans, with statistical significance defined as P < .05. RESULTS: The four noncontact 3D digitization systems were feasible for digitizing the facial defect model, although the median 3D deviation of the four digitizers varied. There was a significant difference in accuracy among the digitizers (P < .001). CONCLUSION: Digitization of facial defect models using various noncontact 3D digitizers appears to be feasible and is most accurate with laser beam light-sectioning technology. Further investigations assessing digitization of facial defects among patients are required to clinically verify the results of this study.

Multidetector Row Computed Tomography in Maxillofacial Imaging.

Multidetector row CT (MDCT) offers superior soft tissue characterization and is useful for diagnosis of odontogenic and nonodontogenic cysts and tumors, fibro-osseous lesions, inflammatory, malignancy, metastatic lesions, developmental abnormalities, and maxillofacial trauma. The rapid advances in MDCT technology, including perfusion CT, dual-energy CT, and texture analysis, will be an integrated anatomic and functional high-resolution scan, which will help in diagnosis of maxillofacial lesions and overall patient care.

The role of 3D printing in treating craniomaxillofacial congenital anomalies.

Craniomaxillofacial congenital anomalies comprise approximately one third of all congenital birth defects and include deformities such as alveolar clefts, craniosynostosis, and microtia. Current surgical treatments commonly require the use of autogenous graft material which are difficult to shape, limited in supply, associated with donor site morbidity and cannot grow with a maturing skeleton. Our group has demonstrated that 3D printed bio-ceramic scaffolds can generate vascularized bone within large, critical-sized defects (defects too large to heal spontaneously) of the craniomaxillofacial skeleton. Furthermore, these scaffolds are also able to function as a delivery vehicle for a new osteogenic agent with a well-established safety profile. The same 3D printers and imaging software platforms have been leveraged by our team to create sterilizable patient-specific intraoperative models for craniofacial reconstruction. For microtia repair, the current standard of care surgical guide is a two-dimensional drawing taken from the contralateral ear. Our laboratory has used 3D printers and open source software platforms to design personalized microtia surgical models. In this review, we report on the advancements in tissue engineering principles, digital imaging software platforms and 3D printing that have culminated in the application of this technology to repair large bone defects in skeletally immature transitional models and provide in-house manufactured, sterilizable patient-specific models for craniofacial reconstruction.

A Simple Scatter Reduction Method in Cone-Beam Computed Tomography for Dental and Maxillofacial Applications Based on Monte Carlo Simulation.

The quality of images obtained from cone-beam computed tomography (CBCT) is important in diagnosis and treatment planning for dental and maxillofacial applications. However, X-ray scattering inside a human head is one of the main factors that cause a drop in image quality, especially in the CBCT system with a wide-angle cone-beam X-ray source and a large area detector. In this study, the X-ray scattering distribution within a standard head phantom was estimated using the Monte Carlo method based on Geant4. Due to small variation of low-frequency scattering signals, the scattering signals from the head phantom can be represented as the simple predetermined scattering signals from a patient's head and subtracted the projection data for scatter reduction. The results showed higher contrast and less cupping artifacts on the reconstructed images of the head phantom and real patients. Furthermore, the same simulated scattering signals can also be applied to process with higher-resolution projection data.

Joint Craniomaxillofacial Bone Segmentation and Landmark Digitization by Context-Guided Fully Convolutional Networks.

Generating accurate 3D models from cone-beam computed tomography (CBCT) images is an important step in developing treatment plans for patients with craniomaxillofacial (CMF) deformities. This process often involves bone segmentation and landmark digitization. Since anatomical landmarks generally lie on the boundaries of segmented bone regions, the tasks of bone segmentation and landmark digitization could be highly correlated. However, most existing methods simply treat them as two standalone tasks, without considering their inherent association. In addition, these methods usually ignore the spatial context information (i.e., displacements from voxels to landmarks) in CBCT images. To this end, we propose a context-guided fully convolutional network (FCN) for joint bone segmentation and landmark digitization. Specifically, we first train an FCN to learn the displacement maps to capture the spatial context information in CBCT images. Using the learned displacement maps as guidance information, we further develop a multi-task FCN to jointly perform bone segmentation and landmark digitization. Our method has been evaluated on 107 subjects from two centers, and the experimental results show that our method is superior to the state-of-the-art methods in both bone segmentation and landmark digitization.

Management of a large diffuse maxillofacial arteriovenous malformation previously treated with ligation of ipsilateral arterial supply.

A 32 year-old male presented with a pulsatile facial mass with palpable thrill and audible bruit. Imaging revealed a very large diffuse left-sided facial arteriovenous malformation with extensive bilateral supply, as well as a previously ligated left external carotid artery. Endovascular treatment was required to control associated hemorrhagic events as well as for palliation and was delivered via the contralateral and ipsilateral collateral supply because of ligation of the direct route to the nidus. In addition, the patient received intravenous bevacizumab and intraarterial bleomycin therapy. Under such circumstances, endovascular embolization remains often the only option when emergent therapy for massive haemorrhage is required. Collaboration and treatment planning with head and neck surgery is imperative and should be performed from the onset, avoiding disastrous ligation of arterial feeders.

