Twisted orientation of the muscle bundles in the levator ani functional parts in women: Implications for pelvic floor support mechanism.

This study presents a comprehensive investigation of the anatomical features of the levator ani muscle. The levator ani is a critical component of the pelvic floor; however, its intricate anatomy and functionality are poorly understood. Understanding the precise anatomy of the levator ani is crucial for the accurate diagnosis and effective treatment of pelvic floor disorders. Previous studies have been limited by the lack of comprehensive three-dimensional analyses; to overcome this limitation, we analysed the levator ani muscle using a novel 3D digitised muscle-mapping approach based on layer-by-layer dissection. From this examination, we determined that the levator ani consists of overlapping muscle bundles with varying orientations, particularly in the anteroinferior portion. Our findings revealed distinct muscle bundles directly attached to the rectum (LA-re) and twisted muscle slings surrounding the anterior (LA-a) and posterior (LA-p) aspects of the rectum, which are considered functional parts of the levator ani. These results suggest that these specific muscle bundles of the levator ani are primarily responsible for functional performance. The levator ani plays a crucial role in rectal elevation, lifting the centre of the perineum and narrowing the levator hiatus. The comprehensive anatomical information provided by our study will enhance diagnosis accuracy and facilitate the development of targeted treatment strategies for pelvic floor disorders in clinical practice.

Retroperitoneal fasciae as barriers for nerve and arterial passages connecting the retroperitoneal region to the peritoneal organs.

The fascia of the pancreatic head is referred to as the retropancreatic fascia of Treitz, and that of the body and tail of the pancreas is named the retropancreatic fascia of Toldt. However, the spatial relationship between the nerves, fascia, and the distribution of the fascia on the dorsal side of the pancreas remains unclear. Therefore, this study aimed to explore the distribution of these fasciae and elucidate the spatial relationship between the nerves and arteries connecting the retroperitoneal space and the peritoneal organs by studying eight cadavers using macroscopic anatomical examination, wide-range serial sectioning, and three-dimensional reconstruction. The fasciae of Treitz and Toldt converge caudally to the root of the superior mesenteric artery (SMA), forming a narrower gap around the roots of the celiac trunk and SMA than in the celiac plexus. The fasciae eventually get closer to each other, and the boundary between them becomes obscured, providing coverage to the anterior surface of the aorta between the SMA and the inferior mesenteric artery. The celiac plexus does not penetrate the fascia but converges before spreading into the pancreas. Similarly, the arteries pass through this gap in the fasciae. Our findings suggest that the retroperitoneal space and peritoneal organs are connected through a narrow no-fascia area, with the distribution of the fascia relating to nervous and vascular pathways. Our findings reveal that the distribution of the avascular plane may provide a crucial anatomical foundation for abdominal digestive organ surgery by reducing bleeding volume and determining the dissection region.

Capsular attachment on the anterosuperior femoral head-neck junction: A hypothesis about femoroacetabular impingement.

Femoroacetabular impingement (FAI), characterized by a pathological contact between the proximal femur and acetabulum, is a common precursor of hip osteoarthritis. Cam morphology is a bony prominence that causes FAI and frequently forms on the anterosuperior femoral head-neck junction. Despite anatomical consensus regarding the femoral head-neck junction as a boundary area covered by the articular cartilage and joint capsule, it remains unclear whether the joint capsule is continuous with the anterosuperior articular cartilage. For the anatomical consideration of cam morphology formation, this study aimed to investigate the histological characteristics of the capsular attachment on the anterosuperior femoral head-neck junction, particularly focusing on the presence or absence of continuity of the joint capsule to the articular cartilage. A total of 21 anterosuperior regions (seven hips each for the 12:00, 1:30, and 3:00 positions) from seven hips (three males and four females; mean age at death, 68.7 years) were histologically analyzed in this study for quantitative evaluation of the capsular thickness using histological sections stained with Masson's trichrome, as well as qualitative evaluation of the capsular attachment. The present study showed that the joint capsule, which folded proximally to the femoral head-neck junction from the recess, exhibited a blend of the fibrous and synovial regions. Notably, it not only continued with the superficial layer of the articular cartilage, but also attached to the articular cartilage via the fibrocartilage. This continuous region was relatively fibrous with dense connective tissue running in the longitudinal direction. The capsular thickness at the recess point (mean, 1.7 ± 0.9 mm) and those at the distal end of the articular cartilage (0.35 ± 0.16 mm) were significantly greater than the control value for the most superficial layer thickness of the articular cartilage (0.019 ± 0.003 mm) (Dunnett's T3, both p-value <0.001). Based on the fibrous continuity between the joint capsule and articular cartilage and its thickness, this study suggests the anatomical possibility that some mechanical stress can be transmitted from the joint capsule to the articular cartilage at the frequent sites of cam morphology.

