Computed tomography examination of the os cordis in a lamb (Ovis aries Linnaeus, 1758)

Objective. The present paper aims to investigate the role of computed tomography as an imaging technique of diagnosis in the identification of the os cordis in ovine, and also how this anatomical structure is morphotopographically characterized in macro and microscopic contexts, seeking to contribute for its functional understanding. Materials and method. The heart of a young male ovine had been donated to the Laboratory of Animal Anatomy of the Surgery Department of the FMVZ/USP, first being subject to a post-mortem examination by means of the cardiac “shedding” (transverse cross sectioning of the heart). A tomographic examination of the anatomic specimen was carried out, as well as the dissection and histological analysis of the collected sample. Results. The results indicate the presence of an osseous structure of 6.39 mm in length, located in the aortic valve of the heart, next to a ring comprised by three valve flaps, tendinous cords, and papillary muscles. The histological findings consist of fibrous connective tissue, cancellous bone tissue, and calcified hyaline cartilage wherein the cardiomyocytes are attached. Conclusions. It is concluded that computed tomography, even though seldom applied to animals of zootechnical interest, poses as an effective tool for the visualization of the os cordis in lambs.

Multi-parameter-based Radiological Diagnosis of Chiari Malformation using Machine Learning Technology

Background: The known primary radiological diagnosis of Chiari Malformation-I (CM-I) is based on the degree of tonsillar herniation ( TH) below the Foramen Magnum (FM). However, recent data also shows the association of such malformation with smaller posterior cranial fossa (PCF) volume and the anatomical issues regarding the Odontoid. This study presents the achieved result regarding some detected potential radiological findings that may aid CM-I diagnosis using several machine learning (ML) algorithms. Materials and Methods: Between 2011 and 2020, radiological examinations of 100 clinically/radiologically proved symptomatic CM-I cases and 100 control were evaluated by matching age and gender. A team of Neuroradiologists had reviewed the MR images of the study population. A total of 11 different radiological parameters were assessed for CM-I diagnosis. The parameters were defined and examined in 5 designed different ML algorithms. Statistical analysis was conducted for data analysis. Results: The mean age of patients was 29.92 ± 15.03 years. The primary presenting symptoms were headaches (62%). Syringomyelia and retrocurved-odontoid were detected in 34% and 8% of patients, respectively. All of the morphometric measures were significantly different between the groups, except for the distance from the dens axis to the posterior margin of FM. The Radom Forest model is found to have the best 1.0 (14 of 14) ratio of accuracy in regard to 14 different combinations of morphometric features. Conclusion: This study indicates the potential usefulness of ML-guided PCF measurements, other than TH, that may be used to predict and diagnose CM-I accurately. Our results support the view of TH as a single radiological parameter may fail during the diagnosis of CM-I. Combining two or three preferable osseous structure-based parameters may increase the accuracy of radiological diagnosis of CM-I.

Dynamic evolution of osseous structure in osteonecrosis of the femoral head and dynamic collapse risks: a preliminary CT image study

Background Collapse risk of osteonecrosis of the femoral head (ONFH) is estimated mainly based on static indicators, including lesion size and lesion location, but bone repairing is a dynamic process that lasts for years. The present study attempted to analyze the dynamic evolution of the osseous structure and its correlation with radiographic progression. Methods This retrospective study included 50 hips with ONFH from 50 patients. Participants were divided into the non-collapse group (n = 25) and the collapse group (n = 25). Original files of the initial computed tomography (CT) images were imported into imaging processing software for morphology analysis. The volume of sclerotic bone, the volume of soft tissue, and bone mineral density (BMD) were calculated. The linear correlations between the aforementioned indicators and the disease duration were estimated. The logistic regression analysis was conducted to evaluate the correlation of these indicators with the radiographic progression. Receiver operating characteristic (ROC) analysis was used to evaluate these indicators’ prediction performance. Results The volume of sclerotic bone and the BMD grew with disease duration, but the volume of soft tissue decrease. The logistic regression analysis found that the volume of sclerotic bone and the BMD were statistically associated with radiographic progression. The ROC analysis found that the regression model, which integrated the volume of sclerotic bone and the BMD, had satisfactory performance in predicting radiographic progression. Conclusion The present study suggested a dynamic evolution of the osseous structure and a dynamic variation trend of the collapse risk in ONFH. The volume of sclerotic bone and the BMD might serve as further prognostic indicators when estimating the collapse risk.

