Displaying publications 1 - 20 of 27 in total

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  1. Hadi H, Wilkinson CM
    Forensic Sci Int, 2014 Apr;237:149.e1-149.e7.
    PMID: 24613011 DOI: 10.1016/j.forsciint.2013.12.014
    The post-mortem resilience of facial creases was studied using donated bodies in order to establish the efficacy of crease analysis for identification of the dead. Creases were studied on normal (pre-embalmed) and bloated (embalmed) cadavers at the Centre for Anatomy and Human Identification (CAHID) to establish whether facial bloating would affect facial crease visibility. Embalming was chosen to simulate the effects produced by post-mortem bloating. The results suggested that creases are resilient and changes were only detected for creases located on the periphery of the face, particularly at areas where the skin is thick, such as at the cheeks. Two new creases not previously classified were identified; these creases were called the vertical superciliary arch line and the lateral nose crease. This research suggests that facial creases may be resilient enough after death to be utilised for human identification.
    Matched MeSH terms: Face/anatomy & histology*
  2. Hadi H, Wilkinson CM
    J Cosmet Dermatol, 2017 Jun;16(2):180-185.
    PMID: 28145033 DOI: 10.1111/jocd.12305
    Ensuring uniformity in the nomenclature standardization of facial creases is important to enable the scholarly community to follow and debate the advancements in research. This review highlights the prevailing disparity in the nomenclature that refers to the same facial crease by researchers and laypeople, and suggests uniform names for the facial creases based on available literature. The previous and current trends in facial crease classification are also discussed. The nomenclature of the facial creases considered for this review include the following: the nasolabial fold, corner of the mouth lines, upper and lower lip creases around the mouth region, the mandibular folds, the bifid nose, the transverse nasal line, the vertical glabellar line, chin crease, the mental crease, four type of creases around the eyes, forehead creases, and periauricular creases. A figure illustrating the above facial creases is included as reference. It is hoped that the proposed standardization of nomenclature would ensure a more scientific referencing of facial creases enabling more effective scientific interaction among the scholarly community as well as the laypeople interested in the research and application of facial creases.
    Matched MeSH terms: Face/anatomy & histology*
  3. Jayaprakash PT
    Forensic Sci Int, 2015 Jan;246:110-21.
    PMID: 25498986 DOI: 10.1016/j.forsciint.2014.10.043
    Establishing identification during skull-photo superimposition relies on correlating the salient morphological features of an unidentified skull with those of a face-image of a suspected dead individual using image overlay processes. Technical progression in the process of overlay has included the incorporation of video cameras, image-mixing devices and software that enables real-time vision-mixing. Conceptual transitions occur in the superimposition methods that involve 'life-size' images, that achieve orientation of the skull to the posture of the face in the photograph and that assess the extent of match. A recent report on the reliability of identification using the superimposition method adopted the currently prevalent methods and suggested an increased rate of failures when skulls were compared with related and unrelated face images. The reported reduction in the reliability of the superimposition method prompted a review of the transition in the concepts that are involved in skull-photo superimposition. The prevalent popular methods for visualizing the superimposed images at less than 'life-size', overlaying skull-face images by relying on the cranial and facial landmarks in the frontal plane when orienting the skull for matching and evaluating the match on a morphological basis by relying on mix-mode alone are the major departures in the methodology that may have reduced the identification reliability. The need to reassess the reliability of the method that incorporates the concepts which have been considered appropriate by the practitioners is stressed.
    Matched MeSH terms: Face/anatomy & histology*
  4. Ibáñez O, Valsecchi A, Cavalli F, Huete MI, Campomanes-Alvarez BR, Campomanes-Alvarez C, et al.
    Leg Med (Tokyo), 2016 Nov;23:59-70.
    PMID: 27890106 DOI: 10.1016/j.legalmed.2016.09.009
    Craniofacial superimposition has the potential to be used as an identification method when other traditional biological techniques are not applicable due to insufficient quality or absence of ante-mortem and post-mortem data. Despite having been used in many countries as a method of inclusion and exclusion for over a century it lacks standards. Thus, the purpose of this research is to provide forensic practitioners with standard criteria for analysing skull-face relationships. Thirty-seven experts from 16 different institutions participated in this study, which consisted of evaluating 65 criteria for assessing skull-face anatomical consistency on a sample of 24 different skull-face superimpositions. An unbiased statistical analysis established the most objective and discriminative criteria. Results did not show strong associations, however, important insights to address lack of standards were provided. In addition, a novel methodology for understanding and standardizing identification methods based on the observation of morphological patterns has been proposed.
    Matched MeSH terms: Face/anatomy & histology*
  5. Oettlé AC, Demeter FP, L'abbé EN
    Anat Rec (Hoboken), 2017 01;300(1):196-208.
    PMID: 28000408 DOI: 10.1002/ar.23469
    The variable development of the zygoma, dictating its shape and size variations among ancestral groups, has important clinical implications and valuable anthropological and evolutionary inferences. The purpose of the study was to review the literature regarding the variations in the zygoma with ancestry. Ancestral variation in the zygoma reflects genetic variations because of genetic drift as well as natural selection and epigenetic changes to adapt to diet and climate variations with possible intensification by isolation. Prominence of the zygoma, zygomaxillary tuberosity, and malar tubercle have been associated with Eastern Asian populations in whom these features intensified. Prominence of the zygoma is also associated with groups from Eastern Europe and the rest of Asia. Diffusion of these traits occurred across the Behring Sea to the Arctic areas and to North and South America. The greatest zygomatic projections are exhibited in Arctic groups as an adaptation to extreme cold conditions, while Native South American groups also present with other features of facial robusticity. Groups from Australia, Malaysia, and Oceania show prominence of the zygoma to a certain extent, possibly because of archaic occupations by undifferentiated Southeast Asian populations. More recent interactions with Chinese groups might explain the prominent cheekbones noted in certain South African groups. Many deductions regarding evolutionary processes and diversifications of early groups have been made. Cognisance of these ancestral variations also have implications for forensic anthropological assessments as well as plastic and reconstructive surgery. More studies are needed to improve accuracy of forensic anthropological identification techniques. Anat Rec, 300:196-208, 2017. © 2016 Wiley Periodicals, Inc.
    Matched MeSH terms: Face/anatomy & histology*
  6. Tan SK, Leung WK, Tang ATH, Zwahlen RA
    Am J Orthod Dentofacial Orthop, 2022 Feb;161(2):e105-e113.
    PMID: 34531091 DOI: 10.1016/j.ajodo.2021.01.024
    INTRODUCTION: This study was conducted to investigate and compare esthetic perceptions of different facial profiles among Hong Kong Chinese laypersons and patients scheduled for orthognathic treatment.