Indications for cone beam computed tomography in children and young patients in a Turkish subpopulation.

BACKGROUND: Cone beam computed tomography (CBCT) imaging is widely used in children; however, it remains controversial because of the health effects of radiation. AIM: This retrospective study investigated the indications for CBCT and dentomaxillofacial pathologies in paediatric patients. MATERIALS AND METHODS: CBCT images of 329 paediatric patients (i.e., aged <18 years) were investigated retrospectively. CBCT images were obtained with five fields of view (FOV). CBCT indications were categorised as surgery and orthodontics. The effects of age, sex, and FOV were evaluated. The level of significance was P = 0.05. RESULTS: The most common orthodontic indications were malocclusion and dentomaxillofacial anomalies (38.5%), followed by the localisation of impacted teeth (33.1%). There was no relationship between sex and indications. There were significant associations between age groups and malocclusion and dentomaxillofacial anomalies, localisation of impacted teeth, and trauma. The face was the most frequently imaged region, followed by the jaws (maxilla and mandible). CONCLUSION: The most common indication for CBCT was malocclusion and dentomaxillofacial anomalies in the primary and permanent dentition age groups, whereas the localisation of impacted teeth was the most common indication in the mixed dentition age group. Generally, CBCT was indicated in orthodontics and surgery.

Cirurgia ortognática: assimetria facial e a limitação do planejamento manual com articulador semi-ajustável Acon (ASA) - correção com planejamento virtual (3D) / Orthognathic surgery: facial asymmetry and the limitation of manual planning with the semi-adjustable Arcon (ASA) articulator ­ correction with virtual (3D) planning

Introdução: os casos de assimetria facial são considerados os de maior complexidade dentro do âmbito da cirurgia Buco-Maxilo-Facial, devido a alteração esquelético-morfológica nos três planos do espaço (Pitch, Yaw e Roll). Estes planos foram trazidos do posicionamento de uma aeronave no espaço para o mundo da cirurgia, mais especificamente ao planejamento virtual, para romper as limitações do planejamento manual e a plataforma de Erickson, usados durante décadas para correção não só de casos simples envolvendo movimentos puros dos ossos, como também assimetrias. Hoje é sabido que o planejamento manual ainda é usado, porém, vem caindo em desuso devido as suas limitações. A cirurgia virtual vem ganhando muito espaço e se superando a cada dia. Objetivo: relatar um caso de cirurgia ortognática em que a paciente era portadora de assimetria facial, planejada de forma manual (tradicional) e os erros encontrados após 04 anos, levando a uma re-operação baseada em planejamento virtual.

Introduction: the cases of facial asymmetry are considered the most complex within the scope of oral and maxillofacial surgery due to skeletal-morphological changes in the three planes of space (Pitch, Yaw and Roll). These plans were brought from the position of an aircraft in space to the world of surgery, specifically the virtual planning to break the limitations of manual planning and Erickson platform, used for decades to fix not only simple cases involving purê bone's movements as well as asymmetries. Today it is known that manual planning is still used, however, it has fallen into disuse because of its limitations. Virtual surgery is gaining a lot of space and surpassing every day. Objective: this article aims to report a case of orthognathic surgery in which the patient had facial asymmetry, planned manually (traditional) and the errors found after 04 years, leading to a virtual planning-based re-operation.

Prenatal diagnosis of Binder's syndrome: report of two cases.

OBJECTIVE: Binder syndrome is a rare congenital malformation presenting an abnormal maxilla's development associated to other characteristical facial features, like absence or decreased nasal bridge, short nasal columella, convex upper lip with associated dental Angle Class III malocclusion, atrophy of the nasal mucosa, and absence of the frontal sinus. Mental retardation and other clinical signs may also be present. Two cases of Binder syndrome were diagnosed at 22 weeks of gestation during the second trimester ultrasound (2D). CASES REPORT: The first feature detected, in both cases, was a flattened fetal nose in the mid-sagittal plane. Further controls objectivated absence of the naso-frontal angle and a mild hypertelorism. In both cases the parents were informed of the findings and the impossibility of excluding other associated features diagnosed after birth. Once the differential diagnosis was performed, one of the couples decided to terminate the pregnancy. The findings postmortem confirmed the diagnosis. In the second case, the newborn presented the phenotype previously detected, however, a normal psychomotor development was eventually evidenced. CONCLUSION: The Binder syndrome is an uncommon clinical entity with a recognizable congenital condition characterized by a retruded midface and an extremely flat nose. The exact birth prevalence remains unknown. It is important to understand that Binder's syndrome has a variable prognosis, depending on the other associated features it presents. When diagnosed, an accurate differential diagnosis has to be performed.