Annals of Anatomy-Anatomischer Anzeiger最新文献

Background

The teaching of anatomy from early days of medical education relied on the use of cadaver; hence, the present study assessed the support for whole-body donation among academic staff.

Methods

This is a cross-sectional study conducted from January to March 2024 in Southwestern Ugandan medical educational schools among 160 academic staff. Ethical approval was obtained and structured questionnaires were distributed to study participants in the selected Medical Educational Schools.

Results

Among the 160 sampled academic staff, only 16 % and 18 % supported the donation of their whole-body and the bodies of their relatives/friends for anatomical education respectively. The reason put forward for respondents support for whole-body donation were contribution to medical science (88.5 %) and learnt from someone’s body (53.8 %). The fear of misuse of their body (42.5 %), cultural (53.7 %) and religious (44.8 %) belief were the reasons for non-support for whole-body donation among the study participants.

Conclusion

This study concluded that support for whole-body donation among academic staff was low; reasons for non-support were fear of misuse of body, religious and cultural beliefs; hence, we recommend the need for massive desensitization of the public aimed at building confidence on whole-body donation in the community.

Background

The external auditory canal (EAC) exhibits a complex morphology and strong inter-individual variations. However, these have not yet been comprehensively described in the literature.

Purpose

This study aims to determine the width, height and cross-sectional area of the cartilaginous portion of the EAC and to describe the three-dimensional morphology and variability of different EACs.

Methods

Magnetic resonance imaging was performed on 870 subjects (401 male, 469 female, resulting in 1740 EACs) who participated in the longitudinal, population-based cohort study ‘Study of Health in Pomerania–START-3’. The height and width were measured in the cartilaginous part of the EAC, between the first and second bend. The variability of the EAC morphology was visualized in three-dimensional models.

Results

The mean height (vertical length) of the EAC was 8.62 mm (SD = 2.42) on the right, 8.47 mm (SD = 2.36) on the left. The width (horizontal length) was 4.08 mm (SD = 1.6) on the right, 3.93 mm (SD = 1.64) on the left. The EAC cross-section was 28.6 mm² (SD = 15.19) on the right, 27.15 mm² (SD = 14.33) on the left. The average cross-sectional area of the EAC in men was higher than in women. Subjects with larger body size had larger cross-sectional areas. Subjects with higher body mass index tended to have smaller cross-sections. Although the average EAC had an oval shape, a three-dimensional comparison of different EACs revealed strong individual variation in morphology.

Conclusion

This study enhances the understanding of otolaryngologists and anatomists regarding the complex morphology and variability of the cartilaginous portion of the EAC.

Background

The aim of this study was to determine the effect of root canal filling using different obturation materials combined with apicoectomy in upper central incisors under loading with 1 N and 100 N. The effect of incomplete root formation was also investigated.

Methods

Based on a CBCT-scan, a model of an upper central incisor was created. The model was altered to simulate different clinical situations: root canal treatment, apicoectomy at two different lengths and with different obturation protocols, and immature root formation after trauma. In each model the tooth was loaded with 1 and 100 N, and peak Von Mises stress of bone and tooth, elastic strain of the periodontal ligament, as well as rotation and displacement of the tooth were measured.

Results

Periapical surgery increases stress in dentin and the surrounding bone. Different obturation materials only produce minor differences in a coronally intact tooth.

Conclusions

Interincisal angle or loading direction strongly affects all measured values and needs to be considered when planning periapical surgery or comparing finite element analysis. Immature roots show the highest stress values in this study, reaching half the yield strength of dentine.

Background

The ossification centers in rabbit limbs are related to fetal age and bone maturation. Objective: To address the limited studies on ossification in the hind limbs of New Zealand rabbits, we investigated the prenatal and postnatal development of the pelvic and femur bones.

Methods

Double staining with Alcian Blue and Alizarin Red, computed tomography (CT), and 3D reconstruction were employed to visualize and analyze ossification centers in detail.

