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The frontal sinus is one of the four paranasal sinuses in humans, and knowledge of its anatomy is important when performing surgery involving the frontal bone or sinus. Although many studies have measured the frontal sinus using radiography and computed tomography (CT), few studies have evaluated by using three-dimensional (3D) analysis. The purpose of this study was to analyze the frontal sinus using 3D reconstruction analysis and determine the differences in linear and volumetric measurements between sexes, sides, and ages. The sample comprised 281 facial CT scans: 173 and 108 from males and females, respectively. The width, height, and length of each frontal sinus and total volume were all larger in males than in females. Almost all linear and volumetric measurements were larger in young adults than in older for both sexes, but not all of the differences were statistically significant. Linear and volumetric measurements were larger for males than females regardless of age group. There were no statistically significant differences between the right and left sides except the width in males. The size of the frontal sinus was strongly influenced by sex and age. The measurements reported here might be useful for improving surgical procedures involving the frontal sinus.

The elevator muscles of the upper lip are the levator labii superioris alaeque nasi, levator labii superioris, and zygomaticus minor muscles, which function by means of their insertions into the skin of the upper lip. However, many textbooks and journal articles state that no muscle fibers are present on the orbicularis oris muscle in the upper lip. The authors attempted to determine whether there is a superficial muscle layer in addition to the orbicularis oris muscle in the upper lip.The authors performed gross dissections of 10 formalin-fixed cadavers and applied micro-computed tomography to six formalin-fixed cadavers. The fine dissection of the upper lip was performed in a layer-by-layer manner that elucidated its muscle layers. The entire layer of the upper lip was separated and pretreated with phosphotungstic acid for micro-computed tomography. The samples used for micro-computed tomography were repurposed for use in histologic analysis. An ultrasonography study was also performed.The presence of a muscle layer on the orbicularis oris muscle was confirmed in all samples. The elevator muscle fibers of the upper lip formed a layer by combining with connective tissue. Micro-computed tomography indicated lower terminal insertions of the elevator muscles throughout the upper lip. All parts of the upper lip skin were inserted into the orbicularis oris muscle. The histologic findings were similar to those of micro-computed tomography.The authors' findings could be used to improve aesthetic and surgical procedures performed on the upper lip, such as correction of gummy smile and transverse upper labial crease, or postresection reconstruction of the upper lip.

The facial artery is the main artery supplying blood to the face and is known to have facial branches of the inferior labial, superior labial, lateral nasal and angular arteries. These known major branches of facial artery run medially, however, there are sometimes branches of the facial artery heading laterally. The purpose of the present study was to investigate the lateral branches of the facial artery in face. We dissected facial branches of the facial artery in 74 cadaveric hemifaces. We investigated the presence of the lateral branches of the facial artery. Following parameters were investigated: lateral branch presence, the location of its origin, and the lateral branch diameter. Among the lateral branches, we evaluated the prevalence and diameter of the premasseteric branch. Lateral branches were observed in 48 of the 74 hemifaces (64.9%). The total number was 81 in the 48 hemifaces. The most common origin was between the inferior border of the mandible and inferior labial artery origin (42 of 81, 51.9%). The mean diameter of all lateral branches of the facial artery was 0.7 mm. Among the lateral branches, the premasseteric branches were present in 38 of 74 specimen (51.4%) and the mean diameter was 0.8 mm. The lateral branches of the facial artery may be registered in Terminologia Anatomica based on their prevalence. Accurate knowledge of the anatomy of the lateral branches of the facial artery is helpful for clinicians to avoid complications during facial procedures or maxillofacial surgeries.

Background Retrobulbar filler injection has recently been considered an ideal method for orbital volume enhancement due to its nontoxic, easily reversible, and noninvasive characteristics. This study determined the arterial distribution in the orbit with the aim of defining a safety zone for retrobulbar filler injections used to enhance the orbital volume. Methods Twenty-seven orbits of 24 formalin-embalmed cadavers were dissected. The orbital arteries were identified after removal of the eyeball, extraocular muscles, and connective tissues. The course of each orbital artery was then recorded in each specimen, and all of the courses were then superimposed to determine the arterial distribution in the orbit. Results The superimposition of lined images based on the orbital vasculature of each specimen revealed that the arterial density was highest in the superonasal region and lowest in the inferotemporal region. In particular, orbital arteries were scarce at 8 o'clock and 4 o'clock in the right and left orbits, respectively, and an artery-free zone was demonstrated in the outer part of those directions. Conclusions When performing a transcutaneous retrobulbar injection of filler for orbital volume enhancement, the relative safety zone could be considered to be located at 8 o'clock and 4 o'clock in the right and left orbits, respectively. The detailed topographic information about the arterial distribution in the orbit, provided by the present study, may help oculofacial surgeons to avoid injury to major vessels and decrease the risk of retrobulbar hemorrhage and vision-threatening complications.

The purpose of this study is to identify the location of the orbital part of the lacrimal gland using external landmarks to facilitate effective botulinum toxin A (BTX-A) injections for epiphora treatment. Dissections were performed on 45 hemifaces from 27 cadavers. The length, anterior protrusion, and thickness of the orbital part of the lacrimal gland were measured directly. The midpoint of the line running horizontal through the medial and lateral canthus was used as the horizontal reference point. Vertical lines perpendicular to the midpoint of the horizontal reference line were the vertical reference lines. The angles from the horizontal reference line to the lacrimal gland center and to the frontal tubercle were also measured. The length and thickness of the lacrimal gland were 12.8 and 2.4 mm, respectively. The lacrimal gland had an anterior protrusion of 4.1 mm from the superolateral orbital margin. The superior and inferior margins of the lacrimal gland were located 35.7° and 15.8° from the two reference lines, respectively. The angle from the horizontal reference line to the lacrimal gland center was 35.1°, which was similar to that to the frontal tubercle (34.4°). The orbital part of the lacrimal gland was more inferior in elderly subjects and the angle between the horizontal reference line and its center was 35.1°, which was similar to the location of the frontal tubercle. The location of this tubercle can help clinicians to perform BTX-A injections into the lacrimal gland, thereby enhancing the effectiveness of epiphora treatment.

