Statistical classification methods for estimating sex based on five skull traits: A nonmetric assessment using 3D CT models.

Five cranial nonmetric traits for sex estimation for sex estimation are classified by score according to geometry. The population of origin is one of the factors influencing cranial nonmetric traits. Moreover, among the five cranial traits, the robust traits for estimating sex varied across population. The aim of this study is to suggest the most useful method for sex estimation and demonstrate the need of a suitable method for each population. One-hundred thirty-five three-dimensional skull images from 21st century Korean autopsy cadavers were evaluated using the ordinal scoring system of five cranial nonmetric traits as outlined in Buikstra & Ubelaker (1994). All scores of each trait were analyzed by linear discriminant and decision tree analyses for sex estimation. The frequency of each trait was analyzed and compared to populations from other studies. The accuracy for both sexes was 88.1% by discriminant analysis and 90.4% by decision tree. The traits with the highest accuracy were the glabella and mastoid process in both discriminant analysis and decision tree. Sex estimation in modern Korean cadavers using the cranial nonmetric method was shown to be highly accurate by both discriminant analysis and decision tree. When comparing the pattern of frequency scores in this study with those of other populations, the pattern of trait scores for estimating sex was different for each population, even among populations in the same Asian region, which suggests the need for methods suited for specific populations.

Evaluating the effectiveness of gluteal intramuscular injection sites: a cadaveric study.

The gluteal region is a frequent target for injecting high volumes. However, the safe intramuscular injection sites have been controversy in this region. This study was aimed to compare the subcutaneous fat and muscle thicknesses at the two gluteal injection sites and to determine the influence of sex and body mass index (BMI) on fat and muscle thicknesses. The ultimate purpose of this study is to suggest the most suitable intramuscular injection site among the ventrogluteal and dorsogluteal regions. Eleven fresh cadavers were injected with colored gelatin using syringes at the two gluteal injection sites. Seven variables were measured at both gluteal injection sites and analyzed relative to sex and the BMI. No variables showed statistically significant differences between the two gluteal injection sites according to sex. In a one-way analysis of variance, total length and muscle thickness had significant difference according to the BMI category. In obese cadavers, the injected gelatin core was located in the subcutaneous layer (average 109.0 percentile), and in the muscle layer (average 78.9 percentile) in the dorsogluteal region. These were found that the success rate of injection in the dorsogluteal region was higher than in the ventrogluteal region, especially when classed as obese. Also, it is suggested that nurses should use the traditional intramuscular injection method. It will also be necessary to consider expanding these findings to other ethnic groups in the Asia-Pacific region and then also education in universities and health providers on selecting the intramuscular gluteal injection site.

A rare branching pattern of hindgut: absence of inferior mesenteric artery.

The arterial system of the gastrointestinal tract has many variations. However, variation in the inferior mesenteric artery (IMA) is less common than for the other abdominal arteries. The case in the present cadaver subject showed a variation in the anatomy of the IMA that differed from those seen in previous studies, because it did not originate from the abdominal aorta and had no branches. A single artery arising from branches of the inferior pancreaticoduodenal and middle colic arteries supplied the hindgut. This variation generated blood vessels along the digestive tract during the later stages of development. The marginal artery of the colon in this case probably was more highly developed instead of the IMA. It is clinically important to know the range of variations, as these data are used in the diagnosis and treatment of abdominal diseases. This hitherto unknown variation might affect the health of patients, and we recommend radiographic examinations for diagnosis and treatment.

Topography of human ankle joint: focused on posterior tibial artery and tibial nerve.

Most of foot pain occurs by the entrapment of the tibial nerve and its branches. Some studies have reported the location of the tibial nerve; however, textbooks and researches have not described the posterior tibial artery and the relationship between the tibal nerve and the posterior tibial artery in detail. The purpose of this study was to analyze the location of neurovascular structures and bifurcations of the nerve and artery in the ankle region based on the anatomical landmarks. Ninety feet of embalmed human cadavers were examined. All measurements were evaluated based on a reference line. Neurovascular structures were classified based on the relationship between the tibial nerve and the posterior tibial artery. The bifurcation of arteries and nerves were expressed by X- and Y-coordinates. Based on the reference line, 9 measurements were examined. The most common type I (55.6%), was the posterior tibial artery located medial to the tibial nerve. Neurovascular structures were located less than 50% of the distance between M and C from M at the reference line. The bifurcation of the posterior tibial artery was 41% in X-coordinate, -38% in Y-coordinate, and that of the tibial nerve was 48%, and -10%, respectively. Thirteen measurements and classification showed statistically significant differences between both sexes (P<0.05). It is determined the average position of neurovascular structures in the human ankle region and recorded the differences between the sexes and amongst the populations. These results would be helpful for the diagnosis and treatment of foot pain.