Denonvilliers' fascia as a potential nerve-course marker for the female urinary bladder.

OBJECTIVES: This study investigated the relationship between Denonvilliers' fascia (DF) and the pelvic plexus branches in women and explored the possibility of using the DF as a positional marker in nerve-sparing radical hysterectomy (RH). METHODS: This study included eight female cadavers. The DF, its lateral border, and the pelvic autonomic nerves running lateral to the DF were dissected and examined. The pelvis was cut into two along the mid-sagittal line. The uterine artery, deep uterine veins, vesical veins, and nerve branches to the pelvic organs were carefully dissected. RESULTS: The nerves ran sagitally, while the DF ran perpendicularly to them. The rectovaginal ligament was continuous with the DF, forming a single structure. The DF attached perpendicularly and seamlessly to the pelvic plexus. The pelvic plexus branches were classified into a ventral part branching to the bladder, uterus, and upper vagina and a dorsal part branching to the lower vagina and rectum as well as into four courses. Nerves were attached to the rectovaginal ligament and ran on its surface to the bladder ventral to the DF. The uterine branches split from the common trunk of these nerves. The most dorsal branch to the bladder primarily had a common trunk with the uterine branch, which is the most important and should be preserved in nerve-sparing Okabayashi RH. CONCLUSION: The DF can be used as a marker for nerve course, particularly in one of the bladder branches running directly superior to the DF, which can be preserved in nerve-sparing Okabayashi RH.

Anatomy of muscle connections in the male urethra and anorectal canal.

OBJECTIVES: To elucidate the male urethral muscular structure and its relationship with the anorectal canal muscles, as establishing an anatomical foundation for urethral function will contribute to the prevention, diagnosis, and treatment of urinary incontinence. METHODS: Eight male cadavers were used. Using a multifaceted approach, we performed macroscopic anatomical examination, histological analysis of wide-range serial sectioning and immunostaining, and three-dimensional (3D) reconstruction from histological sections. In the macroscopic anatomical examination, pelvic halves were meticulously dissected in layers from the medial aspect. In the histological analysis, the tissue, including the urethra and anorectal canal, was serially sectioned in the horizontal plane. The muscular structures were reconstructed and visualised in 3D. RESULTS: The membranous portion of the urethra had three muscle layers: the longitudinal and circular muscles (smooth muscle) and the external urethral sphincter (skeletal muscle). The circular muscle was connected posteriorly to the longitudinal rectal muscle. The external urethral sphincter had a horseshoe shape, with its posterior ends continuing to the external anal sphincter, forming a 3D ring-like sphincter. CONCLUSION: This study revealed skeletal and smooth muscle connections between the male urethra and anorectal canal, enabling urethral compression and closure. These anatomical muscle connections suggest a functional linkage between them.

In vivo interrelationships between the gluteus minimus and hip joint capsule in the hip internal rotation position with flexion.