    METHODS: Two sets of 3-dimensional facial photographs (1 male and 1 female) each comprised 7 images that showed different dentoskeletal relations (ie, Class I, bimaxillary protrusion, bimaxillary retrusion, maxillary protrusion, maxillary retrusion, mandibular protrusion, and mandibular retrusion). The sets of photographs were shown to 101 laypersons (age, 28.87 ± 6.22 years) and 60 patients seeking orthognathic treatment (age, 27.12 ± 6.07 years). They rated their esthetic perceptions of the photographs on the basis of a 100 mm visual analog scale (VAS) from 0 (very unattractive) to 100 (very attractive).

    RESULTS: The dentoskeletal Class I facial profile was ranked as the most attractive profile. Female orthognathic judges selected the retrusive maxilla while male orthognathic judges and male and female laypersons ranked the mandibular protrusion profile as the least attractive profile for both females and males. A bimaxillary protrusive female profile was viewed as more attractive by the orthognathic male (P = 0.006) and female (P = 0.006) judges, compared with female layperson judges. After adjustment for age, no statistically significant interaction between sex and judges (P >0.10) for all VAS scores were detected. For the female bimaxillary protrusive profile, orthognathic patient judges assigned a mean VAS score of 9.174 points higher than layperson judges (95% confidence interval, 3.11-15.24; P = 0.003).

    CONCLUSION: Dentoskeletal Class I facial profile was generally considered the most attractive profile in both sexes; male and female orthognathic patients preferred a bimaxillary protrusive female profile. A concave facial profile was perceived as least attractive in both sexes.