Results

Using double staining, we observed these patterns: At prenatal days 18 and 21, ossification centers appeared in the ilium. By prenatal days 23 and 25, ossification began in the ischium. On postnatal day 1, ilium ossification centers spread across most of the ilium wings, except for the iliac crest, and new centers appeared in the pubis and cotyloid bones. Most bones had ossified by the third week and one month postnatal, except for the iliac crest and ischial tuberosity. At 1.5 months, both were fully ossified. On day 18 post coitum, an ossification center was visible in the middle of the femur shaft. By day 28 post coitum, ossification extended through the shaft, and postnatally, new ossification spots appeared at the extremities by day one and week one. By the third week, complete ossification of the femur head, lesser trochanter, third trochanter, medial condyle, and lateral condyle was observed. At 1.5 months, the entire proximal extremity was ossified.

Conclusion

3D CT provided clear imaging of ossification progression in the pelvic and femur bones. This study enhances our understanding of vertebrate skeletal development.

To learn and comprehend the large amount of information in gross anatomy, undergraduate students must self-regulate their learning to be properly prepared for the exams within the available time. Even though there are many studies on learning strategies and their influence on test results and motivation, the aim of this study is to investigate characteristics of learning strategies in detail and in relation to the anatomy course of first semester students and how their use is related to anatomy test performance. For assessing the learning strategies, we used the short version of the questionnaire “Learning Strategies of University Students” (LIST-K) (Klingsieck, 2018). Further, we investigated potential influences of motivation and resources used during the self-regulated learning process. The participants in this study (N = 108) filled in the above-mentioned questionnaire LIST-K and a written multiple-choice anatomy test. A k-means cluster analysis revealed three groups of students differing in their self-reported use of learning strategies. Students used either (1) predominantly metacognitive and resource-related strategies, (2) predominantly cognitive strategies, or (3) no specific learning strategies at all. We found no significant overall relationships between the use of learning strategies and test performance. A stepwise linear regression identified the use of cognitive learning strategies (β =.269) as a significant predictor for test performance (R² =.149, p =.003), possibly as these specific learning strategies help with a systematic and effective approach while studying anatomy and retrieving large amount of memorized information. Further, motivation was identified as a negative predictor (β = −.277), which might be a result of the short time periods students have to study for exams. Overall findings underline the importance of self-regulated learning as a positive predictor for academic performance. By understanding these factors, a more student-centered approach could be adopted by educators to improve medical education and equip students with valuable approaches for their continuous education, even beyond university.

Background

The present study aims to investigate the feasibility of labeling ligaments using ultrasound-guided injections. On formalin-fixed cadavers, the anterolateral ligament was selected and targeted for demonstration. The development of portable ultrasound machines and the ability to connect them to tablets via Bluetooth or WLAN makes it an accessible tool to implement into the anatomical dissection courses in order to associate medical imaging (MRI and ultrasound), anatomical structures and their subsequent dissection.

Methods

8 formalin fixed human cadavers were used for the ultrasound-guided injections of 1 mL of blue latex into the anterolateral ligament. 8 cadavers were not injected with latex for comparative purposes. The injections were performed by an experienced ultra-sonographer. After approximately 10 months, five dissections were carried out by students during the dissection course and three specimens were dissected by anatomists.

Results

The anterolateral ligament was successfully marked and demonstrated in 7 out of 8 cases. In 4 out of 5 cases, the dissection was primarily conducted by students, while in 3 out of 3 cases, it was performed by anatomists. The accuracy was 80 % and 100 %, respectively.

Conclusion

The present study demonstrated that labeling obscure ligaments, such as the anterolateral ligament, using ultrasound guidance is feasible on formalin-fixed cadavers. It also showed that students can successfully perform the dissections as the structure is highlighted and that the time between injection and dissection (approximately 10 months) has little impact on the outcome. The use of ultrasound in dissection courses should be further encouraged.

Introduction and aim

Vitamin D supplementation in aging subjects manifests a positive effect on various health-related parameters. We performed a functionally-histological analysis of the adrenal cortex regarding the factors of vitamin D activity and corticosterone output after vitamin D3 application in a rat model of the andropause.