BACKGROUND: The flexion adduction internal rotation (FADIR) test is performed by the combined motions of hip flexion (with knee flexion), adduction, and internal rotation, and can often reproduce anterior hip pain consistent with an individual's presenting pain. Since it has high sensitivity for intraarticular pathology diagnosis but low specificity, understanding the extraarticular pathology that can induce anterior hip pain in the FADIR test may also be essential. This study hypothesized that the interrelationships between the joint capsule and gluteus minimus differ in individuals with and without FADIR-positive pain and aimed to elucidate the in vivo interrelationships at hip internal rotation in 90°-flexion, which is also often restricted in individuals with FADIR-positive pain. METHODS: Ten hips were included in the FADIR-positive group, and ten hips without hip pain in the FADIR test were included in a control group. Based on the ultrasound images at the four hip rotation conditions (20° and 10° external rotations, 0° external/internal rotation, and 10° internal rotation), orientation measurements of the gluteus minimus (muscle belly portion) and joint capsule were performed and quantitatively compared between the FADIR-positive and control groups. Additionally, 3 hips of 3 participants were randomly selected from each of the control and FADIR-positive groups for magnetic resonance imaging analysis. RESULTS: At 0°-external/internal and 10°-internal rotation, on ultrasound images, fibers of the gluteus minimus and joint capsule in the FADIR-positive group were significantly more oriented in the same direction than those in the control group. Magnetic resonance imaging showed that the loose connective tissue between the gluteus minimus and joint capsule was prominent at 10°-internal rotation in the control group, although this was not apparent in the FADIR-positive group. CONCLUSIONS: At hip internal rotation in 90° flexion, the muscular belly portion of the gluteus minimus and joint capsule were oriented in the same direction to a greater extent in the FADIR-positive group than in the control group owing to a morphological change in the loose connective tissue between them. The pathological changes in the loose connective tissue may inhibit smooth movement of the gluteus minimus relative to the joint capsule in individuals with FADIR-positive pain.

Three-dimensional Analysis of the Muscles Related to the So-Called "Pterygomandibular Raphe": An Anatomical and Histological Study.

The pterygomandibular raphe (PMR) is a tendinous bundle between the bucinator (BM) and the superior constrictor of pharynx (SC) and has been considered essential for swallowing. Despite its functional significance, previous studies reported that the PMR is not always present. Another study reported presence of the connecting fascia between the BM and deep temporalis tendon (dTT). Therefore, the present study analyzed the three-dimensional relationship between the BM, SC, and dTT. We examined 13 halves of 11 heads from adult Japanese and Caucasian cadavers: eight halves macroscopically and five halves histologically. There was no clear border between the BM and SC in any specimens macroscopically. The BM attachment varied depending on its levels. At the level of the superior part of the internal oblique line, the BM fused with the SC with no clear border. At the level of the midpart of the internal oblique line of the mandible, the BM attached to the dTT directly, and the SC attached to the dTT via collagen fibers and the BM. Based on these results, these muscles should be described as the BM/dTT/SC (BTS) complex. The three-dimensional relationship of the BTS complex might result in the so-called "pterygomandibular raphe." The BTS complex could be important as a muscle coordination center in chewing and swallowing.

Anatomical basis for contribution of hip joint motion by the obturator internus to defaecation/urinary functions by the levator ani via the obturator fascia.

The functional association between hip joint motion and defaecation/urinary function has attracted considerable research and clinical attention owing to the potential novel approaches for pelvic floor rehabilitation; however, the anatomical basis remains unclear. This study, therefore, aimed to analyse the anatomical basis of force transmission between the obturator internus, a muscle of the hip joint, and the levator ani, a muscle of the pelvic floor. Twenty-three cadavers were used for macroscopic and histological analyses. The three-dimensional structures of the muscles and fascia were recorded using a high-definition camera and a 3D scanner. The arrangement and attachment of the muscle fibres, tendons and fascia were visualised using histological sections stained with Masson's trichrome. The obturator internus and levator ani were in broad contact through the obturator fascia. The height of their contact area was 24.6 ± 9.1 mm. Histologically, the obturator internus and levator ani shared a large area of the obturator fascia, and the obturator fascia provided the attachment of several muscle layers of the levator ani. The contribution of hip joint motion to defaecation/urinary function can be explained by the broad 'planar' contact between the obturator internus and levator ani. This anatomical feature suggests that movement of the obturator internus creates the foundation for the function of the levator ani and contributes to pelvic floor support through the obturator fascia. This study provides an anatomical basis for the effectiveness of the hip muscles in improving defaecation/urinary function by enabling balanced and proper movements.

