Three-dimensional prediction of the nose for facial reconstruction: A preliminary study on North Indian adults.

Forensic facial reconstruction is the last recourse to establish the identity of an unknown skull. The facial soft-tissue thickness (FSTT) is required to reconstruct various facial features on a skull. Unlike other facial features, the nose is made of cartilaginous tissue except for a small nasal bone. A large cavity (pyriform aperture) exists on the skull in place of the nose, which makes it a challenging job for reconstruction. The nose is a vital feature for the recognition of a face. Any change in the shape or size of the nose can alter the original aesthetic of the face. The present study proposes angles and regression functions on the bony structure to predict the various parts of the soft nose. A sample of computed tomography (CT) images of 100 males and 100 females aged between 18 and 45 years were included in the study. Apart from measuring fourteen linear parameters with three angles, simple linear regression models were derived for five pairs of parameters. Pearson's correlation coefficients for most of the parameters ranging between 0.221 and 0.872 were found to be significant at p ≤ 0.05 level. FSTT at three anatomical landmarks of the nose was also measured. A morphological observation study was undertaken to find the most frequent direction of the bony anterior nasal spine (ans) and its relation with the position of the pronasale (prn) on the soft nose. The devised parameters proposed in the study may also prove useful for reconstructing the nose in other populations.

Purkait's triangle revisited: role in sex and ancestry estimation.

Identification of unknown remains recovered from marine and terrestrial locations is a significant humanitarian problem. This investigation proposes a simple method applicable to fragmentary femora for a more refined level of ancestry and/or sex estimation. To that end, we re-examined Purkait's triangle which involves three inter-landmark distances between the traction epiphyses and the articular rim of femoral head. A large sample (n = 584) from geographically diverse (Egyptian, Indian and Greek) populations was compiled. Additionally, shape (n = 3) and trigonometrically derived variables and ratios (n = 9 variables) were employed to detect any geographically-clustered morphological differences between these populations. Random forest modelling (RFM) and linear discriminant function analysis (LDA) were employed to create classification models in instances where sex was known or unknown. The sample was apportioned into training and test sets with a ratio 70/30. The classification accuracies were evaluated by means of k fold cross-validation procedure. In sex estimation, RFM showed similar performance to LDA. However, RFM outperformed LDA in ancestry estimation. Ancestry estimation was satisfactory in the Indian and Egyptian samples albeit the Greek sample was problematic. The Greek samples presented greater morphological overlap with the Indian sample due to high within-group variation. Test samples were accurately assigned to their ancestral category when sex was known. Generally, higher classification accuracies in the validation sample were obtained in the sex-specific model of females than in males. Using RFM and the linear variables, the overall accuracy reached 83% which is distributed as 95%, 71% and 86% for the Egyptian, Indian and Greek females, respectively; whereas in males, the overall accuracy is 72% and is distributed as 58%, 87% and 50% for the Egyptian, Indian and Greek males, respectively. Classification accuracies were also calculated per group in the test data using the 12 derived variables. For the females, the accuracies using the medians model was comparable to the linear model whereas in males the angles model outperformed the linear model for each group but with similar overall accuracy. The classification rates of male specific ancestry were 82%, 78% and 56% for the Egyptian, Indian and Greek males, respectively. In conclusion, Purkait's triangle has potential utility in ancestry and sex estimation albeit it is not possible to separate all groups successfully with the same efficiency. Intrapopulation variation may impact the accuracy of assigned group membership in forensic contexts. Key pointsPurkait's method is a possible ancestry group indicator applicable to fragmentary femora.Random forest model surpassed linear discriminant function analysis in multi-group ancestry classification.Ancestry is more accurately assessed in females than males.The intertrochanteric distance is the most important feature in discrimination of sex whereas in ancestry it was the head to lesser trochanter distance.Sex differences override ancestry due to the tendency of misclassification into same sex but different group rather than the opposite sex of the same ancestry.

Progression of growth in the external ear from birth to maturity: a 2-year follow-up study in India.

