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Exhibitions of plastinated specimens are popular around the world, but most people are not aware of the basics of plastination process because they are not interested in reading the related writings. Comics are an attractive medium and could solve this problem. The objective of this study was to enhance public comprehension of plastination using comics. Three topics were selected for the comics: the traditional ways to preserve dissected cadaver specimens, the plastination technique used to resolve the problems of the traditional ways, and the public display of the plastinated specimens. The 67 comic frames were drawn in simple style. The comics were available online (anatomy.co.kr) free of charge. The original files of the comics will be provided to those who utilize the files for making the signs or leaflets for exhibitions. The comics in this study, whether online or not, are expected to help people recognize the value of plastination; the comics' quantity and quality will be upgraded in a variety of ways. [ABSTRACT FROM AUTHOR]

Objective: The myodural bridge (MDB) connects the suboccipital musculature to the spinal dura mater (SDM) as it passes through the posterior atlanto-occipital and the atlanto-axial interspaces. It has recently been proposed that head movement may assist in powering the movement of cerebrospinal fluid (CSF) via muscular tension transmitted to the SDM via the MDB. Methods: The present study utilized dogs as the experimental model to explore the MDB's effects on the CSF pressure (CSFP) during stimulated contractions of the suboccipital muscles as well as during manipulated movements of the atlanto-occipital and atlanto-axial joints. Additionally biomechanical tensile strength tests were conducted. Results: The tensile strength of the collagenous fibers passing through the dorsal atlanto-occipital and atlanto-axial interspaces were 0.16±0.04 MPa and 0.82±0.57 MPa, respectively. Passive head movement, including lateral flexion, rotation, as well as flexion--extension, all significantly increased CSFP. Furthermore, the CSFP was significantly raised from 12.41± 4.58 to 13.45±5.16 mm Hg when the obliquus capitis inferior (OCI) muscles of the examined specimens were electrically stimulated. Head movements appeared to be an important factor affecting CSF pressure, with the MDB of the suboccipital muscles playing a key role in this process. Conclusion: The present study provides direct evidence to support the hypothesis that the MDB may be a previously unappreciated significant power source (pump) for CSF circulation. [ABSTRACT FROM AUTHOR]

To clarify the path of the temporal branch of facial nerve (TB) crossing the zygomatic arch (ZA). Eighteen fresh adult heads specimens were carefully dissected in the zygomatic region, with the location of TB as well as its number documented. The hierarchical relationship between the temporal branch and the soft tissue in this region was observed on 64 P45 plastinated slices. 1. TB crosses the ZA as type I (21.8 %), type II (50.0 %,), and type III (28.1 %) twigs. 2. At the level of the superior edge of the ZA, the average distance between the anterior trunk of TB and the anterior part of the auricle is 36.36±6.56 mm, for the posterior trunk is 25.59±5.29 mm. At the level of the inferior edge of the ZA, the average distance between the anterior trunk of TB and the anterior part of the auricle is 25.77±6.19 mm, for the posterior trunk is 19.16±4.71 mm. 3. The average length of ZA is 62.06±5.36 mm. TB crosses the inferior edge of the ZA at an average of 14.67±6.45 mm. TB crosses the superior edge of the ZA at an average of 9.08±4.54 mm. 4. At the level of the ZA, TB passes on the surface of the pericranium while below the SMAS. The TB obliquely crosses the middle 1/3 part of the superior margin of the ZA and the junction of the middle 1/3 part and the posterior 1/3 part of the inferior margin of the ZA below the SMAS while beyond the periosteum. It is suggested that this area should be avoided in clinical operation to avoid the injury of TB. [ABSTRACT FROM AUTHOR]

At present, the anatomical relationship the mid-portion of popliteus tendon complex (PTC) and the surrounding tissues is still unclear, especially its relationship to the posterior cruciate ligament (PCL). It affected the anatomical reconstruction of the posterolateral complex (PLC) injury. A total of 30 cases of the adult human knee joint fixed with formalin were used. Sagittal sections were made in 14 knee joints by the P45 plastination technique and dissection of 16 cases of knee joints. The P45 section revealed that the popliteus muscle fascia ran superiorly over the posterior edge of the tibial intercondylar eminence, and turned forward to be integrated into the PCL. Laterally, near the posterior edge of the lateral tibial plateau, the popliteus tendon penetrates through the articular capsule (AC), where two dense fibrous bundles were given off upwards by the popliteus tendon: one was the ventral fiber bundle, which ran superiorly over the posterior edge of the tibial plateau and then moved forwards to connect with the lateral meniscus; the dorsal fibers bundle ascended directly and participated in the AC. Meanwhile, the popliteus muscle dissection showed that at the posterior edge of the platform of the lateral condyle of the tibia, at the tendon-muscle transition, the PTC and AC were anchored to PCL. [ABSTRACT FROM AUTHOR]