Surgical anatomy of the dorsal pancreatic artery: Considering embryonic development.

OBJECTIVES: The dorsal pancreatic artery (DPA) is a pancreatic branch with various anatomical variations. Previous studies mostly focused on the origin of the DPA, and its pathways and branching patterns have rarely been examined. The purpose of this study was to investigate the branching patterns and pathways of the DPA. METHODS: This study included 110 patients who underwent computed tomography scans. We examined the pathways and branching patterns of the DPA. RESULTS: The DPA was identified in 101 patients (92%), and originated from the splenic artery in 30 patients (31%), the common hepatic artery in 17 patients (17%), the celiac trunk in 10 patients (10%), the superior mesenteric artery in 27 patients (27%), the replaced right hepatic artery in 7 patients (7%), the inferior pancreaticoduodenal artery in 5 patients (5%), and other arteries in 3 patients (3%). Four distinct types of branches were identified as follows: the superior branch (32%), the inferior branch (86%), the right branch (80%), and the accessory middle colic artery (12%). Additionally, the arcs of Buhler and Riolan were observed in two patients each and their anastomotic vessels followed almost the same pathway as the DPA. CONCLUSION: A number of variations of the DPA were observed with regard to its origin and branching pattern; however, the DPA and its branches always ran along the same pathway, as summarized in Fig. 4. The anatomical information gained from this study may contribute to performing safe pancreatic resections.

High diagnostic accuracy of magnetic resonance imaging in detecting subscapularis tendon tears by focusing on the most superior portion of the subscapularis tendon.

PURPOSE: This study aimed to test the hypothesis that identifying the exact location of the most superior portion of the subscapularis tendon using magnetic resonance imaging (MRI) provides high diagnostic accuracy in detecting subscapularis tendon tears. METHODS: This study included 157 patients who underwent primary arthroscopic rotator cuff repair between 2014 and 2017. All patients underwent conventional 1.5-T MRI in our hospital, within 3 months before surgery. We retrospectively compared the diagnosis of subscapularis tendon tears using MRI based on an anatomical concept focusing on the superior-most insertion point of the subscapularis tendon with intraoperative arthroscopic findings. RESULTS: Subscapularis tendon tears were detected in 80 (51.0%) of the 157 patients during arthroscopic evaluation. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the MRI examination were 90, 83, 85, 89, and 87%, respectively. With a kappa score of 0.83, the concordance rate between the two raters was almost perfect (95% confidence interval, 0.75-0.92). The sensitivities of the oblique-sagittal and axial sequences were 84 and 79%, respectively. CONCLUSIONS: Preoperative MRI evaluation focusing on the most superior portion of the subscapularis tendon demonstrated high diagnostic accuracy in detecting subscapularis tendon tears. To find the most superior portion of the subscapularis tendon tears, it was essential to check the slice at the level of the lesser tubercle tip and its adjacent slice. In addition, the combined observation of oblique-sagittal and axial sequences helped to detect subscapularis tendon tears with higher sensitivity.

Basic Consideration for Facial Aging: Age-Related Changes of the Bony Orbit and Orbicularis Oculi Muscle in East Asians.