    Matched MeSH terms: Face/anatomy & histology
  7. Al-Khatib AR, Rajion ZA, Masudi SM, Hassan R, Townsend GC
    Homo, 2013 Aug;64(4):296-311.
    PMID: 23755965 DOI: 10.1016/j.jchb.2013.04.002
    The aim of this study was to evaluate the relationships of selected facial measurements with mesio-distal crown widths and dental arch dimensions in individuals with normal occlusions. A cross-sectional study was conducted on 276 subjects with Angle's Class I normal occlusions. Three-dimensional images of the face and dental casts were captured and analyzed using stereophotogrammetric systems. Significant correlations were found between the sagittal facial variables and both upper and lower dental arch dimensions and to lesser degree with the horizontal and vertical variables. The values of correlation coefficients calculated between facial and dental crown measurements ranged from .01 to .50 for upper teeth and .01 to .49 for lower teeth. The values of correlation coefficients between facial and upper dental arch dimensions ranged from .01 to .55 and those between facial and lower dental arch dimensions ranged from .01 to .60. A principal components analysis showed that the sagittal dimensions, face height, nose, labial fissure, binocular widths were positively associated with dental arch dimensions and mesio-distal crown diameters in males. On the other hand, only the sagittal variables were associated with dental dimensions in females. The results of this study confirm that positive associations exist between facial and dental arch dimensions. These relationships should be taken into consideration when attempts are made to modify dental arch size as part of orthodontic treatment. Moreover, these relationships are also relevant to prosthodontists involved with selecting tooth sizes that display optimal functional balance with the craniofacial structures.
    Matched MeSH terms: Face/anatomy & histology*
  8. Ngeow WC, Aljunid ST
    Singapore Med J, 2009 May;50(5):525-8.
    PMID: 19495526
    INTRODUCTION: This study was undertaken to establish the craniofacial anthropometric norms of young adult Malaysian Malays.
    METHODS: The study group consisted of convenient samples of 100 healthy volunteers (aged 18-25 years), with an equal number of female and male subjects who had no history of mixed racial parentage. 22 linear measurements were taken twice from 22 landmarks over six craniofacial regions.
    RESULTS: The Malays shared many similar sizes of measurements with the Singaporean Chinese. Their left eye fissure length and mouth width (ch-ch) were almost identical for both genders. However, Malay females had an upper lip height (sn-sto) (left) and ear width (pra-pa) similar to Singaporean Chinese females. Six other measurements, viz. the head width (eu-eu), head circumference (on-op), face height (n-gn), lower face height (sn-gn), (left) eye fissure height (ps-pi), cutaneous upper lip height (sn-ls) and cutaneous upper lip height (ls-sto), were 0.4-4.3 mm less in the Malays. Measurements for another four parameters, viz. the length of the head (g-op), biocular width (ex-ex), lower vermillion height (sto-li) and (left) ear length (sa-sba), were 0.5-3.6 mm higher in the Malays. Only three measurements were obviously different; the height of the head (v-n) and intercanthal width (en-en), were lower, and the protrusion of the nasal tip (sn-prn) was higher in the Malays.
    CONCLUSION: These findings suggest that three features, i.e. the height of the head (v-n), intercanthal width (en-en) and protrusion of the nasal tip (sn-prn) may be useful in differentiating a Malay face from a Singaporean Chinese one.
    Matched MeSH terms: Face/anatomy & histology*
  9. Teoh AB, Goh A, Ngo DC
    IEEE Trans Pattern Anal Mach Intell, 2006 Dec;28(12):1892-901.
    PMID: 17108365
    Biometric analysis for identity verification is becoming a widespread reality. Such implementations necessitate large-scale capture and storage of biometric data, which raises serious issues in terms of data privacy and (if such data is compromised) identity theft. These problems stem from the essential permanence of biometric data, which (unlike secret passwords or physical tokens) cannot be refreshed or reissued if compromised. Our previously presented biometric-hash framework prescribes the integration of external (password or token-derived) randomness with user-specific biometrics, resulting in bitstring outputs with security characteristics (i.e., noninvertibility) comparable to cryptographic ciphers or hashes. The resultant BioHashes are hence cancellable, i.e., straightforwardly revoked and reissued (via refreshed password or reissued token) if compromised. BioHashing furthermore enhances recognition effectiveness, which is explained in this paper as arising from the Random Multispace Quantization (RMQ) of biometric and external random inputs.
    Matched MeSH terms: Face/anatomy & histology*
  10. Kuze N, Malim TP, Kohshima S
    Am J Primatol, 2005 Apr;65(4):353-76.
    PMID: 15834889