Material and methods

Middle-aged Wistar rats were divided into sham operated (SO; n=8), orchidectomized (Orx; n=8) and vitamin D3-treated orchidectomized (Orx+vit. D; n=8) groups. Vitamin D3 (5 μg/kg b.m.) was administered subcutaneously for three weeks, while the SO and Orx groups received the vehicle alone. Set objectives were achieved using histochemistry/immunohistochemistry, stereology, ultrastructural and biochemical analyses.

Results

Orchidectomy (Orx) decreased the adrenal cortex-related volume densities of vascular (p<0,0001), vitamin D receptor (VDR; p<0,0166), cytochrome P450 oxidase 2R1 (CYP 2R1; p<0,0001) and cytochrome P450 oxidase 24 (CYP 24; p<0,0001) depots, but increased the volume density of cytochrome P450 27B1 (CYP 27B1; p<0,0001) depots. In Orx+vit. D rats, increase of the adrenal cortex-related volume densities of collagen (p<0,0001), VDR (p<0,0001) and CYP 2R1 (p<0,0001) depots as well as the lipid-droplet diameter (p<0,0001) in adrenocortical outer zona fasciculata cells was observed, while a decrease of volume densities of the vascular (p<0,0001), CYP 27B1 (p<0,0001) and CYP 24 (p<0,0001) depots was registered, all versus Orx group. Plasma level of ACTH was decreased (p=0,0155) and serum concentrations of 25-hydroxyvitamin D3 and corticosterone were increased (p<0,0001 and p=0,0187, respectively), all after the same treatment.

Conclusions

Increased corticosterone output after vitamin D3 application to andropausal rats appears not to be related to increased availability of 25-hydroxyvitamin D3 and decreased degradation of 1,25-dihydroxyvitamin D3 in adrenal tissue, but rather involves the central regulatory mechanisms.

Background

To prevent the absorption and collapse of the labial bone plate of the anterior teeth, immediate implantation and socket shield technique have been increasingly applied to anterior dental aesthetic implant restoration.

Objective

To provide a biomechanical basis for implant restoration of maxillary anterior teeth, finite element analysis was used to investigate the stress peak and distribution in different anatomical sites of natural teeth, conventional immediate implantation and socket shield technique.

Methods

Three maxillary finite element models were established, including a maxillary incisor as a natural tooth, a conventional immediate implantation and a socket shield technique. A mechanical load of 100 N was applied to simulate and analyze the biomechanical behavior of the root, periodontal ligament (PDL), implant and surrounding bone interface.

Results

The stress distribution of the natural tooth was relatively uniform under load. The maximum von Mises stress of the root, periodontal ligament, cortical bone and cancellous bone were 20.14 MPa, 2.473 MPa, 19.48 MPa and 5.068 MPa, respectively. When the conventional immediate implantation was loaded, the stress was mainly concentrated around the neck of implant. Maximum stress on the surface of the implant was 102 MPa, the cortical bone was 16.13 MPa, and the cancellous bone was 18.29 MPa. When the implantation with socket shield technique was loaded, the stress distribution of the implant was similar to that of immediate implantation. Maximum stress on the surface of the implant was 100.5 MPa, the cortical bone was 23.11 MPa, the cancellous bone was 21.66 MPa, the remaining tooth fragment was 29.42 MPa and the periodontal ligament of the tooth fragment was 1.131 MPa.

Conclusions

1. Under static loading, both socket shield technology and conventional immediate implantation can support the esthetic restoration of anterior teeth biomechanically. 2.Under short-term follow-up, both immediate implant and socket shield technology achieved satisfactory clinical results, including bone healing and patient satisfaction. 3.The stress distribution is mainly located on the buccal bone surface of the implant and is associated with resorption of the buccal bone plate after implant replacement in both socket shield technology and conventional immediate implantation. 4.The presence of retained root fragment had an impact on the bone graft gap. In immediate implantation, the peak stress was located in the cortical bone near the implant position, while in socket shield technology, the peak stress was at the neck of the cortical bone corresponding to the retained root fragment.