BACKGROUND: Age-related changes in the periocular areas are mainly caused by anatomic changes of the bony orbit and orbicularis oculi muscle (OOM). To achieve effective rejuvenation, it is necessary to understand the age-related aspects of these anatomic changes. OBJECTIVES: The aim of this study was to analyze the configuration of the bony orbit and OOM with computed tomography (CT) and to evaluate the effects of aging on these structures. METHODS: A total of 220 orbits and OOMs of 110 Japanese participants (55 males, 55 females) aged 20 to 87 years were enrolled. The long diameter of the orbits, orbital ellipticity, OOM thickness, and OOM attachment to the inferior orbital rim were analyzed. These variables were statistically evaluated for their relationship with age. RESULTS: The long diameter of the orbit was significantly longer in those over than in those under 60 years, with a moderate and significant positive correlation between orbital ellipticity and age. OOM thickness and age showed a strong negative correlation. The degree of OOM attachment to the inferior orbital rim decreased significantly with age. CONCLUSIONS: This study showed that age-related changes of the bony orbit in Japanese individuals tended to be the same as those in Caucasians, but there were differences in the degree of changes observed. As a new finding in the Japanese population, the OOM not only thins with aging, but also gradually loosens from the facial bone. In the elderly, only the nasal side of the OOM was attached to the bone. In clinical applications, this knowledge could contribute to the development of cosmetic surgeries.

The Use of the Deep Brachial Artery as the Recipient Artery for Free Perforator Flap Transfer: An Anatomic Study and Clinical Applications.

Background and Objectives: Soft tissue reconstruction after sarcoma ablation in the posterior aspect of the upper arm has been commonly addressed using the pedicled latissimus dorsi musculo-cutaneous flap. The use of a free flap for coverage of this region has not been reported in detail. The goal of this study was to characterize the anatomical configuration of the deep brachial artery in the posterior upper arm and assess its clinical utility as a recipient artery for free-flap transfers. Materials and Methods: In total, 18 upper arms from 9 cadavers were used for anatomical study to identify the deep brachial artery's origin and point of crossing the x-axis, which was set from the acromion to the medial epicondyle of the humerus. Measurements of the diameter were taken at each point. The anatomic findings of the deep brachial artery were employed clinically in the reconstruction of the posterior upper arm after sarcoma resection using free flaps in 6 patients. Results: The deep brachial artery was found in all specimens between the long head and the lateral head of the triceps brachii muscle, and it crossed the x-axis at an average distance of 13.2 ± 2.9 cm from the acromion, with an average diameter of 1.9 ± 0.49 mm. In all 6 clinical cases, the superficial circumflex iliac perforator flap was transferred to cover the defect. The average size of the recipient artery, the deep brachial artery, was 1.8 mm (range, from 1.2 to 2.0 mm). The average diameter of the pedicle artery, the superficial circumflex iliac artery, was 1.5 mm (range, from 1.2 to 1.8 mm). All flaps survived completely with no postoperative complications. Conclusions: The deep brachial artery can be a reliable recipient artery in free-flap transfers for posterior upper arm reconstruction, given its anatomical consistency and sufficient diameter.

Histological study of the thin membranous dense connective tissues around the curving portion of the bilateral recurrent laryngeal nerves.

OBJECTIVE/AIM: We aimed to demonstrate the anatomical relationship between the recurrent laryngeal nerves (RLNs), thin membranous dense connective tissue (TMDCT [e.g., the visceral or vascular sheaths around the esophagus]), and the lymph nodes around the esophagus at the curving portion of the RLNs for rational and efficient lymph node dissection. METHODS: Transverse sections of the mediastinum at 5 mm or 1 mm intervals were obtained from four cadavers. Hematoxylin and eosin staining and Elastica van Gieson staining were performed. RESULTS: The visceral sheaths could not be clearly observed the curving portions of the bilateral RLNs, which were observed on the cranial and medial side of the great vessels (aortic arch and right subclavian artery [SCA]). The vascular sheaths could be clearly observed. The bilateral RLNs diverged from the bilateral vagus nerves, which ran along with the vascular sheaths, went up around the caudal side of the great vessels and the vascular sheath, and ran cranially on the medial side of the visceral sheath. Visceral sheaths were not observed around the region containing the left tracheobronchial lymph nodes (No. 106tbL) or the right recurrent nerve lymph nodes (No. 106recR). The regions containing the left recurrent nerve lymph nodes (No. 106recL) and the right cervical paraesophageal lymph nodes (No. 101R) were observed on the medial side of the visceral sheath, with the RLN. CONCLUSION: The recurrent nerve, which branched off from the vagus nerve descending along the vascular sheath, ascended the medial side of the visceral sheath after inversion. However, no clear visceral sheath could be identified in the inverted area. Therefore, during radical esophagectomy, the visceral sheath along No. 101R or 106recL may be recognized and available.