The seminal vesicles are the glands of male reproductive organs that produce the fluid and nutrient constituents of semen. It has been believed for a long time that the lumen of a seminal vesicle was a single-coiled tubular structure with irregular diverticula. There are several previous reports on the symmetry, differences in morphological sizes and classification of the seminal vesicles. However, a three-dimensional-coiled tubular structure is difficult to understand using a classical anatomical methodology, and hence, three-dimensional reconstruction is needed to understand the structure of the lumen. Thirty-one seminal vesicles harvested from 21 formalin-embalmed cadavers were investigated. The seminal vesicle along with the ampulla of the ductus deferens was separated, and the length and width of each seminal vesicle were measured. The vesicles were then embedded in coloured paraffin, and the resulting paraffin block was sectioned transversely and photographed at an interval of 500 μm, with the sectioned surfaces then utilized in three-dimensional reconstruction performed by 'Reconstruct' software. The mean length and width of the seminal vesicles were 39.4 mm and 13.4 mm, respectively, and the right seminal vesicle was a little larger than the one on the left. The size differed from previous reports, while the luminal structure was similar to the classification of Aboul-azm (Archives of Andrology, 3, 1979, 287-292) but differed from that of Pereira (AJR. American Journal of Roentgenology, 69, 1953, 361-379). The seminal vesicles typically comprised about 9 curls and had about 12 diverticula. The seminal vesicles resembled a skein of coral rather than comprising a single strand. These findings will help in improving the understanding of pathophysiologies of the seminal vesicles, such as recurrent inflammation of the gland.

Summary Background The deep temporal fascia (DTF) is known to separate into two layers that descend to attach to the zygomatic arch. When surgeons reduce an isolated fracture of the zygomatic arch through a temporal approach, the temporal incision site needs to be superior to the split line of the DTF. Materials and Methods Sixty-seven hemifacial cadavers were investigated after removing the skin, subcutaneous tissue, and superficial temporal fascia. The superficial layer of the DTF was exposed. We cut the superficial layer along the line along, which it adhered to the deep layer inseparably. The heights of the split line of the DTF from the superior border of the zygomatic arch and from the top of the helix were measured at three points: at the jugale, zygion, and 3 cm from the tragus. Results In all cases there were thick identifiable deep layers of the DTF. The mean heights of the split line of the DTF from the superior border of the zygomatic arch were 49.8, 46.7, and 42.6 mm at the jugale, zygion, and 3 cm from the tragus, respectively; the corresponding mean heights of the split line from the top of the helix were 19.1, 15.6, and 11.4 mm. Conclusions Knowledge of the mean height of the split line of the DTF will be helpful for surgeons to determine the temporal incision site for ensuring the safe reduction of a zygomatic arch fracture.

Osteoporosis is a major disease in aged women, increasing the risk for fractures accompanied by changes in the microarchitecture. The aim of this study was to investigate the three-dimensional (3D) histomorphology of femur diaphysis in the animal model for postmenopausal osteoporosis. The cortical bone of femur diaphysis of the rat was serially sectioned at a thickness of 5 μm and evaluated age-associated changes of the intracortical (osteonal) canal networks three-dimensionally. Cortical microstructures of 10-month old rats were not affected by ovariectomy. Intracortical canal networks were radial toward endosteal aspect and frequently interconnected across the neighboring canals with short arciform and irregular canals reminiscent for resorption spaces in ovarectomized 16-month old rats, contrary to intact canals in 16-month old control rat. Increased proportion of the periosteal circumference lamella and deformed endosteal regions with rare cortical canals hampered reconstructive histomorphology in ovarectomized rats of 26 month age. We have shown that 3D reconstruction of rat femur of the aged model over 16-month old is suitable methods that evaluate and microstructural change of the intracortical canals and cortical bone porosity by estrogen depletion.

Frankfort horizontal line, the line passing through the orbitale and porion, is one of the most widely used intracranial landmarks in cephalometric analysis. This study investigated the use of the orbito-occipital line extending from the orbitale to the external occipital protuberance as a novel horizontal line of the skull for substituting the Frankfort horizontal line. We evaluated the reproducibility of the new landmark and measured the angle between the orbito-occipital line and the Frankfort line. This study was conducted on 170 facial computed tomography (CT) scans of living adults from the Department of Plastic Surgery. After three-dimensionally reconstructed images were obtained from facial CT, the porion, orbitale, and external occipital protuberance were indicated by two observers twice. The angles between the orbito-meatal line (inferior orbital rim to porion; the Frankfort line) and the orbito-occipital line (inferior orbital rim to external occipital protuberance) were measured. There was no significant intraobserver or interobserver bias. The overall angle between the Frankfort line and orbito-occipital line was −0.5°±2.2° (mean±standard deviation). There was no statistically significant difference among side and sex. This study demonstrated good reproducibility of a new landmark—the external occipital protuberance—tested to replace the porion. The orbito-occipital line is a reliable, reproducible, and easily identifiable line, and has potential as a novel standard horizontal line to replace or at least supplement the Frankfort line in anthropological studies and certain clinical applications.

Purpose: The intramuscular nerve distribution in the extraocular muscles is important for understanding their function. This study aimed to determine the intramuscular nerve distribution of...

Background Vision loss caused by retrograde occlusion of the central retinal artery is a serious complication of cosmetic filler injections. Salvage methods that involve applying hyaluronidases in the retrobulbar space to degrade filler materials have been proposed recently for rescuing the retinal circulation in an ophthalmic emergency. Methods Sixty-six eyeballs and orbital contents were extracted from formalin-embalmed cadavers and dissected carefully to examine the topographic relationship of the central retinal artery and optic nerve. To observe the three-dimensional course of a central retinal artery that invaginates into the optic nerve, serial sections reconstructed at 100-μm intervals using software were visualized in 11 specimens. Results The central retinal artery ramified from the ophthalmic artery and entered the optic nerve inferiorly at 8.7 ± 1.7 mm (mean ± SD) from the posterior margin of the eyeball. The intraneural course of a central retinal artery changed acutely between the periorbital environment of the fibrous optic nerve sheath, intermediate subarachnoid spaces, and center of the optic nerve stroma. Conclusion When applying a retrobulbar approach for central retinal artery reperfusion with hyaluronidases, the reliable access route is suggested to be at a depth of 3.0 to 3.5 cm from the border of the inferolateral orbital rim, based on consideration of the entry point of the central retinal artery into the optic nerve.

The present study is to identify primarily the morphological characteristics in the growth proportion of the head and face for young Korean (8~24 years) and compare the magnitude of growth changes to the sex-related differences. Total 1,255 were divided into 3 age groups: childhood (8~10 years), adolescence (14~16 years), and young adult (20~24 years). The anthropometric assessments were performed with 11 landmarks on the head and facial dimensions. The standardized frontal and lateral head and face photographs were analyzed the craniofacial growth proportions and morphological features for the comparison of both sexes. The noteworthy differences of anthropometric measurements between sexes with growing were noted on the lower head height (22.6%, 17.8%), midface height (22.0%, 19.6%), lower face height (23.5%, 14.7%), and face length (21.1%, 14.9%), face breadth (14.8%, 11.3%) of males and females, respectively. Whereas the upper head height (7.9%, 6.0%) and upper face height (4.2%, 0%, respectively) were less growing features. The most remarkable changes are the dimension of midface height and lower face height in both sexes. The present study could demonstrate a fundamental example to elucidate the sex-related dimensional differences for the analysis of the growth proportion of both sexes in Koreans.

