Sex estimation by femur in modern Thai population.

Sex estimation is an important step of postmortem investigation and the femur is a useful bone for sex estimation by using metric analysis method. Even though there have been a reported sex estimation method by using femur in Thais, the temporal change related to time and anthropological data need to be renewed. Thus the aim of this study is to re-evaluate sex estimation by femur in Thais. 97 adult male and 103 female femora were random chosen from Forensic osteology research center and 6 measurements were applied tend to. To compare with previous Thai data, mid shaft diameter to increase but femoral head and epicondylar breadth to stabilize and when tested previous discriminant function by vertical head diameter and epicondalar breadth, the accuracy of prediction was lower than previous report. From the new data, epicondalar breadth is the best variable for distinguishing male and female at 88.7 percent of accuracy, following by transverse and vertical head diameter at 86.7 percent and femoral neck diameter at 81.7 percent of accuracy. Multivariate discriminant analysis indicated transverse head diameter and epicondylar breadth performed highest rate of accuracy at 89.7 percent. The percent of accuracy of femur was close to previous reported sex estimation by talus and calcaneus in Thai population. Thus, for especially in case of lower limb remain, which absence of pelvis.

New models for age estimation and assessment of their accuracy using developing mandibular third molar teeth in a Thai population.

Age estimation using developing third molar teeth is considered an important and accurate technique for both clinical and forensic practices. The aims of this study were to establish population-specific reference data, to develop age prediction models using mandibular third molar development, to test the accuracy of the resulting models, and to find the probability of persons being at the age thresholds of legal relevance in a Thai population. A total of 1867 digital panoramic radiographs of Thai individuals aged between 8 and 23 years was selected to assess dental age. The mandibular third molar development was divided into nine stages. The stages were evaluated and each stage was transformed into a development score. Quadratic regression was employed to develop age prediction models. Our results show that males reached mandibular third molar root formation stages earlier than females. The models revealed a high correlation coefficient for both left and right mandibular third molar teeth in both sexes (R = 0.945 and 0.944 in males, R = 0.922 and 0.923 in females, respectively). Furthermore, the accuracy of the resulting models was tested in randomly selected 374 cases and showed low error values between the predicted dental age and the chronological age for both left and right mandibular third molar teeth in both sexes (-0.13 and -0.17 years in males, 0.01 and 0.03 years in females, respectively). In Thai samples, when the mandibular third molar teeth reached stage H, the probability of the person being over 18 years was 100 % in both sexes.

The Accuracy of Sex Estimation on Metatarsal Bones in a Northeastern Thai Population.

BACKGROUND: This study was carried out to evaluate the accuracy of sex estimation by discriminant analysis and stepwise discriminant analysis equations generated from metatarsal bones in a Thai population. MATERIAL AND METHODS: The testing samples utilized in this study consisted of 50 skeletons (25 males and 25 females) obtained from the Khon Kaen University Skeletal Collection, Department of Anatomy, Faculty of Medicine, Khon Kaen University. Seven measurements of metatarsal bones were measured in centimeters, using either a mini-osteometric board (MOB) or a sliding caliper. The values measured from the Khon Kaen Skeletal Collection were used to determine the accuracy and applicability of sex determination, as predicted by Y1-Y6 equations which were generated from a Chiang Mai Skeletal Collection. RESULTS: The percentage of sex determination accuracies predicted from the Y1-Y6 equations demonstrated accuracy rates of 80-95.6. CONCLUSIONS: The Chiang Mai sex determination equations, generated from metatarsal bones by discriminant analysis (Y1-Y3) and stepwise discriminant analysis (Y4-Y6), demonstrated high accuracy rates of prediction, suggesting that these equations may be useful for sex determination within the Thai population.

Test of Sex Estimation Equations on Carpal Bones in a Northeastern Thai Population.