The corporo-glans ligament is the ligament connecting the corpus cavernosum and the glans of the penis. The anatomical description of the corporo-glans ligaments shape is still uncertain, this knowledge affects penile reconstructive procedures. The anatomy of the corporo-glans ligament was analyzed and recorded via observing sagittal sections of 10 different penile P45 plastination sections. According to the P45 plastination sections, the corporo-glans junction displayed a fibrous tissue band connecting the distal ends of the two corpus cavernous (CC) with the glans penis (GP). The fibrous band was a round-obtuse shape and ran deep into the glans of the penis and occupied about 2/3 of the whole GP. The original end was laid in a socket embedded in the GP. The density of the fibers of the ligament at the original end close to the tunica albuginea was less than that of the other parts. The fibers originating from the tunica albuginea, directly extended to the blind end of the two CC, covering the distal end of the two CC. [ABSTRACT FROM AUTHOR]

The myodural bridge is a dense connective tissue connecting muscles and ligaments to the spinal dura mater in the atlanto-occipital interspace. Some researchers believe that the myodural bridge may play a vital physiological role. It is possible, for instance, that the prevention of spinal dura mater infoldings might be involved in regulated cerebrospinal fluid circulation. For instance, it is possible to prevent spinal dura mater infoldings, regulating cerebrospinal circulation. Bats are nocturnal and the only mammals that can perform a genuine and sustained flight, whereas tree shrews are arboreal mammals that often climb to a high altitude of about 10,000 feet. Both animals have lifestyles that are different from other previously studied mammals. The study of these two animals will shed further light on the existence of the myodural bridge in mammals. Gross anatomical dissection was used to observe the connections between the deep muscles of the neck and the dura mater at the level of the atlanto-occipital interspace. The existing structures were analyzed using conventional and special histological staining techniques. The suboccipital regions in bats and tree shrews contained the rectus capitis dorsal major (RCDma), rectus capitis dorsal minor (RCDmi), oblique capitis anterior (OCA), and oblique capitis posterior (OCP). Dense connective tissue connects the RCDmi to the posterior atlanto-occipital membrane (PAOM) and the latter to the spinal dura mater. The myodural bridge in these mammals shares a similar structure to the myodural bridge in humans. Histological analyses confirmed that the connective fibers of the myodural bridge were primarily type I collagen fibers. In this study, it is supplemented by the existence of the myodural bridge in mammals. This further demonstrates that myodural bridge widely exists in the normal anatomy of mammals. This provides morphological support for a comparative anatomical study of the physiological function of the myodural bridge. [ABSTRACT FROM AUTHOR]

To establish an unprovable diagnostic indicative index reference for ultrasound examination of the fetal cerebral ventricles, based on the morphological characteristics throughout fetal nervous system development. Key ultrasonic morphological indicators of fetal ventricular development, which includes frontal horn width (FHW), occipital horn width (OHW), width of 3rd ventricle, cavity of septum pellucidum (CSP), width and length of 4th ventricle and thalamo-occipital distance (TOD) had been measured and analyzed collectively. All data of the indicators was collected on singleton pregnant woman between 16-39 weeks of gestational age (GA), between November 2017 and June 2021 at the Second Hospital of Dalian Medical University. A total of 235 pregnant women were enrolled in the cross section study; another 36 pregnant women voluntarily joined a timeline-tracking follow-up study (cohort study) under the same examining criteria. A decrease of FHW and OHW of the lateral ventricles was observed as GA increased; while dimensional values of TOD, 3rd ventricle, CSP, as well as 4th ventricle increased with GA. Most of these indicators showed an enhanced variation tendency within a certain period of GA. Moreover, values of FHW and TOD showed asymmetry of the two hemispheres within the whole GA. Our findings revealed the morphological regularity of fetal ventricular development, which would instructively enhance the relative clinical ultrasound diagnosis; moreover, TOD also showed regularly changes as GA increased, suggesting that TOD should be considered as an additional routine ultrasonic indicator for fetal ventricular development. [ABSTRACT FROM AUTHOR]