The iliacus muscle is a large, flat, triangle-shaped muscle located in the iliac fossa. This muscle forms part of the iliopsoas muscle complex. Although anatomical variations of iliacus muscles are rare, some variations are clinically important due to the possible coexistence of an unusual course of the femoral nerve. The femoral nerve is the largest branch of the lumbar plexus and supplies the muscles and skin in the anterior aspect of the thigh. We encountered a case of a single aberrant slip of the iliacus muscle piercing the femoral nerve in the left iliac fossa of a male cadaver aged 97 years. The potential clinical importance of this variant iliacus muscle accompanied by a femoral nerve split would be femoral neuropathy and possible consequent alterations of sensation in the anterior and medial aspects of the thigh or motor deficit of the quadriceps muscle.

Vision loss and skin necrosis caused by an accidental intraarterial embolism or vascular compression are rare but devastating complications when injecting filler materials into the face.The external and internal diameters and wall thicknesses of the facial artery and its branches were measured from 41 formalin-embalmed cadavers after removing connective tissues attached to the arterial wall.The diameter and thickness of the facial artery exhibited significant interregional differences. The external and internal diameters of the facial artery were 1.9 ± 0.4 and 1.2 ± 0.3 mm (mean ± SD), respectively, at the inferior border of the mandible; 1.7 ± 0.3 and 1.2 ± 0.3 mm in the vicinity of the inferior labial artery; 1.5 ± 0.3 and 1.0 ± 0.3 mm at the mouth corner; 1.4 ± 0.3 and 0.9 ± 0.2 mm in the vicinity of the superior labial artery; and 1.1 ± 0.2 and 0.7 ± 0.2 mm in the vicinity of the lateral nasal artery. The external and internal diameters at the proximal parts of the inferior labial artery, superior labial artery, and lateral nasal artery were 1.0 ± 0.3 and 0.6 ± 0.2 mm, 0.9 ± 0.3 and 0.6 ± 0.2 mm, and 0.8 ± 0.2 and 0.5 ± 0.2 mm, respectively.Morphometric examinations of the facial artery under stereomicroscope observation as performed in the present study are expected to be more accurate than direct measurements obtained during cadaveric dissection or conventional histologic evaluations.

The intramuscular nerve distribution in the extraocular muscles may be crucial for understanding their physiological and pathological responses. This study aimed to determine the oculomotor nerve distribution in the medial rectus muscle (MR) using Sihler's staining.Thirty-seven MRs from 23 cadavers were investigated. The MR including the oculomotor nerve was finely dissected from its origin to its insertion point into the sclera. The total length of the muscle-belly, tendon length and maximum width of the muscle were measured. We evaluated the pattern of distribution and the length of the intramuscular nerve distribution by gross observation after performing Sihler's staining, which is a method for visualizing the distribution of nerve fibers without alteration of the nerve.The total length of the muscle-belly, tendon length, and muscle width were 37.6 ± 4.6 mm, 4.4 ± 1.9 mm, and 10 ± 1.8 mm, respectively. The oculomotor nerve enters the MR at a mean of two-fifths along the muscle (24 ± 2.0 mm posterior to the insertion point) and then typically divides into a few branches (mean of 2.1). The intramuscular nerve distribution showed a Y-shaped ramification, forming the terminal nerve plexus, and its course typically finished at around 17 ± 1.5 mm posterior to the muscle insertion point by gross observation. The nerve plexus in the upper part generally coursed more distally than the lower part.This new information regarding the nerve distribution pattern of MR will be helpful for understanding MR function and the diverse pathophysiology of strabismus.

The Frankfurt line is the most frequently and widely used reference line in cephalometric analysis, but has shortcomings including the difficulty of landmark identification. This study investigated using the superior border of the zygomatic arch as a new external bony landmark, including measuring the angle between the new reference line and the Frankfurt line. Facial computed tomography scans were obtained from 170 patients (100 males and 70 females) hospitalized at Konkuk University Chungju Hospital. After three-dimensional reconstruction, the locations of the porion and the inferior orbital rim and the superior border of the zygomatic arch were identified twice by two observers using software. A horizontal line parallel to the superior border of the zygomatic arch was established. The angle between the Frankfurt line and new reference line was then measured on each side. There was no significant intraobserver or interobserver bias. The angle between the Frankfurt line and the superior border of the zygomatic arch was 4.5° ± 2.5° (mean ± SD), and it was somewhat larger in females than males, but the difference was not statistically significant. This study demonstrated the good reproducibility of the location of the superior border of the zygomatic arch and found that the angle between the new reference line and the Frankfurt line is relatively constant. The superior border of the zygomatic arch therefore has potential as an alternative reference line to the Frankfurt line in specific clinical applications and anthropological studies, since it is a more accessible bony landmark on the external skull.

The corpus spongiosum reportedly occupies a larger proportion of the human glans penis than does the penile body, embedding the end of the corpus cavernosus (CC). However, anatomic descriptions about the fibrous structures of glans penis in the literature cause confusion during dissection and reconstructive surgery. Forty-five penises of formalin-embalmed cadavers were dissected sagittally along the course of the distal urethra and observed macroscopically. Dense connective tissues adjacent to the fossa navicularis and spongiosum parts of the glans were cropped, and underwent Masson's trichrome and Verhoeff-Van-Gieson staining. Most (55.5%) of the specimens had distinct fibrous bands toward the distal tips of the glans penis, which elongated from the tunica albuginea of the CC. They comprised longitudinal collagen bundles continuous to the outer longitudinal layer of the tunica albuginea covering the CC and were intermingled with sparse elastic fibres. This architecture either did not reach the distal end of the glans penis (35.5% of cases), or was obscure or dispersed in all directions (9.0% of cases). The structural dimorphism and the variations in the ratio of dense connective tissue components of the fibrous skeleton are considered to contribute to the varying degrees of flexibility, distensibility and rigidity of the human glans penis.

Summary Background Volumetric rejuvenation of the dorsum of the hand with fat grafting or injectable fillers has increased in popularity in recent years. It has become widely accepted that the dorsum of the hand contains three fatty laminae: superficial, intermediate, and deep laminae. The dorsal venous plexus and dorsal cutaneous nerves are known to reside in the dorsal intermediate lamina. However, the superficial vein and cutaneous nerve might not be located in the same layer of subcutaneous tissue, as is the case in other body regions. Materials and Methods Eight hands were dissected in a layer-by-layer fashion from the skin to the extensor tendons. In another 13 hands from among 21 investigated cadavers, samples from the dorsum of the hand were harvested and stained using trichrome stains for histologic analysis. B-mode ultrasound was also performed for identifying structures of the dorsum of the hand. Results Anatomic dissection and histologic analysis of the dorsum of the hand revealed the presence of an unknown fascia in addition to the three known fascial layers. The additional fascia was located in the dorsal intermediate lamina and separated it into two compartments: one containing the dorsal venous plexus superficially and the other containing the dorsal cutaneous nerves deeply. Ultrasound showed corresponding structures including three hyperechoic fascial layers, three hypoechoic laminae, and additional hyperechoic fascia in dorsal intermediate lamina. Conclusions Accurate anatomic knowledge of the dorsum of the hand will help practitioners determine the optimal and safe locations for performing fat grafting and injecting dermal fillers.

