Stature estimation of modern Thais from long bones: A cadaveric study.

Objective: The lengths of long bones of adult skeletons are commonly used to estimate stature. The regression equations for calculating stature were established from the relationship between the height and the length of long bones. Methods: We measured 275 adults, ranging in age from 25 to 97 years. The length of six long bones; humerus, radius, ulna, femur, tibia and fibula were measured out. For both femur and tibia, they were measured in 2 different methods; maximum length and anatomical length. Microsoft Excel 2003 and Minitab 14, a statistical computer software (α = 0.05) were used to calculate and establish the regression equations for stature estimation of three groups of the differently sexual identification; male, female and unknown sex. Results: The length of two long bones, especially femur (max) + tibia (max) provides the most accuracy of stature estimation in all three groups. For the one long bone length, femur is the most accurate in every group. Conclusion: The overall of the results show that the upper extremities present the accuracy of stature estimation more than the lower extremities (except femur) in the male group. On the other hand, femur, tibia and fibula of the female group provide more accurate stature estimation than the upper extremities.

Anatomic variations of the superficial part of cervical plexus and its branches in Thais.

Objective: To evaluate the variations of superficial part of cervical plexus and its branches in Thais. Methods: We dissected bilaterally in 108 cervical plexuses in Thai cadavers. The anatomic variations of origins and its cutaneous branches of the superficial part of cervical plexus were identified and recorded. Results: The superficial part of cervical plexus derived from the ventral rami of C2, C3, and C4. Its branches consisted of the lesser occipital, great auricular, transverse cervical and supraclavicular nerves. These cutaneous (or superficial) nerves mainly derived from ventral rami of C2-C3 except the supraclavicular nerve from C3-C4. They supplied the skin and superficial structures of the head, neck and shoulder. The anatomic variations of these nerves occurred in both sides. There was no statistical difference with regard to either gender or side. Conclusions: The knowledge of the anatomic variations of cutaneous branches of the superficial cervical plexus from this study could be useful for clinicians in anesthesia blocks, surgical procedures, treatment of pain and abnormalities relating to these cervical nerves.

Accuracy of cranial and mandible morphological traits for sex determination in Thais.

Objective: To evaluate the accuracy of sexual dimorphism in the cranium and mandible of Thais using Krogman’s cranioscopy and the modified Krogman’s cranioscopy traits by grading and measurement. Methods: Data were from 101 dry adult skulls (66 males and 35 females) residing in central Thailand. Results: Sex determination using Krogman’s cranioscopy by an inexperienced person had a very high accuracy of 95.5% for males, 82.9% for females respectively and 91.1% overall. According to modified Krogman’s cranioscopy traits by grading, males had larger supraorbital tours, a rougher glabella region and more external occipital protuberance than females. Regarding modified Krogman’s cranioscopy trait by measurement, males had a wider base and a higher mastoid process, with longer and wider occipital condyles than females. Both later methods were also useful in the sexing of fragmented skulls. Conclusion: The cranioscopy study based on 14 traits according to Krogman’s cranioscopy is the best method for sex determination of individual unknown skulls. The modified Krogman’s cranioscopy trait by grading and by measurement is simplified and can very well predict the sexing of fragmented skulls.

Cranial suture closure and age determination in the Thai population.