    Orangutans display remarkable developmental changes and sexual differences in facial morphology, such as the flanges or cheek-pads that develop only on the face of dominant adult males. These changes suggest that facial morphology is an important factor in visual communication. However, developmental changes in facial morphology have not been examined in detail. We studied developmental changes in the facial morphology of the Borneo orangutan (Pongo pygmaeus) by observing 79 individuals of various ages living in the Sepilok Orangutan Rehabilitation Centre (SORC) in Malaysia and in Japanese zoos. We also analyzed photographs of one captive male that were taken over a period of more than 16 years. There were clear morphological changes that occurred with growth, and we identified previously unreported sexual and developmental differences in facial morphology. Light-colored skin around the eyes and mouth is most prominent in animals younger than 3 years, and rapidly decreases in area through the age of approximately 7 years. At the same time, the scattered, erect hairs on the head (infant hair) become thick, dense hairs lying on the head (adult hair) in both sexes. The results suggest that these features are infant signals, and that adult signals may include darkened face color, adult hair, whiskers, and a beard, which begin to develop after the age of approximately 7 years in both sexes. In females, the eyelids remain white even after 10 years, and turn black at around the age of 20; in males, the eyelids turn black before the age of 10. The whiskers and beards of adults are thicker in males than in females, and are fully developed before the age of 10 in males, while they begin to develop in females only after approximately 20 years. White eyelids and undeveloped whiskers and beards may be visual signals that are indicative of young adult females. Our results also show that the facial morphology of the unflanged male is similar to that of the adult female, although it has also been pointed out that unflanged males resemble younger individuals.
    Matched MeSH terms: Face/anatomy & histology*
  11. Damas S, Wilkinson C, Kahana T, Veselovskaya E, Abramov A, Jankauskas R, et al.
    Forensic Sci Int, 2015 Dec;257:504-508.
    PMID: 26482539 DOI: 10.1016/j.forsciint.2015.07.045
    Craniofacial superimposition, although existing for one century, is still a controversial technique within the scientific community. Objective and unbiased validation studies over a significant number of cases are required to establish a more solid picture on the reliability. However, there is lack of protocols and standards in the application of the technique leading to contradictory information concerning reliability. Instead of following a uniform methodology, every expert tends to apply his own approach to the problem, based on the available technology and deep knowledge on human craniofacial anatomy, soft tissues, and their relationships. The aim of this study was to assess the reliability of different craniofacial superimposition methodologies and the corresponding technical approaches to this type of identification. With all the data generated, some of the most representative experts in craniofacial identification joined in a discussion intended to identify and agree on the most important issues that have to be considered to properly employ the craniofacial superimposition technique. As a consequence, the consortium has produced the current manuscript, which can be considered the first standard in the field; including good and bad practices, sources of error and uncertainties, technological requirements and desirable features, and finally a common scale for the craniofacial matching evaluation. Such a document is intended to be part of a more complete framework for craniofacial superimposition, to be developed during the FP7-founded project MEPROCS, which will favour and standardize its proper application.
    Matched MeSH terms: Face/anatomy & histology*
  12. Ibáñez O, Vicente R, Navega DS, Wilkinson C, Jayaprakash PT, Huete MI, et al.
    Forensic Sci Int, 2015 Dec;257:496-503.
    PMID: 26060056 DOI: 10.1016/j.forsciint.2015.05.030
    As part of the scientific tasks coordinated throughout The 'New Methodologies and Protocols of Forensic Identification by Craniofacial Superimposition (MEPROCS)' project, the current study aims to analyse the performance of a diverse set of CFS methodologies and the corresponding technical approaches when dealing with a common dataset of real-world cases. Thus, a multiple-lab study on craniofacial superimposition has been carried out for the first time. In particular, 26 participants from 17 different institutions in 13 countries were asked to deal with 14 identification scenarios, some of them involving the comparison of multiple candidates and unknown skulls. In total, 60 craniofacial superimposition problems divided in two set of females and males. Each participant follow her/his own methodology and employed her/his particular technological means. For each single case they were asked to report the final identification decision (either positive or negative) along with the rationale supporting the decision and at least one image illustrating the overlay/superimposition outcome. This study is expected to provide important insights to better understand the most convenient characteristics of every method included in this study.
    Matched MeSH terms: Face/anatomy & histology*
  13. Jayaprakash PT, Hashim N, Yusop RA
    Forensic Sci Int, 2015 Aug;253:131.e1-10.
    PMID: 26103927 DOI: 10.1016/j.forsciint.2015.04.026