Knowledge of the distribution of intramuscular nerves of the extraocular muscles is crucial for understanding their function. The purpose of this study was to elucidate the intramuscular distribution of the oculomotor nerve within the inferior rectus muscle (IRM) using Sihler's staining.Ninety-three IRM from 50 formalin-embalmed cadavers were investigated. The IRM including its branches of the oculomotor nerve was finely dissected from its origin to the point where it inserted into the sclera. The intramuscular nerve course was investigated after performing Sihler's whole-mount nerve staining technique that stains the nerves while rendering other soft tissues either translucent or transparent.The oculomotor nerve enters the IRM around the distal one-fourth of the muscle and then divides into multiple smaller branches. The intramuscular nerve course finishes around the distal three-fifth of the IRM in gross observations. The types of branching patterns of the IRM could be divided into two subcategories based on whether or not topographic segregation was present: (1) no significant compartmental segregation (55.9% of cases) and (2) a several-zone pattern with possible segregation (44.1% of cases). Possible compartmentalization was less clear for the IRM, which contained overlapping mixed branches between different trunks.Sihler's staining is a useful technique for visualizing the gross nerve distribution of the IRM. The new information about the nerve distribution and morphological features provided by this study will improve the understanding of the biomechanics of the IRM, and could be useful for strabismus surgery.

This study aimed to elucidate the macroscopic and microscopic distributions of the dorsal nerve of penis (DNP) that provides the greatest sensitivity over the glans penis. The glandes of 23 penises of formalin-embalmed cadavers were investigated to confirm the macroscopic and microscopic distributions of the DNP within the glans penis by whole-mount Sihler's staining and histological sectioning. Superficial regions of the mid-glans were reconstructed in three dimensions to define the microstructure of terminal branches of the DNP that project towards the skin surface. A mean of 6.7 bundles of the DNP consisting of several nerve fibres converged linearly towards the distal end of the penis, rather than diverging laterally as they travelled. Lateral branches of the DNP extended linearly to the distal end with ramifications, while dorsomedial branches of the DNP gave off nerve fibres to the dorsum of the mid-glans and the corona. The intrastromal ramifications of the DNP were more developed in the distal half of the glans penis than the proximal glans containing the corpus cavernosum. These ramifications gave rise to radial nerve fibres that project towards the skin surface to form a plexiform network of terminal branches in the dermis. Linear projections of the main branches of the DNP throughout the glans and fine networks of terminal branches in the dermis were distinctly visualized in the human penis.

Background To help medical students learn anatomy effectively in limited hours, a regional anatomy book enhancing students' memorization was developed. Methods Only anatomical terms essential for basic cadaver dissection are included along with schematic figures which enable memorization of complicated anatomical structures. Learning comics and comic strips that depict anatomy mnemonics and jokes were appended and sentences were written to be comfortably readable. The electronic book titled “Visually Memorable Regional Anatomy” has been distributed without payment or registration. With the help of 246 volunteer students from three Korean medical schools, the book's learning effects were evaluated. Results These students' book reading led to increase in their anatomy scores, including written examination scores and tag examination scores. It was an encouraging result that almost 20% of students spontaneously read the book no matter who presented their lecture or examination. A webpage version of the book was visited by thousands of users. Conclusion The book with unique features may suggest a new perspective in the field of anatomy learning. After having acquaintance with essential structures from reading the book, students are able to and willing to study more from other resources., Graphical Abstract

Background Deep circumflex iliac artery osteocutaneous flap transfer has frequently been applied to large defects in the maxillary and mandible regions, but the use rate has decreased gradually because of the complicated anatomy of the deep circumflex iliac artery. This study investigated the comprehensive anatomy of the deep circumflex iliac artery in relation to flap surgery with the aim of providing navigational guidelines for safe deep circumflex iliac artery harvesting. Methods Sixty-two sides of the hemi-abdominal wall were dissected in fixed Korean cadavers. Several dimensions of the deep circumflex iliac artery and its positional relationships with surgical landmarks were measured, and the patterns of the arterial supply and anastomosis were identified. Results The mean distance between the anterior superior iliac spine and the lateral border of the femoral artery was 57.5 mm. The deep circumflex iliac artery generally originated almost at the same level as the inguinal ligament, and its highest level was 14.8 mm superior to that ligament. Emerging points of the ascending branch were observed both medial and lateral to the anterior superior iliac spine, but no transverse branch pierced the transversus abdominis muscle medial to the anterior superior iliac spine. Conclusions The incision line for safe deep circumflex iliac artery harvesting was parallel and 2 cm superior to the inguinal ligament and 6 cm from the anterior superior iliac spine. This position of the safe incision line can be easily determined using the thumb. Sex differences in the incidence of the deep circumflex iliac artery originating above or below the inguinal ligament will be another useful guide for easily detecting the deep circumflex iliac artery.

Objectives/hypothesis This study aimed to determine the prevalence and morphological variations of the oblique thyroarytenoid (TA) muscle in humans. Study design Cadaveric anatomic dissections. Methods One hundred hemilarynges from 50 formalin-embalmed cadavers were dissected to investigate the morphology of muscle fibers of the TA muscle. Results Thirty-six (36%) hemilarynges were found to have a distinct oblique belly superficial to the TA muscle. In 28 cases, the belly had a relatively constant origin and an insertion that extended straight onto the TA muscle from the anterosuperior area of the internal surface of the thyroid lamina to the base of the muscular process of the arytenoid cartilage. Eight cases were located in a similar area but with some differences in the origin or insertion features. Conclusions We proposed that the oblique TA muscle has a high prevalence and probably acts to close and relax the vocal cords. It remains to be determined whether the oblique TA muscle is an independent muscle or an accessory belly of the main TA muscle. Level of evidence NA. Laryngoscope, 128:1634-1638, 2018.

To investigate the topographical relationship between the frontal branch of the superficial temporal artery (FSTA) and the temporal branch of the facial nerve (TFN) with the aim of preventing nerve injury during FSTA biopsy. Fifty-seven hemifaces of 33 cadavers were dissected. Vertical lines drawn to the lateral orbital margin (LOM) and the superior root of the helix were used as the anterior and posterior reference positions, respectively. Horizontal lines drawn through the supraorbital margin and lateral canthus were used as the superior and inferior reference points, respectively. The depth and course relationships of the FSTA and TFN were examined. Midpoints between the FSTA and TFN are situated approximately 6.0 and 4.5 cm posterior to the lateral orbital margin at the levels of the lateral canthus and supraorbital margin, respectively. The TFN is generally situated 1-2 cm anteriorly and inferiorly to the FSTA in the temporal region. However, in two cases (3.6%), the TFN ran just underneath the FSTA with only a very small safe distance, making it highly vulnerable to iatrogenic injury. In conclusion, when performing an FSTA biopsy, the surgeon should not dissect below the superficial temporal fascia because there is an overlap between the course of the FSTA and the TFN in a minority of cases. Also, surgical incisions should be made outside the area delineated by an oblique line passing through the points 6.0 and 4.5 cm posterior to the lateral orbital margin at the levels of the lateral canthus and the supraorbital margin, respectively. Clin. Anat. 31:608-613, 2018. © 2017 Wiley Periodicals, Inc.