Objective: To determine whether the time of cranial suture closure in the Thai population has changed compared to findings in the past or not. Is there any difference between sexes? Also to determine the difference between the time of ectocranium and endocranium closure and their reliability for age determination in the Thai population. Methods: The time of closure of the sagittal, coronal and lambdoid sutures was studied in 166 crania (known age Thai adults, 30 females and 136 males) for which the medicolegal autopsies were performed at the Department of Forensic Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok,during the year 2006, age range between 15 to 83 years old. The sagittal suture was divided into four segments and those of each side of the coronal and lambdoid sutures into three segments. The degree of suture closure was recorded for endocranial and ectocranial sides by our scoring system. The sum of all endocranial suture scores, which were also defined as “Composite scores”, were divided into 7 stages (designated as S0-S6). The graph showing the association between chronological age and endocranial composite scores was plotted. The correlation coefficient, chi-square tests, and independent t test were used for statistical analysis, P value <0.05 was statistically significant. Results: It was found that the Thai new generation’s ectocranial suture closure starts and completes earlier than those in the past while endocranial sagittal suture closure starts and completes at a similar time as found in the past. Endocranial sutures start closing before ectocranial and endocranial closure is more related to age than another and no difference between sexes could be found. Using the closure of each suture separately to determine the age at death, somehow, may not be appropriate while using the sum of suture scores reduces variations. The sum of endocranial suture scores (composite scores) are statistically proven to be most related to age without significant statistical difference between the two sexes. The association between age and the interval of composite scores was shown andsuggested to be the age predicting tool. Conclusion: The time of cranial suture closure is stated as one of indicators of age at death but its progression variesgreatly. According to our study, using composite scores helps in diminishing this variation. The information on suture closure is useful when other criteria are not available or when being used in conjunction with other attributes.

Sex determination in Thai skulls by using craniometry: Multiple logistic regression analysis.

Objective: To evaluate sexual dimorphism in the cranium and mandible of Thais by using Jorgensenûs craniometry and to develop a statistical model to determine sex from craniometrical measurements and indices. Methods: One hundred and one Thai skulls (66 males and 35 females) which ranged in age from 18 to 86 years were studied. Results: According to craniometry, the skull of a male is larger and higher than that of a female. Considering each individual measurement, although 26 of 30 measurements and 5 of 14 indices showed a statistically significant difference between males and females, they had some overlaps. To predict gender more accurately, a multiple logistic regression model based on 4 skull measurements (mm) i.e., nasion-basion length (M5), maximum breadth of the cranium (M8), facial length (M40), and bizygomatic breadth of the face (M45) was developed as follows: In (odds) = Z = -52.5312 + 0.27 M5 - 0.1867 M8 + 0.1268 M40 + 0.319 M45 The probability of being males (P) is then ez/(1+ez). Using a cut off point for P of 0.5, this logistic model could correctly predict 82.9% (95% CI: 66.4%, 93.4%) of females and 92.1% (95% CI: 82.4%, 97.4%) of males respectively with the overall accuracy of 88.8% (95% CI: 80.8%, 94.3%). Conclusion: Jorgensenûs craniometry of the cranium and mandible can be used to determine gender among Thais via a multiple logistic regression model on M5, M8, M40 and M45.

The acromial morphology of Thais in relation to gender and age: study in scapular dried bone.

OBJECTIVE: The objective of the present study was to determine the acromial shape and examine if there is a correlation between the acromial morphology and genders, ages and sides. MATERIAL AND METHOD: The present examined 154 dried Thai scapulas (107 males and 47 females) with age range from 16 to 87years (mean = 49 + 17 years). The acromial morphology of each scapula was studied by the computerized image analysis of digitized photography through the supraspinatous outlet view, with the distance (M) measured from its anterior to posterior end, the height (H) of the resultant curve and the distance (N) from the anterior end to the point perpendicular to the height. The acromial types were defined as type I (flat), II (curved) and III (hooked) with the criteria that N is more than or equal to the 2/3, 1/3 and less than 1/3 of M, respectively. RESULTS: The incidences of types I, II and III were 3.2%, 93.5% and 3.2%, respectively. It was found in both sexes, female (93.6%) and male (93.5%) and in both sides, left (96%) and right (91.1%). With respect to the age range, type II were found in 100% of subjects of less than 30 years, 4.5% in those between 30-60 years, were 4.5% (1), 93.2% (1), 2.3% (111). Those more than 60 years old were 2.3 %(1), 90.7% (11) and 7.0% (III). The spur formation on the anterior end of the acromion was found in 14.9% of scapulas, curved type mostly; and it was associated with hooked type in only one scapula. CONCLUSION: There was no significant type difference between sex, side and age range (p > 0. 05). The spurs found are not related to acromial morphology and old age.

Anatomic variations of the sacral plexus in Thais.