Neurovascular distribution within the abdominal head of the pectoralis major muscle: Application to breast and flap surgery.

The abdominal head of the pectoralis major (AHPM) is important in cosmetic and flap surgeries. Few studies have reported on its neurovascular entry points and distribution patterns. We aimed to determine the entry points and distribution patterns of the neurovascular structures within the AHPM. Thirty-two hemithoraxes were dissected, and the distribution patterns of the neurovascular structures were classified into several categories. The neurovascular entry points were measured at the horizontal line passing through the jugular notch (x-axis) and the midclavicular line (y-axis). The AHPM was innervated by the communication branches of the medial pectoral nerve (MPN) and the lateral pectoral nerve (LPN) in 78.1% of the specimens and of the MPN without the communication branches in 21.9%. All the LPNs had communication branches, which could be classified as independent in 46.9% of the samples, with the MPN in 21.9%, and with the LPN in 9.3%. The blood supply of the AHPM was composed of branches from the lateral thoracic artery (LTA) in 62.5% of the specimens, the thoracoacromial artery (TA) in 15.6%, and the LTA with the TA in 21.9%. The mean distance of the entry point was 6.3 cm ± 1.3 cm lateral to the y-axis, 8.1 cm ± 3.3 cm below the x-axis in the nerves, 6.5 cm ± 1.2 cm lateral to the y-axis, and 8.6 cm ± 3.0 cm below the x-axis in the arteries. This study defined the average neurovascular entry point and distribution pattern in detail using standard lines to enable the AHPM to be better understood.

Sex determination using discriminant analysis of the medial and lateral condyles of the femur in Koreans.

The proximal and distal parts of the femur show the differences between the sexes. Head diameter and the breadth of the epicondyle of the femur are known to distinguish males from females. The proximal end of the femur is studied to determine sex using discriminant analysis but; its distal end is not done. This study aims to develop an equation specific to Koreans by using the medial and lateral condyles of the femur, and to demonstrate the usefulness of equations for specific population groups. We used three-dimensional images from 202 Korean femurs. Twelve variables were measured with a computer program after the femurs were in alignment. Eleven variables showed a statistically significant difference between the sexes (P<0.01). The most accurate equation used width of the medial and lateral condyles (WDC), with of the medial condyle (WMC), depth of the lateral condyle (DLC), and depth of the intercondylar notch (DIN) (94.1%), and is as follows: D = 0.336 × WDC + (-0.097) × WMC + (-0.153) × DLC + 0.372 × DIN - 20.912. The second highest accuracy was 90.1% for the width dimensional group and WDC. This study shows that the medial and lateral condyles of the femur should be helpful for sex determination in situations where the skull and pelvis are missing and part of the femur is available. The study also demonstrates the need for different equations for different population groups.

Sex determination from calcaneus in Korean using discriminant analysis.

The calcaneus can be used for the differentiation of sex and populations using discriminant function equations. This bone has been used for sex determination in some population groups, but it has not been used for sex determination in Koreans until now. The purpose of this study was to develop discriminant function equations for sex determination from the calcaneus in modern Koreans and prove the need for population-specific discriminant function equations. The sample consisted of 104 calcanei from modern Korean cadavers, and 10 variables were measured for each. All variables showed statistically significant sexual differences (P<0.05) and generated a large effect size (Cohen's d>0.9). The accuracy ranged from 65.4 to 89.4%, the highest accuracy was when all variables were used in the direct method. In dimensional groups, the length dimensional group had the highest accuracy (84.6%), and MINB (body of calcaneus) and MAXL (maximum calcaneal length) could be used as a single measurement. Most Korean females were misclassified as males using the equations of other population groups, and this finding demonstrates the necessity of population-specific equations.

Identification using frontal sinus by three-dimensional reconstruction from computed tomography.

Radiographs and computed tomography (CT) images have been increasingly applied and accepted in forensic sciences. Along with radiographs and CT images, the frontal sinus is often used for the individual identification because of its unique and unchangeable characteristics. The purpose of this study is to define the usefulness of three-dimensional (3-D) images of the frontal sinus for identification. CT images from 119 Korean cadavers were built up for 3-D reconstruction and surveyed with 15 measurements. The total volume of the sinus, some nonmetric characteristics, and the bilateral asymmetry index in men differed significantly from those in women (p < 0.05). The digit codes, six sections and 10-digit number, were almost able to accurately identify individuals (98%). This study showed a statistical difference between the sexes and classified the fused and prominent middle sinuses for the first time. This proposed method for identification is more accurate than those used in other studies.