Posterior projections of the ophthalmic division of the trigeminal nerve (the ophthalmic nerve) are distributed in the tentorium cerebelli as recurrent meningeal branches. We investigated the morphological tentorial distribution of the ophthalmic nerve. Fifty-two sides of the tentorium cerebelli and adjacent dura mater obtained from 29 human specimens were stained using Sihler's method to examine the nerve fibres in the dural sheets. The innervation patterns of the tentorium cerebelli were classified into the following four types according to their distributions: Type 1, where nerve fibres projected to both the straight and transverse sinuses; Type 2, where nerve fibres projected only to the transverse sinus and lateral convexity; Type 3, where nerve fibres projected medially only to the straight sinus and the posterior part of the falx cerebri; and Type 4, where the nerve fibres terminated within the tentorium cerebelli. Images of the tentorium cerebelli were superimposed to identify areas of dense innervation. The incidence rates of Types 1-4 were 71.2% (n = 37), 21.2% (n = 11), 3.8% (n = 2) and 3.8% (n = 2), respectively. More branches of nerve fibres traversed towards the transverse sinus posterolaterally than towards the straight sinus medially. The space between the anterior half of the straight sinus and the medial tentorial notch can be considered a safe surgical area where innervation is scarce. The posterior part of the falx cerebri was innervated by the ophthalmic nerve that traversed to the straight sinus. The parietal branches of the middle meningeal artery in the lateral convexity that were projected orthogonally by the ophthalmic nerve traversed the transverse sinus, implicating their vulnerability and possible sensitivity under physiological or neurosurgical conditions. This study has revealed the macroscopic tentorial innervation of the dura mater in humans, which could be useful information for both neurosurgeons and neurologists.

Introduction: Compression of the lateral femoral cutaneous nerve (LFCN), known as meralgia paresthetica (MP), is common. We investigated the topographic anatomy of the LFCN focusing on the inguinal ligament and adjacent structures. Methods: Distances from various bony and soft-tissue landmarks to the LFCN were investigated in 33 formalin-embalmed cadavers. Results: The mean distance from the anterior superior iliac spine (ASIS) to the LFCN was 8.8 mm. In approximately 90% of cases, the LFCN lay

Purpose To elucidate the course of the supraorbital nerve (SON) with reference to the lacrimal caruncle in order to facilitate safer direct browplasty by preventing nerve injury. Methods Thirty-four hemifaces from 18 embalmed Korean cadavers were dissected. A vertical line through the upmost point of the lacrimal caruncle and a horizontal line through the supraorbital margin were used as the horizontal and vertical reference positions, respectively. The course of the SON in the frontal view and the point at which it pierced the overlaying musculature were examined. Results The SON divides into a superficial branch and a deep branch just after exiting the orbit. In all cases, the deep SON remains in the subgaleal plane deep to the corrugator and frontalis muscles. The superficial SON travels under the corrugator muscle dividing into three branches (medial, intermediate and lateral) and pierced the frontalis muscle at 19–32 mm above the supraorbital margin. However, in 11 cases (32%) the medial branch of the superficial SON pierced the lower portion of the corrugator muscle at 3.6 mm above the supraorbital margin and ran in front of the muscle along with the vertical line through the upmost point of the lacrimal caruncle. Conclusions One-third of the medial branch of the superficial SON without corrugator muscle protection is vulnerable to iatrogenic injury during direct browplasty. Therefore, the oculofacial surgeon must bring the dissection plane of the forehead tissue more superficially around the vertical line through the upmost point of the lacrimal caruncle in order to avoid nerve injury.

PURPOSE The aim of the study was to elucidate the positional relationship of the ethmoidal foramens (EFs) with reference to the nasion to facilitate prediction of the exact location of EFs, the optic canal (OC), and the frontoethmoidal suture (FS), and thereby avoid complications during complex surgery involving the medial wall of the orbit. MATERIALS AND METHODS One hundred two intact orbits of 57 embalmed cadavers were dissected in this observational anatomic study. Nasion' (N') was defined as the intersection point of the medial orbit margin with the horizontal line through the nasion, and this was used as a reference point. N'-OC was defined as the straight line joining N' and OC. The locations of the anterior ethmoidal foramen (AEF), posterior ethmoidal foramen (PEF), and OC were determined with reference to N'. The vertical distances from N'-OC to EFs and to FS were also determined. RESULTS The N'-AEF, AEF-PEF, and PEF-OC distances were 18.4, 15.3, and 8.3 mm, respectively. Vertically, AEF and PEF were situated at 0.2 mm below and 0.4 mm above N'-OC, respectively. At the same reference points, N'-OC was situated at 0.4 and 0.6 mm above FS, respectively. CONCLUSIONS N', AEF, PEF, and OC were considered to be situated on the same straight line, and N'-OC could be regarded as coinciding with FS. This means that N' is an easily identifiable and reliable landmark for identifying EFs, OC, and FS. Our navigational parameters with reference to N' will help surgeons to enhance the safety of orbital surgery.

The aim of this study was to identify the three-dimensional topography of the sphenoid door jamb (SDJ) in the lateral orbital wall and to propose navigational guidelines for safe deep lateral decompression using surgical landmarks. The 120 orbits and SDJs of 60 subjects were three-dimensionally reconstructed using Mimics software. The mean volumes of the orbit and SDJ were 24.3 mm3 and 2.0 mm3, respectively. The mean distances from the lateral orbital margin (LOM) to the anterior and posterior margins of the SDJ were 13.2 and 36.3 mm, respectively. The mean distances from the superior orbital fissure to the LOM and to the posterior margin of the SDJ were 40.2 mm and 4.6 mm, respectively. The mean distances from the inferior orbital fissure (IOF) to the anterior and posterior margins of the SDJ were 3.8 mm and 20.5 mm, respectively. In the superior approach of the orbit, it can be predicted that the area up to 3 cm posterior from the LOM is safe, while 1 cm posterior from the safe zone could be a dangerous zone. In the inferior approach of the orbit, the safe area will be about 1 cm posterior from the anterior tip of the IOF, and the area up to 1 cm posterior from the safe zone should be approached with extreme care.