BACKGROUND: This study aimed to follow the growth dynamics of auricular dimensions from birth to the age of 18 years. The norms of dimensions at different ages, the peak growth period and the maturity age of the dimensions are essential information to Physicians for early clinical diagnosis or for deciding the optimal time for surgery to correct abnormalities. METHODS: For this study, 2,147 children belonging to central Indian population were measured in at least three sequential sessions. Eight dimensions including the physiognomic length and width of the ear and its morphologic width; conchal length, width, and depth; and lobular length and width were measured using anthropometric technique. Three new dimensions (tragal length and height and maximum width of the antihelix) were introduced in the study. Three indices (auricular, conchal, and lobular) also were derived. RESULTS: Most dimensions exhibited very rapid growth during the first 3-6 months of infancy and thereafter proceeded at a slow pace until adulthood. The smaller dimensions (conchal depth, tragal height, and maximum width of the antihelix) increased continuously throughout the growth period. At birth, most of the dimensions were 52-76 % of their adult size, while tragal length and height were less than half their adult size. Unlike the other dimensions, the lobule length was smaller in males, probably due to the higher frequency of hypoplastic and bow-shaped lobules among them. The width dimensions matured earlier, at 5.6-11 years, whereas the maturity age of lengths varied from 12 to 16 years. CONCLUSIONS: The data generated in the current study will be useful to Physicians as a guideline in correcting auricular deformity and in constructing age progression charts of the external ear. Knowledge concerning the maturation age of the ear will help law enforcement authorities in deciding when to use it for establishing personal identification. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Growth pattern of the eye from birth to maturity: an Indian study.

BACKGROUND: The aim of the study was to follow the growth dynamics of ocular dimensions from birth to 18 years of age. The norms of dimensions at different ages, peak growth period, and maturity age of the dimensions are essential information for a physician in delineating syndromes or in deciding the optimal time for undertaking surgery to correct an abnormality. Lack of a comprehensive study in India has prompted us to undertake our own. METHODS: A total of 1,960 healthy subjects from central India were included in the study. An anthropometric technique was used to measure medial (MICD) and lateral intercanthal distances (LICD), palpebral fissure length (PFL), and derived interpupillary distance (IPD). Two indices incorporating medial intercanthal distance with bizygomatic width (BZW) and maximum head breadth (HB) were derived. RESULTS: During infancy the growth rate of ocular dimensions range from 13 to 23 % in males and from 17 to 30 % in females. After infancy the growth rate falls below average in all dimensions except MICD. MICD matures at 9 and 11 years in females and males, respectively. The other dimensions follow in 2-3 years time. The indices MICD-HB and MICD-BZW vary between 20-22 and 24-25, respectively, during the normal growth period. Outside the range delineates a syndrome or abnormality. CONCLUSIONS: The present study has generated metric norms for all growing ages and also the growth dynamics for ocular dimensions of healthy Indian subjects. The knowledge will be useful to physicians as a guideline in correcting ocular deformity. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Estimation of stature from hand impression: a nonconventional approach.

Stature is used for constructing a biological profile that assists with the identification of an individual. So far, little attention has been paid to the fact that stature can be estimated from hand impressions left at scene of crime. The present study based on practical observations adopted a new methodology of measuring hand length from the depressed area between hypothenar and thenar region on the proximal surface of the palm. Stature and bilateral hand impressions were obtained from 503 men of central India. Seventeen dimensions of hand were measured on the impression. Linear regression equations derived showed hand length followed by palm length are best estimates of stature. Testing the practical utility of the suggested method on latent prints of 137 subjects, a statistically insignificant result was obtained when known and estimated stature derived from latent prints was compared. The suggested approach points to a strong possibility of its usage in crime scene investigation, albeit the fact that validation studies in real-life scenarios are performed.

Growth of cranial volume: an anthropometric study.

The aim of the study is to follow the growth dynamics of cranial volume from birth to 18 years of age among 1623 central Indian subjects. Anthropometric technique was adopted to estimate the cranial volume using maximum length, width and auricular height of head. The mean cranial volume at birth is 376 cc in male and 308 cc in female i.e. 28% and 26% of the 18 years old volume. Within a year the volume reaches 65% in male and 59% in female of the adult size due to very rapid growth during the first six months after birth. The adult cranial volume at 18 years is 1329 cc in males and 1193 cc in females, approximately 3.5 and 4 times of the birth size respectively. The cranial volume reaches its adult size in females at 16 years of age and a year later in males. The present study has generated metrical norms for all growing ages and also the growth dynamics for cranial volume of Indian subjects which will be useful to physicians as a guideline in correcting cranial deformity.

A test of individuality of human external ear pattern: its application in the field of personal identification.