Ovotesticular disorders of sex development in FGF9 mouse models of human synostosis syndromes.

In mice, male sex determination depends on FGF9 signalling via FGFR2c in the bipotential gonads to maintain the expression of the key testis gene SOX9. In humans, however, while FGFR2 mutations have been linked to 46,XY disorders of sex development (DSD), the role of FGF9 is unresolved. The only reported pathogenic mutations in human FGF9, FGF9S99N and FGF9R62G, are dominant and result in craniosynostosis (fusion of cranial sutures) or multiple synostoses (fusion of limb joints). Whether these synostosis-causing FGF9 mutations impact upon gonadal development and DSD etiology has not been explored. We therefore examined embryonic gonads in the well-characterized Fgf9 missense mouse mutants, Fgf9S99N and Fgf9N143T, which phenocopy the skeletal defects of FGF9S99N and FGF9R62G variants, respectively. XY Fgf9S99N/S99N and XY Fgf9N143T/N143T fetal mouse gonads showed severely disorganized testis cords and partial XY sex reversal at 12.5 days post coitum (dpc), suggesting loss of FGF9 function. By 15.5 dpc, testis development in both mutants had partly recovered. Mitotic analysis in vivo and in vitro suggested that the testicular phenotypes in these mutants arise in part through reduced proliferation of the gonadal supporting cells. These data raise the possibility that human FGF9 mutations causative for dominant skeletal conditions can also lead to loss of FGF9 function in the developing testis, at least in mice. Our data suggest that, in humans, testis development is largely tolerant of deleterious FGF9 mutations which lead to skeletal defects, thus offering an explanation as to why XY DSDs are rare in patients with pathogenic FGF9 variants.

Medial patellofemoral ligament is a part of the vastus medialis obliquus and vastus intermedius aponeuroses attaching to the medial epicondyle.

PURPOSE: This study aimed to investigate the bony surface characteristic of the femoral attachment of the medial patellofemoral ligament (MPFL) and the correlation between the relevant layered structures, including muscular aponeurosis and the joint capsule, which contribute to patellofemoral joint (PFJ) stability. METHODS: The morphology of the medial aspect of the medial condyle using micro-computed tomography and analysed cortical bone thickening in 24 knees was observed. For the macroscopic and histological analyses, 21 and 3 knees were allocated, respectively. The Kruskal-Wallis one-way analysis of variance test with Dunn post hoc testing was performed for statistical analysis. RESULTS: At the level of the adductor tubercle, there were no significant differences in cortical bone thickness. At the level of the medial epicondyle (MEC), cortical bone thickness was considerably greater than that in other areas of the medial condyle (mean ± standard deviation, 0.60 ± 0.20 mm; p < 0.0001). Macroscopic analysis revealed that the deep aponeurosis of the vastus medialis obliquus and the tendinous arch of the vastus intermedius distally formed the composite membrane and adjoined to the joint capsule to firmly attach to MEC, which was located at 41.3 ± 5.7 mm posterior and 14.2 ± 3.1 mm superior to the joint cartilage. Histological analysis showed a composite membrane and adjoining capsule attached to MEC via fibrocartilage. CONCLUSION: MPFL could be interpreted as part of the deep aponeurosis of the vastus medialis obliquus (VMO) and the tendinous arch of the vastus intermedius, which combined with the joint capsule to attach to MEC. The cortical bone thickening indicated that the tensile stresses were loaded on MEC in aged cadavers. Involvement of VMO and vastus intermedius aponeuroses in restored graft of MPFL could utilise the dynamic stability of surrounding muscles to mimic a native structure.