    Video vision mixer based skull-photo superimposition is a popular method for identifying skulls retrieved from unidentified human remains. A report on the reliability of the superimposition method suggested increased failure rates of 17.3 to 32% to exclude and 15 to 20% to include skulls while using related and unrelated face photographs. Such raise in failures prompted an analysis of the methods employed for the research. The protocols adopted for assessing the reliability are seen to vary from those suggested by the practitioners in the field. The former include overlaying the skull- and face-images on the basis of morphology by relying on anthropometric landmarks on the front plane of the face-images and evaluating the goodness of match depending on mix-mode images; the latter consist of orienting the skull considering landmarks on both the eye and ear planes of the face- and skull-images and evaluating the match utilizing images seen in wipe-mode in addition to those in mix-mode. Superimposition of a skull with face-images of five living individuals in two sets of experiments, one following the procedure described for the research on reliability and the other applying the methods suggested by the practitioners has shown that overlaying the images on the basis of morphology depending on the landmarks on the front plane alone and assessing the match in mix-mode fails to exclude the skull. However, orienting the skull relying on the relationship between the anatomical landmarks on the skull- and face-images such as Whitnall's tubercle and exocanthus in the front (eye) plane and the porion and tragus in the rear (ear) plane as well as assessing the match using wipe-mode images enables excluding that skull while superimposing with the same set of face-images.
    Matched MeSH terms: Face/anatomy & histology*
  14. Lew KK
    Asian J Aesthet Dent, 1994;2(1):35-8.
    PMID: 9063112
    Cephalometric data from 105 female subjects (35 Chinese, 35 Malay and 35 Indian) with good occlusion and aesthetic pleasing facial profiles (determined by a trained clinician and endorsed by the lay public) were analysed using the Steiner analysis. Statistical analysis of the data showed that while the cephalometric ideals of the Chinese and the Malay ethnic groups were rather similar, cephalometric differences existed between the Chinese and Indians as well as the Malays and Indians. Compared to the Chinese and Malays, the Indians appeared to have less prognathic mandibles and maxillae, less protrusive and proclined upper and lower incisors and also less protrusive upper and lower lips. These differences demonstrate intrinsic ethnic differences and emphasize the need to treat patients of different ethnic groups using cephalometric norms which are peculiar to their own group.
    Matched MeSH terms: Face/anatomy & histology*
  15. Jayaprakash PT
    Forensic Sci Int, 2017 Sep;278:411.e1-411.e8.
    PMID: 28754256 DOI: 10.1016/j.forsciint.2017.04.021
    Often cited reliability test on video superimposition method integrated scaling face-images in relation to skull-images, tragus-auditory meatus relationship in addition to exocanthion-Whitnall's tubercle relationship when orientating the skull-image and wipe mode imaging in addition to mix mode imaging when obtaining skull-face image overlay and evaluating the goodness of match. However, a report that found higher false positive matches in computer assisted superimposition method transited from the above foundational concepts and relied on images of unspecified sizes that are lesser than 'life-size', frontal plane landmarks in the skull- and face- images alone for orientating the skull-image and mix images alone for evaluating the goodness of match. Recently, arguing the use of 'life-size' images as 'archaic', the authors who tested the reliability in the computer assisted superimposition method have denied any method transition. This article describes that the use of images of unspecified sizes at lesser than 'life-size' eliminates the only possibility to quantify parameters during superimposition which alone enables dynamic skull orientation when overlaying a skull-image with a face-image in an anatomically acceptable orientation. The dynamic skull orientation process mandatorily requires aligning the tragus in the 2D face-image with the auditory meatus in the 3D skull-image for anatomically orientating the skull-image in relation to the posture in the face-image, a step not mentioned by the authors describing the computer assisted superimposition method. Furthermore, mere reliance on mix type images during image overlay eliminates the possibility to assess the relationship between the leading edges of the skull- and face-image outlines as also specific area match among the corresponding craniofacial organs during superimposition. Indicating the possibility of increased false positive matches as a consequence of the above method transitions, the need for testing the reliability in the superimposition method adopting concepts that are considered safe is stressed.
    Matched MeSH terms: Face/anatomy & histology*
  16. Nimbalkar S, Oh YY, Mok RY, Tioh JY, Yew KJ, Patil PG
    J Prosthet Dent, 2018 Aug;120(2):252-256.
    PMID: 29551374 DOI: 10.1016/j.prosdent.2017.10.021
    STATEMENT OF PROBLEM: Buccal corridor space and its variations greatly influence smile attractiveness. Facial types are different for different ethnic populations, and so is smile attractiveness. The subjective perception of smile attractiveness of different populations may vary in regard to different buccal corridor spaces and facial patterns.