A preliminary study has been undertaken to test the individuality of human ear patterns and its probable use in profile view facial image recognition. Anthropometric measurements on 12 inter-landmark linear distances have been carried out for both left and right ears of 700 male and female individuals. A 12-dimensional feature space has been framed to represent each ear pattern as a feature vector with the measured inter-landmark distances as its components. The Euclidean distances in such a feature space amongst all possible pairs of ear patterns of both male and female individuals have been computed. Very few pairs have distances which fell below the safe distinction limit. The undistinguished pairs were further examined by direct superimposition of their images. None of the ear patterns is found to be exactly the same in morphology to the other. Even the left and right ears of the same individual are not identical. Thus, the present study reconfirms the individuality of ear patterns. For establishment of identity, a questioned profile view facial image can be compared with a control one on the basis of the ear pattern visible in it.

Anthropometry of the normal human auricle: a study of adult Indian men.

BACKGROUND: To treat auricular deformities or to perform facial rejuvenation, a plastic surgeon requires normative data for auricular dimensions. The metric standards vary in various ethnic groups, and such data are especially scarce from in India. This study aimed to provide anthropometric information about the normal dimensions of the adult male auricle in central India. METHODS: A cross-sectional study was undertaken in central India with 415 males categorized in five age groups. Six linear dimensions including the length and width of the auricle, lobule, and concha and the heights of the auricular protrusion at the superaurale and tragal levels were measured. Auricular, lobular, and conchal indices were calculated. The inclination of the auricle relative to its vertical axis was measured. Descriptions of various auricle parts including its shape, preauricular area, form of the helical fold, lobular shape, size, and type of attachment to the cheek were recorded. RESULTS: Almost all the linear measurements showed a steady increase in size with age. The dimensions of the lobule were dependent on its shape and attachment to the cheek. The mean lobular and auricular indices were found to decrease with increasing age, indicating more elongation than widening of the structures. On the average, bilateral asymmetry was observed in all measurements, although only auricular length, width, and conchal length in a few age groups were found to be statistically significant. The frequency distribution of forms of various auricular features is presented. CONCLUSION: The human ear continues to grow throughout life. The lobule contributes the most to the overall elongation of the auricle. This study furnishes the first set of metric data of auricular dimensions for normal Indian males 18 to 70 years of age. In comparison with other ethnic groups, Indian males seem to have the smallest auricular and lobular lengths, although their respective widths are comparable with those of others.

Triangle identified at the proximal end of femur: a new sex determinant.

Deviating from the conventional measurements, the present study uses the points of traction epiphysis on the upper end the femur as a landmark for measurement. A triangle was drawn on the posterior aspect of the femur using the apex of two traction epiphyses and the lateral most point on the articular margin of head. The study was conducted on 200 male and 80 female femora belonging to Central India. The lengths of triangle, so drawn, yielded highly significant results. The measurements were further evaluated by discriminant function analysis. Employing a single variable attained a prediction accuracy of 85.5% for males and 81.3% for females. When the variables were combined into a function, the accuracy improved to 86.5% for males and 86.3% for females. One of the advantages of the measurements on the proximal end of femur is that they can be used on fragmented bone where the shaft and distal end are missing. The study has applied value in the field of forensic anthropology.

A study of sexual variation in Indian femur.

Assessment of sex from femoral dimensions have been tried before in several populations. Studies conducted so far have demonstrated that populations differ from one another in size and proportion. Therefore, the discriminant formulae developed for determining sex for one population group cannot be applied on another. As to date no detailed study of femur on the subject has been reported from India, an attempt has been made in the present study to examine the sexual dimorphism in femur of Indian origin using 124 femora from central India. Eleven standard dimensions were measured on the bones. The data were analysed using discriminant function procedures and the results of different measurements are reported independently and in various combinations. Maximum head diameter alone could correctly assign sex to 92.5% of males and 95.5% of females. Evaluation of the discriminating ability of the variables selected in stepwise analysis are then conducted using cross validation procedure. To understand the population variation, the discriminant formula derived from Thai, Chinese, South African white, American black and white were applied on the present sample. The comparison indicated that Indians have very different dimension from South African whites and American whites. Their dimensions are more closer to Thais and Chinese but in no way identical to them.

Sex determination from femoral head measurements: a new approach.

Attempts to update techniques of sex determination are always made by the researchers in the field. One such study is presented on the femur head. The method has not so far been used. Two basic ingredients have been postulated on which the study is based. One is that the 'eye judgment' has been found to be redundant and produce faulty results. The second is that all measurements are taken in anatomical position and thereafter anatomical landmarks are identified for better comparable reproducibility. The study was conducted on 280 adult femora of known age, race and sex from a collection at the Medicolegal Institute, in central India. Four measurements were taken that were subjected to SPSS discriminant function analysis. An index was also calculated. Results indicated maximum vertical and horizontal diameter as best single discriminators each attaining accuracy of 92.1%.