An Anatomical Study of Posterior Trunk Recipient Vessels, and Comparisons of Outcome following Pedicled- and Free-Flap Transfers for Treatment of Sarcoma in the Posterior Trunk.

BACKGROUND: Reconstruction after wide resection of a large sarcoma arising in the posterior trunk may require free-flap transfer to reduce the postoperative complications. Here, we describe the recipient vessels on the whole posterior trunk. Moreover, to show the reliability of these vessels, we describe an institutional series of free-flap reconstruction. METHODS: In the cadaveric study, 20 posterior trunk regions from 10 fixed cadavers were dissected. The location and the diameter of the perforating artery and vein on the posterior were documented. In the clinical study, 54 patients undergoing immediate reconstruction surgery with only a pedicled flap (n = 45) and with a free flap (n = 9) after sarcoma resection on the posterior trunk between July 2005 and September 2021 were identified. One-to-one propensity score matching was performed to compare the postoperative complications. RESULTS: In the cadaveric study, a total of 178 perforators were identified. The average diameter of the superficial cervical artery (SCA) and vein, dorsal scapular artery (DSA) and vein, medial branch of dorsal intercostal artery perforator (m-DICAP) and vein, lateral branch of dorsal intercostal artery perforator (l-DICAP) and vein, and dorsolateral intercostal artery perforator (DLICAP) and vein were 1.03, 1.67, 1.38, 1.84, 1.28, 1.84, 1.01, 1.60, 1.11, and 1.70 mm. In the clinical study, the propensity score-matched analysis involving eight pairs showed a significantly higher occurrence of total complications in the pedicled-flap group than the free-flap group (62.5 vs. 0%, p = 0.03). CONCLUSION: The cadaveric study showed that the perforators from the SCA, DSA, and posterior intercostal artery are constantly present. The clinical study demonstrated the feasibility and reliability of a free-flap transfer.

Anatomic and diagnostic considerations of facial mobility for understanding the effectiveness of facial massage: A pilot study.

BACKGROUND: The effectiveness of facial massage is often explained by the resulting increases in the blood and lymphatic flow. However, it is difficult to explain the lifting effect on the cheeks. The aim of this study was to analyze facial mobility to further current understanding of the effectiveness of facial massage. MATERIALS AND METHODS: Two kinds of analytical methods were designed using a cadaveric head as well as advanced computed tomography (CT). The cadaveric face was divided into three sections, and three different colors of ink were injected into each section. It was kept in a supine position for 24 hours, and the ink distribution was observed. Upright and supine CT examinations were performed on six healthy adult volunteers. The images of both were superimposed by a three-dimensional image analysis system, and changes in facial contours were analyzed. RESULTS: The three colors of ink spread craniocaudally and were distributed differently from the gravitational vector. When both CT images were superimposed, two distinct lines were formed, which represented overlapping of the facial contours due to the two different CT images. These lines were found to correspond to the border of each color of the ink. CONCLUSION: Focusing on the mobility of the face, the soft tissue of the face had vertical mobility, and it was speculated that this mobility is involved in the effectiveness of facial massage. Our results could provide useful information for cosmetic treatment and contribute to the collection of scientific knowledge for anti-aging medicine.

Anatomy of inferior end of palatopharyngeus: its contribution to upper esophageal sphincter opening.