Evaluating the effects of functional orthodontic treatment on mandibular osseous structure using fractal dimension analysis of dental panoramic radiographs

ABSTRACT Objective To evaluate the effects of functional appliance treatment on mandibular trabecular structure using fractal dimension (FD) analysis of dental panoramic radiographs. Materials and Methods This study was conducted using digital panoramic radiographs of 45 patients with Class II malocclusion treated with functional appliances (treatment group, mean age: 11.39 ± 0.97 years; 23 girls, 22 boys) acquired before (T0) and after (T1) treatment and the panoramic radiographs of 45 control subjects who had undergone no orthodontic treatment (control group, mean age: 11.31 ± 0.87 years; 23 girls, 22 boys). FD values in the condylar process, mandibular corpus, and mandibular angle were analyzed from the panoramic radiographs of both groups. Results Analysis of changes in FD between T0 and T1 revealed significant increases in the FD values of the right and left condylar processes and right mandibular corpus in the treatment group (P < .001) and in the right condylar process in the control group (P < .05). Between-group comparisons demonstrated that the treatment group showed greater changes in the condylar process (right, P < .001; left, P < .05) and right mandibular corpus (P < .05) compared to controls. Correlation analysis between the cephalometric and FD changes in the treatment group showed the right condylar process changes were negatively correlated with GoGn/SN angle (P < .05) and positively correlated with Co-Go (P < .05), although these correlations were weak. Conclusions FD analysis demonstrated significant changes in trabeculation of the condyle and mandibular corpus in the treatment group compared to the control group. Functional appliance treatment may lead to skeletal correction by altering skeletal form and trabeculation of the mandibular bone.

Rotation of the maxillomandibular complex in orthognathic surgery; A Review

Introduction: In orthognathic surgery, maxillomandibular complex (MMC) refers to a three-dimensional dento-osseous structure consisting of the surgically-mobilized part of the maxilla together with the distal segment (i.e., tooth bearing segment) of the mandible (either surgically mobilized or not). In fact, MMC is the skeletal part of the lower face. The size, shape And position of MMC play a major role in soft tissue esthetics of the lower face. Materials and methods: A comprehensive review of the current data regarding effects of maxillomandibular complex rotation in sagittal plane, on “occlusal plane, TMJ, sleep apnea, paranasal soft tissues, upper lip, chin, cervicomental soft tissues” was conducted. Results: MMC rotation and translation could take place in any of the three planes of reference including sagittal, coronal, and horizontal. Any kind of changes in the position of MMC could have its own functional and esthetic consequences. In general, patients with convex facial profiles require counterclockwise rotation while patients with concave profiles require clockwise rotation. Conclusion: MMC not only has great impacts on facial esthetics, but also has significant functional effects, for example in breathing and mastication. Alteration in the position of MMC is possible by orthognathic surgery.