The aim of this study was to examine the variation of the sacral plexus in Thais in terms of its origin, branches, and variation in each branch. Anatomical dissections were conducted in 150 halves of formalin-embalmed cadavers. All preserved cadavers were Thais, ranging in age from 35 to 85 years old, 86 males and 64 females. The sacral plexus was markedly comprised of the fourth lumbar to fourth sacral ventral rami (L4-S4) in 98.67% of the plexuses (or 148 cases) except for two plexuses (1.33% of the plexuses) those were derived from the ventral rami of the fourth lumbar to fifth sacral ventral rami (L4-S5). The sacral plexus, lying on the posterior wall of the lesser pelvis to the piriformis muscle, has nine named branches. Six of these are distributed to the buttock and lower lomp, including 1) Nerve to the Quadratus Femoris and Gemellus Inferior, 2) Nerve to the Obturator Internus and Gemellus Inferior, 3) Superior Gluteal, 4) Inferior Gluteal, 5) Posterior Femoral Cutaneous and 6) Sciatic. The other branches supply structures belonging to the pelvis, including 7) Nerve to the Piriformis, 8) Pudendal and 9) Pelvic Splanchnic. The variant of origination and formations of all branches occur on both side. However, the anatomic variability of the plexuses was not statistically different with regard to either side or gender. The results from this study provided additional information and new insights into the sacral plexus in terms of its origins, branches, and variations of each branch that might be useful in medicine, anesthesia, surgery and physical therapy.

Anatomic variations of the lumbar plexus in Thais.

The aim of this study was to examine the variation of the lumbar plexus in Thais in terms of its origin, branches, and variation of each branch. Anatomical dissections were conducted in 150 halves of formalin-embalmed cadavers. All preserved cadavers were Thais, ranging the age from 35 to 85 years old, 86 males and 64 females. The lumbar plexus was markedly composed of the first to fourth lumbar ventral rami (L1-L4) in 81.33% of the plexuses (or 122 cases), but its origin varied, as it was derived from the ventral rami of the twelfth thoracic to fifth lumbar ventral rami (T12-L5) in 18.67% of the cases. Eight branches of the plexus were found, including seven typical branches and an additional branch. The seven typical branches occured in 100% of cases, and they were the iliohypogastric, ilioinguinal, genitofemoral, lateral cutaneous nerve of the thigh, femoral, obturator nerve and lumbosacral trunk. The additional branch, the accessory obturator nerve occurred in only 3.33% of the cases. In conclusion, the variation pattern of the plexuses occurred on both sides. However, the anatomic variability of the plexuses was not statistically different with regard to either side or gender. The result from this study provided additional information different with regard to either side or gender. The results from this study provided additional information and new insights into the lumbar plexus in terms of its origins, branches, and variations of each branch that might be useful in medicine, anesthesia, surgery and physical therapy.

Microvascularization of the midbrain in lylei’s flying fox (Pteropus lylei).

Midbrain vascular casts of the Lylei’s flying foxes (Pteropus lylei) were prepared by infusion of Batson’s No.17 plastic mixture into the blood vessels and examined by stereomicroscopy and scanning electron microscopy. Histological study of the midbrain was also performed. It was found that the midbrain of Lylei’s flying fox was supplied by the branches of the vertebrobasilar system. These branches gave off the penetrating arteries, which coursed radially into the internal part of the midbrain to ward the cerebral aqueduct. These arteries, which could be divided into anteromedial, anterolateral, posterolateral and posteromedial groups, according to the points of entry and supplying areas. The arteries ramified into arterioles and capillaries, respectively. The density of the capillary network in the midbrain was closely related to the density of the nerve cells in midbrain nuclei. Less vascularity was found in the areas occupied by nerve fibers. The arterial anastomoses could be observed on the surface of the midbrain. The venous drainage in the midbrain could be divided into three major groups according to the areas of drainage. Firstly, anterior or petrosal group drained the blood from the areas ventral to cerebral aqueduct into the superior petrosal sinus. Secondly, the superior or galenic group emptied the venous blood from the thalamocollicular and dorsal aqueductal veins into the great cerebral vein of Galen and rectus sinus, respectively. Thirdly, the posterior group collected blood from the collicular veins into the rectus sinus. Finally, both rectus and superior petrosal sinuses drained into the external jugular vein and partially into the internal jugular vein.