PURPOSE: The palatopharyngeus is one of the longitudinal pharyngeal muscles which contributes to swallowing. It is reported that the palatopharyngeus has muscle bundles in various directions and with attachment sites, and each muscle bundle has a specific function. Although previous reports suggest that the palatopharyngeus is partly interlaced with some parts of the inferior constrictor, the precise relationship remains unclear. The purpose of this study was to examine the precise manner of the connection between the palatopharyngeus and inferior constrictor, and to examine the histological characteristics of this connection. METHODS: We examined 15 halves of nine heads from Japanese cadavers (average age: 76.1 years); 12 halves, macroscopically, and three halves, histologically. RESULTS: Our observation suggests that the palatopharyngeus spreads radially on the inner aspect of the pharyngeal wall. The most inferior portion of the palatopharyngeus extended to the inner surface of the cricopharyngeal part of the inferior constrictor. Histological analysis showed that the inferior end of the palatopharyngeus continued into the dense connective tissue located at the level of the cricoid cartilage. The dense connective tissue not only covered the inner surface of the inferior constrictor but also entered its muscle bundles and enveloped them. CONCLUSION: Therefore, the palatopharyngeus interlaced the cricopharyngeal part of the inferior constrictor through the dense connective tissues. The findings of this study show that the palatopharyngeus may act on the upper esophageal sphincter directly and help in its opening with the aid of the pulling forces in the superolateral direction.

The series of smooth muscle structures in the pelvic floors of men: Dynamic coordination of smooth and skeletal muscles.

INTRODUCTION: Recent studies have revealed the extended nature of smooth muscle structures in the pelvic floor, revising the conventional understanding of the "perineal body." Our aim was to clarify the three-dimensional configuration and detailed histological properties of the smooth muscle structures in the region anterior to the rectum and anal canal in men. MATERIALS AND METHODS: Four male cadavers were subjected to macroscopic and immunohistological examinations. The pelvis was dissected from the perineal side, as in the viewing angle during transperineal surgeries. Serial transverse sections of the region anterior to the rectum and anal canal were stained with Masson's trichrome and immunohistological stains to identify connective tissue, smooth muscle, and skeletal muscle. RESULTS: There was a series of smooth muscle structures continuous with the longitudinal muscle of the rectum in the central region of the pelvic floor, and three representative elements were identified: the anterior bundle of the longitudinal muscle located between the external anal sphincter and bulbospongiosus; bilateral plate-like structures with transversely-oriented and dense smooth muscle fibers; and the rectourethral muscle located between the rectum and urethra. In addition, hypertrophic tissue with smooth muscle fibers extended from the longitudinal muscle in the anterolateral portion of the rectum and contacted the levator ani. CONCLUSIONS: The series of smooth muscle structures had fiber orientations and densities that differed among locations. The widespread arrangement of the smooth muscle in the pelvic floor suggests a mechanism of dynamic coordination between the smooth and skeletal muscles.

Dynamic changes of the joint capsule in relation to the zona orbicularis: An anatomical study with possible implications for hip stability mechanism.

The zona orbicularis, which comprises the inner circular fibers of the joint capsule, is vital for hip stability in distraction. Despite the proximity of the whole joint capsule to the zona orbicularis, their anatomical relationship remains unclear. The aim of this study is to investigate the characteristics of the inner side of the joint capsule comprehensively. Twelve hips from nine bodies donated to science were examined. Six and three of the donated bodies, respectively, were embalmed using 8% formalin and Thiel's method. The joint capsules in three formalin-embalmed bodies were sturied by micro-computed tomography. During formalin fixation of six hips from these three bodies, one side was maintained at hip extension and the other at flexion. The remaining three formalin-embalmed bodies were examined histologically. Micro-computed tomography images revealed that the inward protrusion of the joint capsule narrowed the articular cavity, and the ratio of its narrowest area to that of the femoral neck was less at hip extension than at hip flexion. The Thiel's method specimens showed that the inner surface of the joint capsule protruded inward toward the femoral neck during hip extension. This inward protrusion was not histologically independent of the joint capsule. The zona orbicularis was interpreted as the inward protrusion caused by dynamic change of the joint capsule, rather than the local collar. In other words, the joint capsule could change its morphology dynamically depending on the hip position.