A comparative study of the morphology of suboccipital cavernous sinus (SCS) using MRI and cast specimens was performed. The present retrospective study analysed the craniocervical magnetic resonance venography (MRV) imaging data of 61 patients. Three-dimensional reconstruction was performed using Mimics 19.0. The SCS left-right diameter(d1), distance from the midline (d2), supero-inferior diameter(d3), anteroposterior diameter (d4), distance from posterior diameter to skin (d5), and diameter of the SCS at different parts (d6-d8) were measured. Comparison between MRV images and cast specimens, the SCS, marginal sinus, anterior condylar vein, and vertebral artery venous plexus were symmetrical and could be bilaterally displayed, whereas the presence of extra condylar vein and posterior condylar vein exhibited different types. The adjacency between the SCS and its communicating vessels and changes in its communicating vessels corresponded well with the MRV images and cast specimens. Many types of the presence of left and right lateral condylar and posterior condylar veins were found in the cast specimens, which could be divided into the bilateral presence of posterior condylar and lateral condylar veins, unilateral presence of posterior condylar veins, and unilateral presence of lateral condylar vein. A total of 61 cases analysed using MRV images revealed the bilateral presence of posterior condylar and lateral condylar veins (77.1 %), the unilateral presence of posterior condylar vein (18.0 %), and the unilateral presence of lateral condylar vein (9.8 %), of which the bilateral presence of posterior condylar and lateral condylar veins accounted for the largest proportion. MRV images and cast specimens of the SCS showed its normal morphological structure and adjacency, thus providing accurate and complete Three-dimensional imaging anatomical data of the SCS and its communicating vascular structures. This study enriches the Chinese SCS imaging anatomy data and may be valuable in clinical practice. [ABSTRACT FROM AUTHOR]

The atlanto-occipital joint is composed of the superior fossa of the lateral masses of the atlas (C1) and the occipital condyles. Congenital Atlanto-occipital fusion (AOF) involves the osseous union of the base of the occiput (C0) and the atlas (C1). AOF or atlas occipitalization/assimilation represents a craniovertebral junction malformation (CVJM) which can be accompanied by other cranial or spinal malformations. AOF may be asymptomatic or patients may experience symptoms from neural compression as well as limited neck movement. The myodural bridge (MDB) complex is a dense fibrous structure that connects the suboccipital muscular and its related facia to the cervical spinal dura mater, passing through both the posterior atlanto-occipital and atlanto-axial interspaces. It is not known if atlas occipitilization can induce structural changes in the MDB complex and its associated suboccipital musculature. The suboccipital region of a cadaveric head and neck specimen from an 87-year-old Chinese male having a congenital AOF malformation with resultant changes to the MDB complex was observed. After being treated with the P45 plastination method, multiple slices obtained from the cadaveric head and neck specimen were examined with special attention paid to the suboccipital region and the CVJM. Congenital atlanto-occipital fusion malformations are defined as partial or complete fusion of the base of the occiput (C0) with the atlas (C1). In the present case of CVJM, unilateral fusion of the left occipital condyle with the left lateral mass of C1 was observed, as well as posterior central fusion of the posterior margin of the foramen magnum with the posterior arch of C1. Also noted was a unilateral variation of the course of the vertebral artery due to the narrowed posterior atlanto-occipital interspace. Surprisingly, complete agenesis of the rectus capitis posterior minor (RCPmi) and the obliques capitis superior (OCS) muscles was also observed in the plastinated slices. Interestingly, the MDB, which normally originates in part from the RCPmi muscle, was observed to originate from a superior bifurcation within an aspect of the nuchal ligament. Therefore, the observed changes involving the MDB complex appear to be an effective compensation to the suboccipital malformations. [ABSTRACT FROM AUTHOR]

Myodural bridges (MDB) are anatomical connections between the suboccipital muscles and the cervical dura mater which pass through both the atlantooccipital and the atlantoaxial interspaces in mammals. In our previous studies, we found that the MDB exists in seven terrestrial mammal species, two marine mammal species, two reptilian species, and one bird species. A recent study suggested that given the “ubiquity” of myodural bridges in terrestrial vertebrates, the MDB may also exist in snakes. Specifically, we focused on the Gloydius shedaoensis, a species of Agkistrodon (pit viper snake) that is only found on Shedao Island, which is in the southeastern sea of Dalian City in China. Six head and neck cadaveric specimens of Gloydius shedaoensis were examined. Three specimens were used for anatomical dissection and the remaining three cadaveric specimens were utilized for histological analysis. The present study confirmed the existence of the MDB in the Gloydius shedaoensis. The snake’s spinalis muscles originated from the posterior edge of the supraoccipital bones and the dorsal facet of the exocciput, and then extended on both sides of the spinous processes of the spine, merging with the semispinalis muscles. On the ventral aspect of this muscular complex, it gave off fibers of the MDB. These MDB fibers twisted around the posterior margin of the exocciput and then passed through the atlantooccipital interspace, finally terminating on the dura mater. We observed that the MDB also existed in all of the snakes’ intervertebral joints. These same histological findings were also observed in the Gloydius brevicaudus, which was used as a control specimen for the Gloydius shedaoensis. In snakes the spinal canal is longer than that observed in most other animals. Considering the unique locomotive style of snakes, our findings contribute to support the hypothesis that the MDB could modulate cerebrospinal fluid (CSF) pulsations. [ABSTRACT FROM AUTHOR]