    PURPOSE: The purpose of this study was to determine esthetic perceptions of the Malaysian population regarding the width of buccal corridor spaces and their effect on smile esthetics in individuals with short, normal, and long faces.

    MATERIAL AND METHODS: The image of a smiling individual with a mesofacial face was modified to create 2 different facial types (brachyfacial and dolicofacial). Each face form was further modified into 5 different buccal corridors (2%, 10%, 15%, 22%, and 28%). The images were submitted to 3 different ethnic groups of evaluators (Chinese, Malay, Indian; 100 each), ranging between 17 and 21 years of age. A visual analog scale (50 mm in length) was used for assessment. The scores given to each image were compared with the Kruskal-Wallis test, and pairwise comparison was performed using the Mann-Whitney U test (α=.05).

    RESULTS: All 3 groups of evaluators could distinguish gradations of dark spaces in the buccal corridor at 2%, 10%, and 28%. Statistically significant differences were observed among 3 groups of evaluators in esthetic perception when pairwise comparisons were performed. A 15% buccal corridor was found to score esthetically equally within 3 face types by all 3 groups of evaluators. The Indian population was more critical in evaluation than the Chinese or Malay populations. In a pairwise comparison, more significant differences were found between long and short faces and the normal face; the normal face was compared with long and short faces separately.

    CONCLUSIONS: The width of the buccal corridor space influences smile attractiveness in different facial types. A medium buccal corridor (15%) is the esthetic characteristic preferred by all groups of evaluators in short, normal, and long face types.

    Matched MeSH terms: Face/anatomy & histology*
  17. Abu A, Ngo CG, Abu-Hassan NIA, Othman SA
    BMC Bioinformatics, 2019 Feb 04;19(Suppl 13):548.
    PMID: 30717658 DOI: 10.1186/s12859-018-2548-9
    BACKGROUND: Indirect anthropometry (IA) is one of the craniofacial anthropometry methods to perform the measurements on the digital facial images. In order to get the linear measurements, a few definable points on the structures of individual facial images have to be plotted as landmark points. Currently, most anthropometric studies use landmark points that are manually plotted on a 3D facial image by the examiner. This method is time-consuming and leads to human biases, which will vary from intra-examiners to inter-examiners when involving large data sets. Biased judgment also leads to a wider gap in measurement error. Thus, this work aims to automate the process of landmarks detection to help in enhancing the accuracy of measurement. In this work, automated craniofacial landmarks (ACL) on a 3D facial image system was developed using geometry characteristics information to identify the nasion (n), pronasale (prn), subnasale (sn), alare (al), labiale superius (ls), stomion (sto), labiale inferius (li), and chelion (ch). These landmarks were detected on the 3D facial image in .obj file format. The IA was also performed by manually plotting the craniofacial landmarks using Mirror software. In both methods, once all landmarks were detected, the eight linear measurements were then extracted. Paired t-test was performed to check the validity of ACL (i) between the subjects and (ii) between the two methods, by comparing the linear measurements extracted from both ACL and AI. The tests were performed on 60 subjects (30 males and 30 females).