Successful oculofacial procedures require the availability of a reliable surgical and anatomic landmark. This study aimed to determine the usefulness of the lateral canthus as a surface landmark. Seventy-seven from 42 Korean cadavers were dissected. The horizontal distance from the lateral canthus to the lateral orbital margin and the vertical distances from the zygomaticofrontal suture and the inferior orbital margin to the lateral canthus were measured. The mean horizontal distance from the lateral canthus to the lateral orbital margin was 7.8 mm. Although the horizontal position of the lateral canthus appears to alter with age, the variation was only 2-3 mm. The mean vertical distances from the zygomaticofrontal suture and inferior orbital margin to the lateral canthus were 8.1 and 17.2 mm. The vertical position of the lateral canthus did not vary with age, being located inferiorly within a fingernail width from the zygomaticofrontal suture. The lateral canthus, which is easily accessible and supported by muscular and fibrous lateral orbital attachments, exhibits small anatomic variations. Thus, the lateral canthus could act as a reliable surface landmark for identifying the location of underlying structures and describing a lesion on the face. Clin. Anat. 32:630-634, 2019. © 2019 Wiley Periodicals, Inc.

PURPOSE This study evaluated midfacial asymmetry using an alternative method that involved comparing bilateral patterns of the zygomaticomaxillary prominence in a young adult population. MATERIALS AND METHODS Three-dimensional reconstructed images based on computed tomography scans of 100 Koreans (mean age, 24.7 years) were evaluated with reference to lines spaced at 30° intervals and radiating from the center of an interporion line in a superior view. The surface inclination of the zygomaticomaxillary region was quantified on the same reference lines using a 3-dimensional ruler. RESULTS The 30°-interval line (at the level of the zygomaticotemporal suture) was longer on the left side than the right side in both males and females, whereas the left 60°-interval line (at the level of the zygomaticofrontal suture) was longer in females. Comparing the surface protrusion revealed that the zygomaticomaxillary region was more prognathic and inflated on the left side. CONCLUSION Functional deviations are considered to be causes of asymmetric craniofacial growth. Postnatal growth allometry across the circummaxillary sutures as elucidated by this study could be useful information in craniofacial surgery.

Background Blocking the supraorbital nerve (SON) and supratrochlear nerve (STN) by injecting anesthetic distal to the surgical site has the advantage in upper eyelid surgery that avoids obscuring the surgical landmarks and compromising the levator function. Objective To identify the emerging points of the SON and STN in the supraorbital margin with reference to the lacrimal caruncle. Methods Forty-nine orbits from 27 embalmed Korean cadavers were dissected. The lacrimal caruncle and facial midline were used as landmarks. The emerging points of the SON and STN in the supraorbital margin were determined. Results The emerging points of the SON and STN were, respectively, located at 3.0 mm lateral and 3.3 mm medial to the vertical line through the apex of the lacrimal caruncle along the supraorbital margin. The horizontal distances from the facial midline to the emerging points of the SON and STN were 22.8 and 15.2 mm, respectively. Conclusion The optimum sites for achieving SON and STN block are, respectively, located approximately 3 mm lateral and 3 mm medial to the vertical line through the apex of lacrimal caruncle along the supraorbital margin. This knowledge will help the surgeon achieve an easy and accurate approach for regional nerve block.

To provide anatomical and morphological data regarding the coccyx using three-dimensional images, with a view to aiding the diagnosis of idiopathic coccydynia, one hundred and thirty-six normal adult pelvises were investigated. Three-dimensional models of the pelvis were reconstructed using software from computed tomography images of whole specimens. The following six coccyx parameters were measured: (1) width, (2) straight length, (3) thickness, (4) sacrococcygeal angle, (5) intercoccygeal angle, and (6) angle of lateral deviation of the coccyx. The presence of fusion between the sacral and coccygeal cornua, and between the sacrum and the transverse process of the coccyx was also investigated, and lateral deviations of the coccyx were classified and analyzed. Most of the measured coccyx parameters were larger in males than in females, with the exception of the sacrococcygeal and intercoccygeal angles. Unilateral or bilateral fusion of the sacral cornu and the coccygeal cornu was not a rare finding. With respect to the sacrum and the transverse process of coccyx, the separated type was more common than the fused type. The incidence and angle of lateral deviation of the coccyx varied widely between individuals. The present detailed description of the gross anatomy of the coccyx obtained using three-dimensional modeling will help toward understanding the mechanism underlying the development of idiopathic coccydynia. Fusion of the sacrum and coccyx or lateral deviation of the coccyx may cause coccydynia by compressing the coccygeal nerves.

Despite some progress performed, state-of-the-art lithium ion batteries still require improvements in energy and power to extend the range of electric vehicles and reduce charging time. In this domain, all-solid-state batteries are viable alternatives to conventional batteries employing organic electrolytes because of their benefits, i.e., high power density, high energy density, long-life operation and safety. These advantages stem from the great features of inorganic solid electrolytes, which are single ion conductor, so a high lithium ion transport number, and no-liquid nature. In particular, the sulfide-based solid electrolytes possess favorable mechanical properties, allowing all-solid-state batteries to be easily prepared via simple mixing and cold-pressing processes, facilitating the scale-up. Sulfide-based solid-electrolytes can potentially be employed in conjunction with a lithium metal negative electrode and 5V-class high voltage positive electrode material. Indeed, lithium metal is believed to be the most promising negative electrode due to its specific large capacity (3862 mAh.g-1), low volumetric density (0.534 g.cm-3 at 20°C) and the lowest electrochemical potential (-3.03V vs ENH). Nevertheless, like most metal, lithium metal is morphologically dynamic. Its surface morphology is modified, since during the electrochemical cycling, a part of lithium migrates to the other electrode to react and is then plating on its surface heterogeneously, leading to a volume change and sometimes dendrite growth with potential internal short circuit and life-threatening accidents. Ceramic solid electrolytes have been considered to be the ideal solution to prevent dendrite growth because of their high shear modulus and high lithium transference number. In the same time, the chemical nature and composition of ceramic solid electrolyte can affect the dendrite growth by the interfacial chemical and electrochemical stability with lithium metal forming solid electrolyte interphase as a passivating layer. Since the lithium dendrites have to grow through this layer, its composition should play an important role in the dendrite formation. Moreover, it is known that the stack can be easily deformed because lithium dendrite growth with a high shear modulus, indicating that the solid electrolyte and its interface with lithium metal should be sufficiently strong to endure the pressure originating from lithium dendrite growth. The oxide–based ceramic solid electrolytes can be shaped by sintering at high temperature, leading to a grain and grain-boundary microstructure with some porosity, facilitating the lithium dendrite growth through grain boundaries. Due to the low density and plasticity of sulfide based inorganic solid electrolyte, the dendrite growth through the particle-particle contact can be reduced but still present. Different parameters can influence the lithium dendrite growth and the critical current density in ceramic all-solid-state configuration, such as the solid electrolyte chemical composition, particle size, and the compactness of ceramic solid electrolyte. The pressure effect on the electrochemical performances of sulfide electrolytes was investigated. The pressure affects resistive grain boundaries, contact between lithium metal and solid electrolyte and lithium plating. As, the kinetics of reaction is derived from thermodynamic parameters, the temperature can affect the plating/stripping phenomena. These different parameters and the relationship between them will be presented and explained through complete studies based on sulfide solid electrolytes with the combination of various chemical and electrochemical techniques.