Sex determination from the talus of Koreans by discriminant function analysis.

The aims of this study were to investigate the sex discriminating potential of the talus in Koreans and compare this with other analyses in different populations. Statistical analyses were performed using data from nine measurements acquired from 140 tali (70 men, 70 women). The talus of Koreans is dimorphic between sexes in all measurements (p < 0.01). Discriminant function equations were generated by univariate, multivariate, and stepwise methods with a range of accuracy from 67.1 to 87.1%. Stepwise equations of other populations did not discriminate the sex of the Korean sample as accurately as each equation's own accuracies. The variables with high accuracy in this study are useful for sex determination of Koreans on the basis of confirmation of population specificity.

The posterior meniscofemoral ligament: morphologic study and anatomic classification.

The meniscofemoral ligaments (MFLs) run from the medial femoral condyle to the posterior horn of the lateral meniscus and consist of anterior MFL (aMFL) and/or posterior MFL (pMFL) components according to whether it passes anterior or posterior to the posterior cruciate ligament (PCL). The purpose of this study was to analyze the incidence and morphologic features of the MFLs in Koreans and formulate an anatomic classification system of MFLs to aid the detailed interpretation of medical imaging or biomechanical data. One hundred knees from 52 cadavers were studied. Eighty-seven knees had pMFLs, whereas an aMFL was only found in one knee from a male cadaver. The pMFLs and PCLs were longer in males than in females (P < 0.05). The most common type of MFL was the high crossing of a typical pMFL against the PCL in both genders. Regarding other types, the incidence of absent pMFLs was higher in males than in females and the oblique bundle of the PCL was easily confused with the pMFL in several cases in both genders. These results provide the basis for the classification system of the MFL and will contribute to better outcomes for evaluating the MFL and PCL when using medical imaging such as arthro-CT scan or MRI through a better understanding of the anatomy of the MFL and PCL.

Variation of the infrahyoid muscle: duplicated omohyoid and appearance of the levator glandulae thyroideae muscles.

The embryologic origin of the omohyoid muscle is different from that of the other neck muscles. A number of variations such as the absence of muscle, variable sites of origin and insertion, and multiple bellies have been reported. However, variations in the inferior belly of the omohyoid muscle are rare. There have been no reports of the combined occurrence of the omohyoid muscle variation with the appearance of the levator glandulase thyroideae muscle. Routine dissection of a 51- year-old female cadaver revealed a duplicated omohyoid muscle and the appearance of the levator glandulae thyroideae muscle. In this case, the two inferior bellies of the omohyoid muscle were found to originate inferiorly from the superior border of the scapula. One of the inferior bellies generally continued to the superior belly with the tendinous intersection. The other inferior belly continued into the sternohyoid muscle without the tendinous intersection. In this case, the levator glandulae thyroideae muscle appeared on the left side, which attached from the upper border of the thyroid gland to the inferior border of the thyroid cartilage. These variations are significant for clinicians during endoscopic diagnosis and surgery because of the arterial and nervous damage due to iatrogenic injuries. The embryologic origins of the omohyoid and levator glandulae thyroideae muscles may be similar based on the descriptions in the relevant literature.

Reliability of vascular territory for a circumflex scapular artery-based flap.

BACKGROUND: The objective of this study was to evaluate the cutaneous vascular territories of the circumflex scapular artery and the areas supplied by perforators from neighboring anatomical vascular territories, and also to define the safety limits of circumflex scapular artery-based flaps by means of fresh cadaver injection studies. METHODS: A total of 15 dorsal thoraxes from eight fresh cadavers were used in this study. After saline irrigation, contrast medium was injected into the subclavian artery of each specimen. Each full-thickness specimen of the posterior hemithorax was then radiographed to characterize vascular networks. RESULTS: The primary zone of the circumflex scapular artery was calculated to be 93.8 +/- 16.1 cm, which occupies a region smaller than that of the scapula. However, by capturing the secondary zone, which was composed of the territories supplied by adjacent perforators of the thoracodorsal artery, the dorsal intercostal artery, and the transverse cervical artery, potential flap survival dimensions extended beyond the scapular region. In fact, the potential zone was increased to 307.7 7 +/- 55.3 cm, which extended beyond the scapular spine, the inferior angle of the scapula, the posterior axillary line, and close to the midline of the back. CONCLUSIONS: The circumflex scapular artery is an appropriate source for harvesting a large fascial and fasciocutaneous flap based on a single perforating vessel. Surgeons should understand the limits of the circumflex scapular artery-based flap to make best use of it.