The Source and the Course of the Articular Branches to the T4-T8 Zygapophysial Joints

Objective To define the source and the course of the articular branches to the midthoracic zygapophysial (“z”) joints. Design Cadaveric dissection. Setting The Gross Anatomy Laboratory of the Duke University School of Medicine. Subjects Ten human cadaveric thoraces. Methods Gross and stereoscopic dissection of dorsal rami T4-T8 was performed bilaterally on 10 adult embalmed cadavers. The medial and lateral branches were traced to their origins from the dorsal rami, and the course of the articular nerves was documented through digital photography. Radio-opaque wire (20 gauge) was applied to the nerves. Fluoroscopic images were obtained to delineate their radiographic course with respect to osseous landmarks. Results Forty-eight inferior articular branches were identified. Three (6.3%) originated from the medial branch and 44 (91.7%) from the dorsal ramus. One was indeterminate. Fifty-one superior articular branches were identified. Eight (15.7%) originated from the medial branch and 43 (84.3%) from the dorsal ramus. In 12% of cases (6/50), there was side-to-side asymmetry in the origins of the articular branches. Nerves were commonly suspended in the intertransverse space. The articular branches contacted an osseous structure in only 39% of cases. As previously reported, a “descending branch” was not identified in any specimen. Conclusions Articular branches to the T4-T8 z-joints have substantial inter- and intraspecimen variability of origin. They typically arise from the dorsal ramus rather than the medial branch and frequently do not contact any osseous structure to allow percutaneous needle placement.

Screw-Hole Clusters in Acetabular Cups: A Morphological Study of Optimal Positioning of Screw-Holes

Background Rigid and safe transacetabular screw fixation in total hip arthroplasty (THA) is achieved by pursuing deeper bone stock and avoiding injuries to the neurovascular structures, but these efforts can be restricted by the distribution of screw-holes on cups by the manufacturer. We therefore tried to determine: (i) optimal screw-hole positions on cups to allow anatomical placement of screws; (ii) rationality of the basic 3-screw-hole cluster on commercial cups; and (iii) the optimum method for placing commercial cups in accordance with acetabular anatomy. Methods Periacetabular osseous structure of 64 hips and arterial structures of 50 hips were three-dimensionally reconstructed. Simulated transacetabular screw fixation during THA was performed in these hips with 3 different screw lengths (15, 25, and 35 mm) to define deeper and safer screw trajectories. Screw-hole locations of 7 commercially available cups were measured and matched with the periacetabular anatomy. Results When the cup was placed into the acetabulum at 45° of abduction and 20° of anteversion, the optimal locations of 2 screw-holes on the cups were at 30° and 64° of latitude, with a 35° separation angle. The inversetriangle distribution pattern was safer than the triangle pattern in basic 3-screw-hole-cluster cups. When placing the commercial cups, 5°-10° of anterior rotation can be added to allow better screw trajectories. Conclusions Our study determined optimal screw-hole positions and their distribution pattern on cups. We describe methods to place the commercial cups that are not designed according to acetabular anatomy.

Morphology, development and heterochrony of the carapace of Giant Amazon River Turtle Podocnemis expansa (Testudines, Podocnemidae)

With aim to report the ontogeny of the osseous elements of the carapace in Peurodiras, 62 embryos and 43 nestlings of Podocnemis expansa were collected and submitted to the clearing and staining technique of bones and cartilages and study of serial histological slices. The carapace has mixed osseous structure of endo and exoskeleton, formed by 8 pairs of costal bones associated with ribs, 7 neural bones associated with neural arches, 11 pairs of peripheral bones, 1 nuchal, 1 pygal and 1 suprapygal. This structure begins its formation in the beginning of stage 16 with the ossification of the periosteal collar of the ribs. With exception of the peripheral bones, the other ones begin their ossification during the embrionary period. In histologic investigation it was found that the costal bones and neural bones have a close relation to the endoskeleton components, originating themselves as intramembranous expansions of the periosteal collar of the ribs and neural arches, respectively. The condensation of the mesenchyme adjacent to the periosteal collar induces the formation of spikes that grow in trabeculae permeated by fibroblasts below the dermis. The nuchal bone also ossifies in an intramembranous way, but does not show direct relation to the endoskeleton. Such information confirms those related to the other Pleurodira, mainly with Podocnemis unifilis, sometimes with conspicuous variations in the chronology of the ossification events. The formation of dermal plates in the carapace of Pleurodira and Criptodira follow the same pattern.