BACKGROUND: Sex assessment is an essential step in person identification, both in forensic and anthropological contexts. Many parts of skeletal remains such as skull, pelvis and long bones have been proven to be useful in determining sex. However, literature has shown that short bones such as carpal bones are also sexually dimorphic. In the last few years, there was an unpublished study using lunate, scaphoid and hamate from bone collection in Northern Thailand to create 6 discriminant equations to assess sex. The objective of this study was to investigate the application of those equations in the sample from other parts of Thailand. MATERIALS AND METHODS: A sample of 50 individuals (25 males and 25 females), kindly supplied by Department of Anatomy, Khonkaen University, Khon-kaen, Thailand, was examined. The age of the individuals ranged from 48-87 years old for males and 38-87 years old for females. RESULTS: The classification accuracies ranged from 82%-98% with right hamate yielding the highest accuracy. CONCLUSIONS: These results proved the applicability of those 6 discriminant equations in a population from Northeastern Thailand. Further studies should include population from other parts of Thailand.

New Method of Age Estimation from Maxillary Sutures Closure in a Thai Population.

Age estimation is one of the major components of forensic identification. Cranial suture closure has long been used as indicator for age estimation. Maxillary sutures have been less studied for estimation of age at death because they vary in their timing of closure with age. The purpose of this study was to estimate age by examining 190 Thai skulls with age ranging between 15-93 years from Forensic Osteology Research Center, Faculty of Medicine, and Chiang Mai University. Four parts of maxillary suture (incisive, anterior, transverse, and posterior sutures) were investigated the suture obliteration of each suture by computerizing from photograph. The suture were measured by pixel counting.The prediction model which based on the support vector machine (SVM) for regression or support vector regression (SVR) was utilized for data analysis. The results showed high correlation (R2 = 0.9086) between the predicted age and actual age. Plot between actual age group and predicted age in seven groups also revealed high correlation (R2 = 0.9434). These can be implied that we are able to use this SVR model to predict age at death using maxillary suture information.The interesting issue is to further apply this model in more cases to ensure the generalization of the finding. This study is the first attempt to estimate age at death using a new method based on novel analysis which considers a characteristic of relationship between maxillary suture closures with age that are not in linear form. The present study may contribute as a basis knowledge and method for further study of age estimation in archaeological and forensic anthropological contexts, especially when only skull or base of skull are found.

Simultaneous accumulation of magnesium with calcium and phosphorus in aorta and iliac arteries of Thai.

To elucidate compositional changes of arteries with aging, the authors previously investigated age-related changes of mineral contents in the various arteries of Japanese and Japanese monkey. To examine whether there were differences between races in regard to age-related changes of mineral contents and the relationships among element contents in the arteries, the authors investigated the arteries of Thai. The subjects consisted of 13 men and 3 women, ranging in age from 39 to 84 yr. After the ordinary dissection at Chiang Mai University was finished, abdominal aortas, common iliac, internal iliac, and external iliac arteries were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. The contents of calcium, phosphorus, and magnesium became the highest in the fifties in the abdominal aorta, common iliac, and external iliac arteries, whereas the contents of calcium and magnesium became the highest in the sixties in the internal iliac artery, and decreased thereafter. In regard to relationships among element contents, it was found that there were high correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium in all of the abdominal aortas and three iliac arteries. The mass ratios of magnesium to calcium and phosphorus were each similar in the abdominal aorta, common iliac, and internal iliac arteries, except for the external iliac artery, in which it was slightly high. These revealed that as calcium and phosphorus increased in the arteries with aging, magnesium increased in the arteries as well. The differences between the arteries of Thai and Japanese were discussed in the present article.

Incidence of a septum in the first dorsal compartment and its effects on therapy of de Quervain's disease.

Because there has been no study of the presence of a septum in the first dorsal compartment of the wrist in Asians and there is no method of conservative treatment of de Quervain's disease based on the presence of this septum, the authors have evaluated this septum in a large Asian population. Two-hundred wrists in 100 Asian cadavers were dissected. The presence of the septum was documented by removing the abductor pollicis longus (APL) tendon from its tunnel in the first dorsal compartment and observing through the same tunnel if there was a septum to prevent immediate access to the extensor pollicis brevis (EPB) tendor. A septum was present in 77.5% of wrists. When the septum was present, the resultant subcompartment for the EPB was quite narrow. Given the high incidence of the septum, therapy of de Quervain's disease could reasonably be modified accordingly. For instance, to improve the success rate for local steroid injection, the solution of steroid should aim at reaching both subjcompartments by redirecting the course of the injecting needle. As for surgical release, adequacy could be enhanced by the realization by the surgeon of the possible presence of the septum.