Study Design: A scanning electron microscopic study performed on three cadaveric specimens focused on the human suboccipital region, specifically, myodural bridge (MDB).Objective: This study showed the connection form of the MDB among the suboccipital muscles, the posterior atlanto-occipital membrane (PAOM) and the spinal dura mater (SDM), and provided an ultrastructural morphological basis for the functional studies of the MDB.Summary Of Background Data: Since the myodural bridge was first discovered by Hack, researches on its morphology and functions had been progressing continuously. However, at present, research results about MDB were still limited to the gross anatomical and histological level. There was no research report showing the MDB's ultrastructural morphology and its ultrastructural connection forms between PAOM and SDM.Methods: A scanning electron microscope (SEM) was used to observe the connection of myodural bridge fibers with PAOM and SDM in atlanto-occipital and atlanto-axial interspaces, and the connection forms were analyzed.Results: Under the SEM, it was observed that there were clear direct connections between the suboccipital muscles and the PAOM and SDM in the atlanto-occipital and atlanto-axial spaces. These connections were myodural bridge. The fibers of the myodural bridge merged into the spinal dura mater and gradually became a superficial layer of the spinal dura mater.Conclusion: MDB fibers merged into the SDM and became part of the SDM in the atlanto-occipital and atlanto-axial space. MDB could transfer tension and pulling force to the SDM effectively, during the contraction or relaxation of the suboccipital muscles.Level Of Evidence: N/A. [ABSTRACT FROM AUTHOR]

The myodural bridge (MDB) is confirmed that connecting the most of suboccipital muscles to the cervical dura mater through the posterior intervertebral spaces and widely exists in mammals and birds. In order to reveal whether the MDB is universally existing in amniota of vertebrates, we explored the existence and the morphological features of the MDB in the Trachemys scripta elegans. Twenty fresh red-eared slider specimens were observed by the gross anatomy dissection and histological analysis. In the results, three kind of muscles in the postoccipital region of the red-eared slider were found. The rectus capitis dorsum minor muscle originated from the posterior margin of the occiput (C0) and terminated at the spinous process of the atlas (C1). The transversospinales muscle was attached to the vertebral arch and the postzygapophysis of the atlas and extended to the spinous process of the axis (C2). The C2-C3 intertransversales muscle were extended from the postzygapophysis of C2 and the one of C3. The three muscles covered the dorsal interspaces among C0-C3, and meantime they were closely connected with dense connective tissues, which filled in these interspaces. Each of these thick dense connective tissue membranes sent off several short and strong fibrous bundles ventrally to merge with the cervical spinal dura mater. Furthermore the connective tissues connecting these muscles with cervical spinal dura mater directly were revealed under the microscopy and they consisted of parallel and intensive collagen fibers with orientation from dorsal to ventral. In conclusion, this study for the first time demonstrated the existence of the MDB in the testudines, in all of the dorsal atlantooccipital, atlantoaxial and C2-C3 intervertebral spaces. Based on our results and comparative anatomical evidences in recent year, it could be inferred that the MDB might be its highly conserved structure in the evolution of amniota. [ABSTRACT FROM AUTHOR]

The deep suboccipital muscles has been shown to connect the spinal dura mater via dense connective tissue termed the myodural bridge (MDB). The MDB has both physiological and clinical implications. Data on morphological and imaging anatomical parameters of the deep suboccipital muscles are scare. In this study, T2-weighted images of rectus capitis posterior major (RCPma) and obliqus capitis inferior (OCI) of 109 healthy adults were obtained by 0-degree sagittal and 30-degree oblique sagittal continuous MRI scanning of the head and neck of the subjects. Sectional area parameters of the RCPma and the OCI were measured. The 0-degree sagittal section was measured with 5 mm bias from the median sagittal plane, the sectional area of the RCPma was 186.34± 55.02 mm2 on the left, and 202.35± 59.76 mm2 on the right. The sectional area of OCI was 221.72± 68.99 mm2 on the left, and 224.92± 61.34 mm2 on the right; At the section with 30-degree bias from the oblique sagittal plane, the sectional area of RCPma was 183.30± 42.24 mm2 in males, and 133.05± 26.44 mm2 in females. The sectional area of OCI was 254.81± 46.20 mm2 in males, and 167.42± 27.85 mm2 in females. Significant sex difference exists in the sectional areas of the RCPma and OCI, the values of the male subjects were predominantly larger (P < 0.05), however there were no age-related significant difference. The sectional area of RCPma is bilateral asymmetric, the RCPma on the right side is larger than that of the left side (P < 0.05), but the OCI is bilaterally symmetric (P >0.05). The MRI image features, imaging anatomical data and sexual dimorphism of the RCPma and the OCI are presented in this study. This imaging anatomical data will be useful for functional and clinical studies on the RCPma, OCI, and the MDB. [ABSTRACT FROM AUTHOR]