Anatomical variation course of the lateral femoral cutaneous nerve as it exits the pelvis in Thais from the central region.

The aim of this study was to examine in detail the course and location of lateral femoral cetaneous nerve (LFCN) as it emerges from the pelvis in Thais. The anatomy of the LFCN was studied through the dissection of 107 halves of formalin-embalmed Thai cadavers ranging in age from 37 to 94 years. The LFCN is formed by the union of posterior divisions of ventral rami of the second and third lumbar spinal nerves (L2 – L3). The site at which the nerve exits the pelvis is quite variable. Depending on the anatomical location which varies from superficial and posterior, to medial and deep, to anterior superior iliac spine (ASIS) and origin of the sartorius muscle, five different types as identified by Aszman et all1 were confirmed : type A, posterior to the anterior superior iliac spine across the iliac crest (1.86%); type B, medial to the anterior superior iliac spine and ensheathed in the inguinal ligament (9.34%); type C, medial to the anterior superior iliac spine and ensheathed in the tendinous origin of the sartorius muscle (46.72%); type D, medial to the anterior superior iliac spine located in the interval between sartorius muscle and iliopsoas muscle deep to the inguinal ligament (40.18%); type E, medial to the anterior superior iliac spine, deep to the inguinal ligament, overlying the iliopsoas fascia, and contributing the femoral branch of genitofemoral nerve (1.46%). The majority of the LFCN course and location as it exits the pelvis are type C (46.72%), and type D (40.18%). There is no statistical difference with regard to either gender or side of thigh.

Anatomical variations of the ansa cervicalis in Thais.

The aim of this study was to examine the variation of ansa cervicalis in Thais in terms of its origin, formation and relation to the great vessels of the neck. Anatomical dissections were examined bilaterally in 108 cervical plexuses of Thai cadavers ranging in age from 34 to 87 years. There were 57 male and 51 female cervical plexuses. The ansa cervicalis which consists the first to third cervical ventral rami (C1-C3), is formed by the junction of the superior and inferior roots. Its anatomical course and morphology are complicated by the variable lengths, origins, and relations with the great vessels of the neck. Twenty types of ansa cervicalis were classified into 5 different groups according to the length of ansa loop as compared with the level of cricoid cartilage and the relation of the inferior root of the ansa to the internal jugular vein. Depending on the origins of the inferior and superior roots, each group consisted of various types. Group I and II had long ansa loops with the inferior root lying lateral to the internal jugular vein in group I, and nedial to the vein in group II. Similarly, group III and IV had short loops of the ansa with the inferior root lying lateral to the internal jugular vein in group III, and medial to the vein in group IV. However, group V was not related to the criteria. It was suggested that the majority of ansa cervicalis were found to be group IV and group I. The variation of ansa cervicalis patterns occurred in both sides. This was not statistically different with regard to either gender of side. The results of this study provide additional information and new insights into the variation of the ansa cervicalis which may have useful applications in laryngeal reinnervation surgery and anrsthesia.

Non-rotation of the midgut in adults.

Two cases of non-rotation of the midgut were detected in cadaveric bodies from the Department of Anatomy, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. They were both female, aged 83 and 32, respectively. In both cases, the duodenum, jejunum, ileum, and colon lay in the unrotated position with the small intestine occupying the right half and the large intestine occupying the left half of the abdominal cavity. Additionally, the duodenojejunal junction remained on the right side of the abdomen, whereas the caecum and ascending colon lay in the midline, with the terminal ileum entering the right side of the caecum. The appendix entered the left side of the caecum. Interestingly, they had had no clinical symptoms during life. These abnormalities implied that midgut rotation during embryonic period occurred only as far as 90-degrees counterclockwise instead of the usual 270-degree rotation. To our knowledge, this is the first report of asymptomatic non-rotation of the midgut in Thailand. The variation found in the present study provides additional information concerning the variation seen in human anatomy and should be considered in patients with atypical symptoms related to the gastro-intestinal tract.

