Introduction: Few interspecies comparisons of alveolar bone have been documented, and this knowledge gap raises questions about which animal models most accurately represent human dental conditions or responses to surgical interventions. Objectives: The objective of this study was to employ state-of-the-art quantitative metrics to directly assess and compare the structural and functional characteristics of alveolar bone among humans, mini pigs, rats, and mice. Methods: The same anatomic location (i.e., the posterior maxillae) was analyzed in all species via micro–computed tomographic imaging, followed by quantitative analyses, coupled with histology and immunohistochemistry. Bone remodeling was evaluated with alkaline phosphatase activity and tartrate-resistant acid phosphatase staining to identify osteoblast and osteoclast activities. In vivo fluorochrome labeling was used as a means to assess mineral apposition rates. Results: Collectively, these analyses demonstrated that bone volume differed among the species, while bone mineral density was equal. All species showed a similar density of alveolar osteocytes, with a highly conserved pattern of collagen organization. Collagen maturation was equal among mouse, rat, and mini pig. Bone remodeling was a shared feature among the species, with morphologically indistinguishable hemiosteonal appearances, osteocytic perilacunar remodeling, and similar mineral apposition rates in alveolar bone. Conclusions: Our analyses demonstrated equivalencies among the 4 species in a plurality of the biological features of alveolar bone. Despite contradictory results from older studies, we found no evidence for the superiority of pig models over rodent models in representing human bone biology. Knowledge Transfer Statement: Animal models are extensively used to evaluate bone tissue engineering strategies, yet there are few state-of-the-art studies that rigorously compare and quantify the factors influencing selection of a given animal model. Consequently, there is an urgent need to assess preclinical animal models for their predictive value to dental research. Our article addresses this knowledge gap and, in doing so, provides a foundation for more effective standardization among animal models commonly used in dentistry.

Objectives This study aims to evaluate the incidence of osteonecrosis (ONC), with a special focus on ONC of the femoral head (ONFH), in novel coronavirus disease 2019 (COVID-19) patients two years after the pandemic. Patients and methods This prospective study included COVID-19 patients who were admitted to our center between March 2020 and June 2020. A total of 472 patients (289 males, 183 females; mean age: 42.3±12.0 years; range, 18 to 60 years) were arranged in a list according to their date and time of admission and, then, divided into two groups: those not receiving corticosteroid (CS) treatment (Group 1, n=236) and those receiving CS treatment (Group 2, n=236). The patients were evaluated for joint pain based on X-rays and magnetic resonance imaging scans, and the patients were routinely followed. For each patient in Group 2, additional data regarding CS use were recorded. The possible relationship between ONC and risk factors was analyzed. Results Both groups were similar in terms of age and sex. Group 2 had a significantly longer hospitalization period. A significant increase in the number of painful joints was observed in Group 2. At two years, 5.1% of the patients in Group 1 complained of at least one painful joint compared to 11.9% of patients in Group 2. Eight patients from Group 2 developed ONC. Conclusion The incidence of ONC after CS therapy in COVID-19 patients is on the rise. At two years, 5% of patients receiving various doses of CSs may develop ONC. Residual joint pain is common even after recovering from the virus. No relationship is evident between the duration of treatment, cumulative dosage of medication, maximum one-day dosage received, and the presence of ONC.

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Several fractures that occur in the human body depend on trauma or as a result of hormonal and bone fatigue. Fracture types that take place out of the neck area of the femoral bone are named femoral shaft fractures. Femoral shaft fractures are frequent conditions in orthopedics. Conventional plating method is a method that necessitates the fixation of the contact surface by contacting the epiphyses used in the treatment of such fractures. This method is known to be efficent in speeding up the healing process by reducing the movement between the epiphyses. In this study, femur models which are plated in various forms with fractures were analyzed with computer-aided finite element software and stresses on bone surfaces and fracture surfaces were determined. It is aimed to determine the best result by examining the relationship between the inputs such as the number of screws used during plating, the fixation area and material selection and the outputs obtained by finding the stresses on the bone surface and stresses on the broken surfaces.

The human body is an intermediate host for Echinococcus granulosus (E. granulosus), which is the most common cause of hydatid disease. This type of parasite mostly affects the liver and lungs. Primary involvement of subcutaneous tissue is extremely rare. A 51-year-old female presented with the complaint of swelling on the upper medial right thigh. On ultrasonography, a cystic lesion with thick walls, approximately 50¥90 mm in size, was observed approximately 8.5 mm from the skin within the muscle planes in the medial section of the right thigh. Entry was made over the mass from the medial thigh and the mass was totally excised. The histopathological diagnosis was confirmed as hydatid cyst. No pathological findings consistent with hydatid cyst were determined in the liver or other systems. In particular, in areas of endemic hydatid disease, it must be kept in mind that these types of atypical localizations, other than in the liver and lungs, can be encountered in many different anatomic regions.