    RESULTS: The results on the validity of the ACL against IA between the subjects show accurate detection of n, sn, prn, sto, ls and li landmarks. The paired t-test showed that the seven linear measurements were statistically significant when p 

    Matched MeSH terms: Face/anatomy & histology*
  18. Agbolade O, Nazri A, Yaakob R, Ghani AA, Cheah YK
    PLoS One, 2020;15(4):e0228402.
    PMID: 32271782 DOI: 10.1371/journal.pone.0228402
    BACKGROUND: The application of three-dimensional scan models offers a useful resource for studying craniofacial variation. The complex mathematical analysis for facial point acquisition in three-dimensional models has made many craniofacial assessments laborious.

    METHOD: This study investigates three-dimensional (3D) soft-tissue craniofacial variation, with relation to ethnicity, sex and age variables in British and Irish white Europeans. This utilizes a geometric morphometric approach on a subsampled dataset comprising 292 scans, taken from a Liverpool-York Head Model database. Shape variation and analysis of each variable are tested using 20 anchor anatomical landmarks and 480 sliding semi-landmarks.

    RESULTS: Significant ethnicity, sex, and age differences are observed for measurement covering major aspects of the craniofacial shape. The ethnicity shows subtle significant differences compared to sex and age; even though it presents the lowest classification accuracy. The magnitude of dimorphism in sex is revealed in the facial, nasal and crania measurement. Significant shape differences are also seen at each age group, with some distinct dimorphic features present in the age groups.

    CONCLUSIONS: The patterns of shape variation show that white British individuals have a more rounded head shape, whereas white Irish individuals have a narrower head shape. White British persons also demonstrate higher classification accuracy. Regarding sex patterns, males are relatively larger than females, especially in the mouth and nasal regions. Females presented with higher classification accuracy than males. The differences in the chin, mouth, nose, crania, and forehead emerge from different growth rates between the groups. Classification accuracy is best for children and senior adult age groups.

    Matched MeSH terms: Face/anatomy & histology*
  19. Nazri A, Agbolade O, Yaakob R, Ghani AA, Cheah YK
    BMC Bioinformatics, 2020 May 24;21(1):208.
    PMID: 32448182 DOI: 10.1186/s12859-020-3497-7
    BACKGROUND: Landmark-based approaches of two- or three-dimensional coordinates are the most widely used in geometric morphometrics (GM). As human face hosts the organs that act as the central interface for identification, more landmarks are needed to characterize biological shape variation. Because the use of few anatomical landmarks may not be sufficient for variability of some biological patterns and form, sliding semi-landmarks are required to quantify complex shape.

    RESULTS: This study investigates the effect of iterations in sliding semi-landmarks and their results on the predictive ability in GM analyses of soft-tissue in 3D human face. Principal Component Analysis (PCA) is used for feature selection and the gender are predicted using Linear Discriminant Analysis (LDA) to test the effect of each relaxation state. The results show that the classification accuracy is affected by the number of iterations but not in progressive pattern. Also, there is stability at 12 relaxation state with highest accuracy of 96.43% and an unchanging decline after the 12 relaxation state.

    CONCLUSIONS: The results indicate that there is a particular number of iteration or cycle where the sliding becomes optimally relaxed. This means the higher the number of iterations is not necessarily the higher the accuracy.

    Matched MeSH terms: Face/anatomy & histology*
  20. Albajalan OB, Samsudin AR, Hassan R
    Eur J Orthod, 2011 Oct;33(5):509-14.
    PMID: 21118908 DOI: 10.1093/ejo/cjq108
    The aim of this study was to compare the skeletal and soft tissue patterns between obstructive sleep apnoea (OSA) patients and control group of non-OSA patients. Fifty Malays (32 males and 18 females) aged 18-65 years divided into two equal groups 25 (17 males and 8 females) with OSA and a control group 25 subjects (15 males and 10 females). Both groups were diagnosed using polysomnography. Nineteen variables related to craniofacial skeletal and soft tissue morphology were measured on lateral cephalometric films. Analysis of covariance was used to compare the means between the two groups. The results showed that OSA subjects had a significant increase in body mass index (BMI) and neck circumference than the control group. The soft palate and tongue were longer and thicker in OSA patients. In addition, upper, middle, and lower posterior airway spaces were narrower, the hyoid bone was more inferior and posterior, and the cranial base flexure angle was significantly acute when compared with the control group. The findings indicate that craniofacial abnormalities play significant roles in the pathogenesis of OSA in Malay patients.
    Matched MeSH terms: Face/anatomy & histology
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