The persistence of the median aretery in Thais.

The median artery is a main artery that supplies hand in embryonic period. When the radial and ulnar arteries are well developed, the median artery becomes smaller and soon disappeared. In order to find the incidence of persistant median artery in Thais, we study 266 upper extremities in our Department, 133 of right sides and 133 of left sides. The persistant median artery is found in 22 extremities, or 8%. Further studies reveal that, 77% of median artery are the branch of ulnar artery, 9% of common interosseous artery and 14% of brachial artery. 91% of median artery accompany the median nerve throughout forearm, while 9% traveling superficially in the same plane as supper veins. All of median artery end by joining superficial palmar arch. 95% pass deep to flexor retinaculum, only 5% pass superficial to this retinaculum before joining superficial palmar arch.

Anomalies of the popliteal artery and Its main branches in Thais.

The pattern of origin, course, branching and termination of the popliteal artery of 440 lower extremities of Thai cadavers was recorded with right-side supply being 224 and left-side 216. Various types of anomaly were found. In one lower extremity, the popliteal artery arose as a direct continuation of the sciatic artery instead of the femoral artery as normal. The femoral artery in this was very small. In the popliteal fossa, 2lower extremities showed the popliteal artery passing anterior to the popliteus muscle and 6 lower extremities showed the anterior tibial artery passing anterior to the popliteus muscle. In 33 lower extremities (7.5%), the popliteal arteries did not terminate at the lower border of the popliteus muscle. We found 3 levels of termination: on the posterior surface of the popliteus muscle (10 lower extremities), proximal to the upper border of the popliteus muscle (10 lower extremities) and distal to the lower border of the popliteus muscle (13 lower extremities). Abnormal patterns of branching of the main branches of the popliteal artery were found in 67 of the 440 lower extremities i.e., 15% and they were divided into 11 types. Each type of variation can be described by its development.

Morphology of the axis in Thais.

These metrical and morphological studies of the axis, were based on the axis of 120 Thais, 60 male and 60 female. The measurements included the dimensions of dens, vertebral foramen, anteroposterior and transverse diameter of the axis. All of the dimensions and sexual dimorphism were compared using statistical methods. The results and statistical values of the measurements were illustrated in tabular form. Qualitative observation concerning the shape of dens near the basal regions were reported. In all measurements, the average values of males were greater than those of females. Judging from the statistical analysis, no sex difference was apparent in the mean height of dens and mean diameters of vertebral foramen.

Development of the urinary system: Serial section study of 4 and 6 mm rat and 10 mm pig embryos.

The urogenital system develops from the intermediate mesoderm, the coelomic epithelium and the endoderm of the urogenital sinus. The urinary system of mammals is characterized by three sets of kidney: the nonfunctional pronephroi, the mesonephroi and the functional metanephroi. The metanephroi or the permanent kidneys develop from the metanephric diverticulum and metanephrogenic tissue. At first the kidneys are located in the pelvis but later gradually ascend to the abdomen. The urinary bladder develops from the urogenital sinus and surrounding splanchnic mesoderm. In studying the development of the human urinary system at the Department of Anatomy, Siriraj Hospital, we have employed serial sections of 10-15 mm pig embryos as laboratory models. This method of study is helpful in understanding and recognizing how the kidney forms. However, pig embryos are not commercially available anymore, it is necessary to study the normal development of the kidney in other mammals. This study demonstrates that 6 mm rat embryos can be used instead of pig embryos as the development of the metanephros is very similar, although, in the rat embryo, the mesonephros is much smaller than that of a pig embryo and the subcardinal vein cannot be identified. However, it should be borne in mind that the human mesonephros is also smaller than that of pigs. For this reason, the rat embryo is still suitable for use as a laboratory model.

The development of the mice embryo’s heart.