An abnormal muscle in the superficial region of the popliteal fossa.

An abnormal muscle was observed in the superficial region of the popliteal fossa during a dissection procedure conducted for medical students. This abnormal muscle originated from the biceps femoris tendon and inserted into the medial head of the gastrocnemius muscle. The innervating nerve branched from the lateral sural cutaneous nerve. The distributing artery arose from a branch of the sural artery. This abnormal muscle mostly comprised one sheet of muscle mass (not tendon type) and ran transversely.

The marginal mandibular branch of the facial nerve in Koreans.

The marginal mandibular branch (MMB) has a particular risk of injury during surgical procedures in the submandibular region, especially over the lower border of the mandible. The facial nerve has been described in many studies, but the MMB is dealt with generally as a branch of the facial nerve. The purpose of this study was to document the anatomy of the MMB by correlation with anatomical landmarks. Eighty-five facial halves were examined for this study. The MMB was classified according to the number of branches and their connections with other branches, and by its relationship with landmarks of the gonion, facial artery, and retromandibular vein. The MMB showed one (28%), two (52%), three (18%), or four branches (2%) where it exited the parotid gland. Classification was based on connection with other branches. Type I (60%) did not communicate with other branches. Type II (40%) communicated with the buccal or cervical branches, or with another branch of the MMB. The cervicofacial division coursed along the lateral aspect of the retromandibular vein in 83% of specimens. The MMB passed the facial artery superficially (42%), passed it deeply in 4%, and ran on both sides of it in 54% of the facial halves. The distribution of the MMB formed a quadrilateral with angles +19.8 mm, -8.1 mm, +30.0 mm, and -15.3 mm measured from two sides on the inferior border of the mandible. These topographical data should help to decrease the incidence of injuries during surgery on the submandibular regions in Koreans.

The spinal root origins and clinical implications of the lower subscapular nerve.

The purpose of this study was to define the spinal root origins of the lower subscapular nerve and the amounts of participating nerve fibers from each spinal root and to discuss the clinical implications. Using a method of separating the nerve fascicles that traces the particular nerve fibers at the intrafascicular level, the spinal root origins of the lower subscapular nerve appeared as two types. The first type comprised 76.9% and was composed of the C5, C6, and C7 roots; the second type comprised 23.1% and was composed of the C6 and C7 roots. The number of nerve fibers was 357.2 +/- 139.7 (mean +/- SD) derived from C5, 1070.4 +/- 390.6 from C6, and 500.0 +/- 285.4 from C7. The nerve fascicles comprising the lower subscapular nerve traveled within the partially common fascicles composed of the axillary nerve. Therefore, injury of the lower subscapular nerve may be accompanied by a lesion of the axillary nerve, which generally consists of C5 and C6 roots composing the posterior cord of the brachial plexus.

Assessment of histomorphological features of the sternal end of the fourth rib for age estimation in Koreans.

The aim of this study was to assess the histomorphological features of the fourth rib and to develop age-predicting equations for Koreans. Sixty-four rib samples (36 males and 28 females) obtained from forensic cases were used for developing equations. Two thin sections (<100-microm thick) per sample were prepared by manual grinding. Multivariate analysis of covariance revealed statistically significant differences in age-adjusted histomorphological variables between sexes. Using stepwise regression analysis, osteon population density and average osteon area were correlated with unknown sex (r2 = 0.826), and sex plus two histomorphological variables provided the best results for an age-predicting equation given the assumption of knowing the sex of a specimen (r2 = 0.839). Average Haversian canal area had little influence on age estimation for male or female samples, and relative cortical area was not significantly related to age for any specimen.

Morphometrics of the hyoid bone for human sex determination from digital photographs.

The identification of unknown remains is very important. When unknown remains are found, anthropologists first determine their sex and age. The sex of most skeletons is determined by their shape. In the hyoid bone, the shape is sex related, so it can be used forensically to determine the sex. This study focused on sex-based morphometry of the hyoid bone in Koreans using digital photographs. Hyoid bones from 52 males and 33 females were examined. For each subject, we took 34 measurements from photographs using a computer program, and the data were analyzed statistically using SPSS 11.0. Twenty-one of 34 measurements had significant sex differences (p<0.05). The discriminant functions based on three measurements (X(1)-X(3)) were as follows: The accuracy of discriminant functions is 88.2% in both groups, so these can be used to distinguish males from females in a statistically significant manner.