To elucidate the intramuscular distribution and branching patterns of the abducens nerve in the lateral rectus (LR) muscle so as to provide anatomical confirmation of the presence of compartmentalization, including for use in clinical applications such as botulinum toxin injections.Thirty whole-mount human cadaver specimens were dissected and then Sihler's stain was applied. The basic dimensions of the LR and its intramuscular nerve distribution were investigated. The distances from the muscle insertion to the point at which the abducens nerve enters the LR and to the terminal nerve plexus were also measured.The LR was 46.0 mm long. The abducens nerve enters the muscle on the posterior one-third of the LR and then typically divides into a few branches (average of 1.8). This supports a segregated abducens nerve selectively innervating compartments of the LR. The intramuscular nerve distribution showed a Y-shaped ramification with root-like arborization. The intramuscular nerve course finished around the middle of the LR (24.8 mm posterior to the insertion point) to form the terminal nerve plexus. This region should be considered the optimal target site for botulinum toxin injections. We have also identified the presence of an overlapping zone and communicating nerve branches between the neighboring LR compartments.Sihler's staining is a useful technique for visualizing the entire nerve network of the LR. Improving the knowledge of the nerve distribution patterns is important not only for researchers but also clinicians to understand the functions of the LR and the diverse pathophysiology of strabismus.

The trigeminovascular system within the cranial dura mater is a possible cause of headaches. The aim of this study is to investigate macroscopically dural innervation around the middle meningeal artery (MMA) in the middle cranial fossa. Forty-four sides of the cranial dura overlying the skull base obtained from 24 human cadavers were stained using Sihler’s method. Overall, the nervus spinosus (NS) from either the maxillary or mandibular trigeminal divisions ran along the lateral wall of the middle meningeal vein rather than that of the MMA. Distinct bundles of the NS running along the course of the frontal branches of the MMA were present in 81.8% of cases (N = 36). Others did not form dominant nerve bundles, instead giving off free nerve endings along the course of the MMA or dural connective tissue. The distribution of these nerve endings was similar to that of the course of the frontal, parietal and petrosal branches of the MMA (11.4%). The others were not restricted to a perivascular plexus, crossing the dural connective tissues far from the MMA (6.8%). These findings indicate that the NS generally travels alongside the course of the frontal branches of the MMA and terminates in the vicinity of the pterion.

Purpose To identify the location of the inferior oblique muscle (IOM) origin with reference to the lacrimal caruncle in order to facilitate safer oculofacial surgery by preventing morbidity associated with IOM injury. Methods Thirty-seven intact orbits of 20 embalmed Asian cadavers were dissected. The location of the medial border of the IOM origin was determined with respect to the apex of the lacrimal caruncle. In addition, the size of the IOM origin and the anteroposterior distance from the inferior orbital rim to the anterior border of the IOM origin were measured. Results The IOM origin was located at a mean distance of 1.2 mm lateral and 11.2 mm inferior to the apex of the lacrimal caruncle. In half of the orbits, the IOM origin was situated just on the vertical line through the apex of the lacrimal caruncle. The mean length and width of the IOM origin were 4.3 and 2.7 mm, respectively. The mean anteroposterior distance from the inferior orbital rim to the IOM origin was 1.9 mm. Conclusions The lacrimal caruncle is easily identifiable and a reliable external landmark for prediction of the IOM origin. The IOM origin is located approximately where the vertical line through the apex of the lacrimal caruncle intersects the inferior orbital rim. The findings of this anatomical study of the exact location of the IOM origin can help to improve the safety of oculofacial surgery.

The aim of this study was to clarify the definition of the anterior wall of the ulnar tunnel and to reveal the topographical characteristics of the various components of the ulnar tunnel.Twenty-two forearms from 11 embalmed cadavers (7 males, 4 females; mean age, 67.8 years) were carefully dissected.In all cases, the anterior wall of the ulnar tunnel comprised the hypothenar fascia, which originated from the tendon of the flexor carpi ulnaris muscle. The palmar carpal ligament, the distal extent of the antebrachial fascia, was located deep to the anterior wall and formed only the anterior boundary of the proximal hiatus of the ulnar tunnel. The hypothenar fascia was attached to the flexor retinaculum at 15.2 mm lateral to the pisiform bone. However, the palmar carpal ligament was attached to the flexor retinaculum just lateral to the ulnar artery; the distance between the attachment of the palmar carpal ligament and the pisiform bone was 8.7 mm. Anatomical variations potentially associated with ulnar nerve compression were observed. The accessory abductor digiti minimi muscle and the fibrous band crossing the ulnar nerve in the ulnar tunnel were found in 27 and 23 % of forearms, respectively.A more detailed description of the anterior wall of the ulnar tunnel than was previously available is presented herein, and topographic and metric data regarding each structure of the tunnel are reported.

Background The aims of the present study were to clarify the topographic relationships between various structures in the lateral midface and to provide important anatomical information pertinent to face lifting or treatment of damage to the midface structure. Methods Thirty-two fixed cadavers were dissected (23 males and 9 females; mean age, 66.8 years) and 55 sides of midface were used. The transverse facial artery (TFA), zygomatic branch (Zb) and buccal branch (Bb) of the facial nerve, and the parotid duct (PD) were identified. The structures of the lateral midface were measured relative to the zygion and tragion. The vertical average distances from the zygion to each structure increased in the following order: ZB of the facial nerve, TFA, first Bb of the facial nerve, and PD. The horizontal average distance from the tragion to the point of emergence from anterior border of the parotid gland was also measured. Results The TFA was the closest and the third Bb of the facial nerve was the farthest away. The angles between the horizontal line and ZB of the facial nerve, TFA, PD, and first Bb of the facial nerve were +10.4, -2.3, -18.5, and -27.1 degrees, respectively. Conclusions These results may be used to establish the precise locations and the courses of the important midface structures, and represent valuable data that may help to prevent complications during surgery for face lifting and reconstruction of the facial nerve and PD.

The aims of this study were to determine the various dimensions of the normal facial canal and to identify the spatial relationships between the facial canal and its adjacent structures using microcomputed tomography (micro-CT) imaging and three-dimensional (3D) reconstruction. The petrous parts of 54 temporal bones were scanned using micro-CT with a slice thickness of 35 μm. The serial micro-CT images were used to reconstruct 3D volumes of the facial canal and the bony labyrinth with the aid of computer software. These volumes were used to measure 31 dimensions of the facial canal and its spatial relationships with adjacent structures. The length of the meatal segment, the tympanic segment, and the mastoid segment were significantly larger in males than in females (p 180°. These findings represent supplemental data for improving the detailed understanding of the facial canal anatomy. Anat Rec, 297:1808–1816, 2014. © 2014 Wiley Periodicals, Inc.