Serial sections of 4-6 mm mice embryos were carefully studied in relation to the serial sections of 10 mm pig embryos under a light microscope to compare the development of the heart and related blood vessels. The heart of a 4-6 mm mouse embryo has incompletely divide chambers comprising two atria and two ventricles. The partition of the atrium, i.e. the septum primum, begins to from at the 4 mm stage and two ventricles. The partition of the atrium, i.e. the septum primum, begins to from at the 4 mm stage and completely attaches to the endocardial cushion at the 6 mm stage. The rupture of the septum primum brings about communication between the two atria, the foramen secundum. Communication between the two ventricles is also by the interventricular foramen. The right atrium receives venous blood from the right horn of the sinus venosus, which is larger than that of the left side. The bulbus cordis communicates with the right ventricle and brings blood to the aortic sac which extends branches to the branchial arches to join the dorsal aorta. The heart of 4-6 mm mice embryos is highly similar to that of a 10 mm pig embryo. Since mice embryos are very easy to obtain for slide preparation, there would be no problem in using mice embryos instead of pig embryos for the study of the development of the heart.

Development of the face and nasal cavities.

The human face develops mainly between the fifth and eighth weeks, following conception. Its development can be traced to five facial primordial appearing around the stomodeum early in the fourth week. There are : one frontonasal, two maxillary and two mandibular prominences. By the end of the fourth week, two nasal placodes develop on each side of the lower part of the frontonasal prominences. The early development of the human face is similar to that of other mammals, such as the pig and rat, all of which acquire branchial arches in the early development stage. The rat branchial arches develop at the 4 mm stage and nearly disappear at the 6 mm stage, as the second one grows dorsally and obliterates the cervical sinus. The medial and lateral nasal prominences appear at the 4 mm stage, and at 6 mm the nasal cavities are more extensive than those of a 10 mm pig embryo ; they are at the same stage of development as a 15 mm pig embryo. Currently we use 10 and 15 mm pig embryos as models in studying facial and nasal development. However, in the future, it might be more suitable to use 4 and 6 mm rat embryos because they are easier to obtain.

Development of the respiratory system serial section study of 6 and 12 mm rat and 10 mm pig embryos.

The human lower respiratory system begins to form about day 26-27 after conception, and is first indicated by a median larngotracheal groove in the caudal and of the ventral wall of the larynx, trachea, bronchi and the pulmonary lining epithelium. The connective tissue, the cartilage and the smooth muscle of these structures develop from the splanchnic mesoderm surrounding the foregut. In studying the development of the respiratory system at the Department of Anatomy, Siriraj Hospital, Medical students should trace the serial section of 10 mm and 15 mm pig embryos. In doing this, they be able to observe the layngotracheal groove at the floor of the pharynx and when, tracing the sections caudally, they will be able to observe the trachea, esophagus and the bifurcation of the trachea to from primary bronchi as well as the smaller branches of bronchi. The present study attempts to show the development of the respiratory system of rat embryos in order to find the most suitable stage which can be used as a laboratory model for use by students. A 6 mm rat embryo can be used instead of a pig embryo for studying the development of the respiratory system, if pig embryos are not available.

Development of the branchial apparatus in rat, pig and chick embryos.

Serial sections of 4-6 mm rat embryos were carefully studied in relation to the serial sections of 36-somite chick embryos and 10 mm pig embryos under a low-power microscope to compare the development of their branchial apparatus. Four pairs of the branchial arch could be clearly identified in the 4 mm rat embryos, the first two being more prominent than the others. The aortic sac or the ventral aorta, the continuation of the truncus arteriosus, is located between the right and left hyoid arches. The thyroid diverticulum passes the aortic sac to attain its final position at the caudal region. Each aortic arch branches from the aortic sac and passes through the mesenchyme of each branchial arch to join the dorsl aorta. The branchial apparatus of the 4-5 mm rat embryos is highly similar to that of the 36-somite chick embryos and 10 mm pig embryos. Since the rat embryos are very easy to obtain for slide preparation, there is no significant problem in the use of rat embryos to study the development of the branchial apparatus instead of the pig embryo.