Objective We aimed to investigate the morphological changes and potential correlation between chronic headaches and the rectus capitis posterior minor muscle (RCPmi). Methods Comparison of RCPmi between patients with chronic headaches and healthy adult volunteers were collected using magnetic resonance imaging (MRI) and Mimics software. Results Among the 235 MRI images analyzed, the data between the two groups were considered statistically significant. The number of males was larger than that of females ( p < 0.001) and the headache group showed greater hypertrophy than the control group in both males ( p < 0.001) and females ( p = 0.001). Conclusions Chronic headaches were correlated with the RCPmi. Patients with chronic headaches suffered from more obvious hypertrophy than that of the control group. Additionally, it was supposed that RCPmi hypertrophy may be one pathogenesis of the chronic headaches. [ABSTRACT FROM AUTHOR]

The past findings confirm that the Rectus Capitis Posterior minor (RCPmi) is connected to the cervical spinal dura mater via the Myodural Bridge (MDB) through the posterior antlanto-occipital interspace. It is hypothesized to perform some functions. Furthermore, some clinical studies found that the pathology of RCPmi might be related to chronic headaches. But few studies were related to the morphological parameters of the RCPmi. It would be conducive to performing clinical researches on the RCPmi and MDB. To explore the optimal section for measuring the RCPmi by MRI and provide imaging anatomy parameters of the RCPmi for clinical research. The RCPmi was measured in the dissection of 10 formalin-fixed cadaver specimens. The morphological parameters of the RCPmi were obtained. Based on these parameters, T2-weighted images of the RCPmi were collected from 109 healthy adults by using the MRIs with different oblique sagittal scanning angles. The parameters of length and area of the RCPmi on the scanning sections were measured using MRI workstation and Mimics software. The length of RCPmi reached a maximum at 30 degrees scanning leaned from the posterior median line through the dens of the axis in oblique sagittal section. At this scanning section, the length of RCPmi was 21.2 ± 2.6 mm in males and 19.3 ± 2.4 mm in females and the area of RCPmi was 91.9 ± 27.2 mm2 in males and 73.3 ± 22 mm2 in females. These parameters of RCPmi were present with significant gender differences (P < 0.05) but was not age related. Thirty degrees leaned from the median line was suggested to be the optimum scanning angle to display the RCPmi in oblique sagittal section. The reference values of length and area of the RCPmi were established for studies of hypertrophy or amyotrophy of the RCPmi. [ABSTRACT FROM AUTHOR]

Objective: Myodural bridge complex (MDBC) is a new functional complex structure including the rectus capitis dorsal minor (RCDmi), rectus capitis posterior major (RCPma), obliquus capitis inferior (OCI), nuchal ligament (NL), vertebrodural ligament (VDL) and dense MDB fibers originate from these muscles and ligaments. We firstly proposed that the MDBC could be a significant contributor to CSF (Cerebrospinal Fluid) dynamics at the craniocervical junction in addition to other factors such as heartbeat and respiration. MDBC was found to exist in the vast majority of studied amphibians, birds, reptiles and mammals in our study. It was considered as an evolutionarily conserved structure. During the landing process of the vertebrates, the morphological evolution process of MDBC and its regulatory mechanism that adapt to the terrestrial living environment remains unclear. Methods: Anatomical, multiple histologic staining methods and scanning electron microscopy observation were used in the present study to compare and analyze the morphological differences among the MDBC in different animals. Results: It was found that MDBC/MDBC-like structures widely existed in vertebrates. It was also found that MDBC/MDBC-like structures exist throughout the vertebral tubes in fish, but for amphibians, birds, reptiles and mammals, the MDBC is concentrated in the cervical vertebral segments. Conclusion: Our study implies that the transformation of amphibian MDBC/MDBC-like structures might be an adaptive change in the evolution of the vertebrate from water to land. [ABSTRACT FROM AUTHOR]