BACKGROUNDS The aims of the present study were to determine the exact level of separation of the upper lateral cartilage from the septal cartilage, and to classify the patterns of connection between the upper lateral cartilage and the lower lateral cartilage. METHODS We dissected and photographed 60 sides of noses; 18 specimens were sectioned and stained with Masson's trichrome. RESULTS The mean length of the connection between the upper lateral cartilage and septal cartilage was 16.1 mm. The mean level for separation of the upper lateral cartilage was 7.5 mm from the nasal bone. The pattern of connection between the upper lateral cartilage and lower lateral cartilage could be classified into five types: disconnection, end-to-end, overlap, scroll, and reverse scroll. CONCLUSIONS The results of the present study will be helpful for surgical procedures such as nasal hump reduction and nasal cartilage work and also provide information for the anthropometric study of the nose.

Summary Background Androgenetic (male-type) alopecia (AGA) is caused by genetic and androgenetic effects. The progression of baldness results in smaller hair papillae, thinner hair and a shortened hair cycle. Alopecia occurs mainly in the frontal region and, to a lesser extent, in the occipital region. Objectives The morphological differences in the hair follicular units between the alopecic frontal scalp and the vertex and occipital regions were compared using cross-sectional histology and three-dimensional reconstruction. Methods Skin specimens were obtained from the frontal, vertex and occipital regions of 24 male human cadavers with fully progressed AGA, and from the frontal region of 32 normal cadaveric scalps. These specimens were fixed, processed using routine histological methods, serially sectioned at a thickness of 10 μm and then stained with Masson's trichrome. The serial sections were reconstructed three-dimensionally using ‘Reconstruct’ software. Results The ratios between the numbers of terminal and vellus hairs in the frontal and occipital regions in the AGA scalps were 0·2 : 1 and 3·5 : 1, respectively. Almost all of the hair follicles in the frontal region were vellus hair follicles. The sebaceous gland and arrector pili muscle were larger in the frontal region than in the occipital region. Conclusions The morphology of the AGA scalp has been characterized. The terminal-to-vellus hair ratio in the occipital (normal) region was different from that in the frontal (alopecic) region. Moreover, sebaceous glands were larger in the frontal alopecic region than in the occipital region. These larger glands may be associated with other dermatological pathologies, such as seborrhoeic dermatitis.

This study investigated the cycle of rat vibrissae by counting their number relative to their topographic arrangement. The average duration of maintaining single or double vibrissal shafts was analyzed. The ratio of the lifetime of the single and double shafts was around 3:2 weeks. The rostral and caudal vibrissae had relatively short and long cyclic durations, respectively; this difference may be related to their length and function.

The aim of this study was to provide data on various dimensions of the normal cochlea using three-dimensional reconstruction based on high-resolution micro-CT images. The petrous parts of 39 temporal bones were scanned by micro-computed tomography (CT) with a slice thickness of 35 μm. The micro-CT images were used in reconstructing three-dimensional volumes of the bony labyrinth using computer software. The volumes were used to measure 12 dimensions of the cochlea, and statistical analysis was carried out. The dimensions of cochleae varied widely between different specimens. The mean height and length of the cochlea were 3.8 and 9.7 mm, respectively. The angle between the basal and middle turns was slightly larger in males than in females, while none of the other 11 dimensions differed significantly between males and females. The cochlear accessory canals were observed in about half of the cases (51.3%). Correlation analysis among measured items revealed positive correlations among several of the measured dimensions. The present study could investigate the detailed anatomy of the normal cochlea using high-resolution imaging technologies. The results of the present study could be helpful for the precise diagnosis of congenital cochlear malformations and for producing optimized cochlear implants.

It is generally accepted that the three semicircular canals are set at right angles to each other and the lateral semicircular canal is smaller than the anterior and posterior semicircular canals. Precise knowledge of the size and spatial relationships of the semicircular canals is vital, and so the 40 petrous parts of the temporal bones were scanned by micro-CT at a slice thickness of 35 µm. The micro-CT images were used in reconstructing three-dimensional models of the bony labyrinth using computer software. Various dimensions of the semicircular canals were measured using the software, and statistical analysis was performed. The anterior semicircular canal was slightly wider than the posterior semicircular canal, and their heights were similar. The radius of curvature of the lateral semicircular canal was 20% smaller than those of the anterior and posterior semicircular canals. The angles between the three canals were not exactly 90 degrees: they were 92.1, 84.4, and 86.2 degrees between the anterior and posterior, anterior and lateral, and posterior and lateral semicircular canals, respectively. We obtained high-resolution images of the semicircular canals using three-dimensional reconstruction software, and these were used to precisely measure the angles between the semicircular canals and the area of the distorted circle formed by each semicircular canal.

Compression of the lateral femoral cutaneous nerve (LFCN), known as meralgia paresthetica (MP), is common. We investigated the topographic anatomy of the LFCN focusing on the inguinal ligament and adjacent structures.Distances from various bony and soft-tissue landmarks to the LFCN were investigated in 33 formalin-embalmed cadavers.The mean distance from the anterior superior iliac spine (ASIS) to the LFCN was 8.8 mm. In approximately 90% of cases, the LFCN lay2 cm from the medial tip of the ASIS, whereas, in 76% of cases, it was1 cm away. The mean angle between the inguinal ligament and LFCN was 83.3°.We determined the variability of the location of the LFCN at the boundary between the pelvic and femoral portions. The reported results will be helpful for diagnosis and treatment of MP. Muscle Nerve 55: 646-650, 2017.

The aim of the present study was to assess normal eyeball protrusion from the orbital rim using two- and three-dimensional images and demonstrate the better suitability of CT images for assessment of exophthalmos.The facial computed tomographic (CT) images of Korean adults were acquired in sagittal and transverse views. The CT images were used in reconstructing three-dimensional volume of faces using computer software. The protrusion distances from orbital rims and the diameters of eyeballs were measured in the two views of the CT image and three-dimensional volume of the face. Relative exophthalmometry was calculated by the difference in protrusion distance between the right and left sides.The eyeball protrusion was 4.9 and 12.5 mm in sagittal and transverse views, respectively. The protrusion distances were 2.9 mm in the three-dimensional volume of face. There were no significant differences between right and left sides in the degree of protrusion, and the difference was within 2 mm in more than 90% of the subjects.The results of the present study will provide reliable criteria for precise diagnosis and postoperative monitoring using CT imaging of diseases such as thyroid-associated ophthalmopathy and orbital tumors.