Developmental craniofacial anthropometry: Assessment of race effects

Anthropometric Analysis of Indian Faces: A Systematic Review

Objective

Facial anthropometric data vary significantly within the Indian population due to the racial, ethnic and geographic diversity. The anthropometric data of a given ethnic community may not match the other due to diverse ethnic variations, and hence, this study is intended to review the facial anthropometric data pertaining to the diverse Indian populace through a systematic literature survey.

Materials and Method

An electronic search done on Medline, Embase and Central databases was utilized to conduct a systematic review of literature. The available data were analyzed based on the various esthetic subunits of the face. The following inclusion criteria were considered: (1) studies depicting the anthropometric data of any ethnic group identified as belonging to India, (2) studies originating from Indian subcontinent, (3) studies which included data of male and female subjects separately and (4) articles in English language only. The following exclusion criteria were considered: (1) atudies conducted on participants with severe malocclusion, developmental craniofacial anomalies, post-traumatic facial deformities or with a history of previous craniofacial or cosmetic surgery, (2) studies which did not specify the anthropometric landmarks used to obtain the measurements, (3) studies in which the statistical analysis was not provided, or if data were grouped across genders and (4) editorials, commentaries, case reports, systematic reviews, meta-analyses and articles not available in English language.

Results

Twenty-one articles met the inclusion criteria. Majority of the Indians, particularly men, seem to have a mesoproscopic facial phenotype. The vertical and horizontal facial dimensions of the Indian male are comparably larger than the Indian female. There is sexual dimorphism among the Indian population with regard to the upper and lower thirds of the face, with little or no gender difference as regards the middle third of the face. It was observed that the nasal dimensions of the Indian race were not compatible with that of the occidental, oriental or the western race. The overall facial structure and the upper half of the face were critical in determining facial attractiveness in Indian males while the lower half of the face and the mandibular contour were critical in determining facial attractiveness in females.

Conclusion

It is observed that there is a paucity of facial anthropometric data for the Indian population considering the ethnic, racial and geographic diversity. Since the prevalence of craniofacial anomalies and dentofacial deformities in India is high and thus the scope for corrective surgery, it is important to compile baseline facial anthropometric data based on the ethnic diversity of the Indian population.

Anatomic development of the upper airway during the first five years of life: A three-dimensional imaging study

PURPOSE

Normative data on the growth and development of the upper airway across the sexes is needed for the diagnosis and treatment of congenital and acquired respiratory anomalies and to gain insight on developmental changes in speech acoustics and disorders with craniofacial anomalies.

METHODS

The growth of the upper airway in children ages birth to 5 years, as compared to adults, was quantified using an imaging database with computed tomography studies from typically developing individuals. Methodological criteria for scan inclusion and airway measurements included: head position, histogram-based airway segmentation, anatomic landmark placement, and development of a semi-automatic centerline for data extraction. A comprehensive set of 2D and 3D supra- and sub-glottal measurements from the choanae to tracheal opening were obtained including: naso-oro-laryngo-pharynx subregion volume and length, each subregion's superior and inferior cross-sectional-area, and antero-posterior and transverse/width distances.

RESULTS

Growth of the upper airway during the first 5 years of life was more pronounced in the vertical and transverse/lateral dimensions than in the antero-posterior dimension. By age 5 years, females have larger pharyngeal measurement than males. Prepubertal sex-differences were identified in the subglottal region.

CONCLUSIONS

Our findings demonstrate the importance of studying the growth of the upper airway in 3D. As the lumen length increases, its shape changes, becoming increasingly elliptical during the first 5 years of life. This study also emphasizes the importance of methodological considerations for both image acquisition and data extraction, as well as the use of consistent anatomic structures in defining pharyngeal regions.

Growth and sexual dimorphism of the hyoid bone and its relationship to the mandible from birth to 19 years: A three-dimensional computed tomography study

The hyoid bone and the hyomandibular complex subserve the functions of respiration, deglutition, and speech. This study quantified the growth of the hyoid bone and the hyomandibular relationships in males and females from birth to 19 years. Using 97 computed tomography (CT) scans, from a previous study (Kelly et al., 2017) on mandibular growth from 49 individuals (16 with longitudinal scans), landmarks were placed on 3D CT models and used to calculate four distance, and three angular measurements. A general increase in growth trend was observed in hyoid bone linear measurements-length, width, and depth-as well as relational mandible-to-hyoid distance, throughout the developmental ages examined in both males and females, with most variables having larger measurements for females up to age 10 years. A general decrease in all three angular measurements was observed in both males and females up to approximately age 12 years, at which time male angular measurements gradually increased with significant sexual dimorphism emerging after age 15 years. As expected, postpubertal males had greater hyoid angle than females; they also had greater hyoid angle of inclination than mandible body inclination (with inclination relative to the anterior-posterior nasal plane), likely related to hyo-laryngeal descent. This study contributes to normative data on hyoid bone and hyomandibular relational growth in typically developing individuals and provides a baseline against which structural and functional influences on anatomic growth may be examined by clinical disciplines that address the aerodigestive and speech functions, as well as the fields of anatomy, forensics, and anthropology.

Craniofacial Anthropometric Profile of East Asians

Facial anthropometric data has significant ethnic variation. East Asia, comprised of fourteen countries, represents a significant proportion of the global population. This systematic review presents the facial anthropometric data collected from these countries. The systematic review was conducted in accordance with PRISMA guidelines. An electronic search of the MEDLINE database returned 3054 articles. Twenty articles were considered eligible for inclusion. Nine studies were conducted in China, 1 in Indonesia, 2 in Japan,3 in Korea, 4 in Malaysia, and 1 was a multicentre study conducted in China, Japan, Thailand, and Vietnam. Qualitative and quantitative parameters were extracted from the20 studies. No data was found for the other East Asian countries. There is a paucity of facial anthropometric data for East Asian countries despite their high burden of craniofacial anomalies and a strong demand for cosmetic facial surgery, both of which would benefit from the collection of robust craniofacial norms. It is in the interest of both the craniofacial surgeon and the East Asian patient to collect baseline facial anthropometric data for this population.

The South Asian facial anthropometric profile: A systematic review

PURPOSE

Craniofacial anatomy, as measured by facial anthropometric data, varies significantly between races. South Asia, comprised of eight countries, represents a large proportion of the global population and is the fastest-growing region of the world. This systematic review presents the facial anthropometric data collected for populations from this region.

MATERIALS AND METHODS

This systematic review was conducted in accordance with PRISMA guidelines. A systematic review of the literature was conducted by an electronic search of the MEDLINE and Cochran databases, returning 1675 articles. Bibliographies of accepted articles were screened to identify further eligible studies.

RESULTS

A total of 12 articles were considered eligible for the systematic review. Two studies were conducted in Bangladesh, 7 in India, and 3 in Nepal. No facial anthropometric data were found for populations from Afghanistan, Bhutan, Maldives, Pakistan, or Sri Lanka. Qualitative and quantitative parameters from the 12 studies were extracted.

CONCLUSION

There is a paucity of facial anthropometric data for South Asian populations. As South Asia has a significant prevalence of craniofacial anomalies and a burgeoning cosmetic facial surgery market, it is in the interest of both the craniofacial surgeon and the South Asian patient to collect baseline facial anthropometric data for this population.

Examining age, sex, and race characteristics of velopharyngeal structures in 4- to 9-year old children using magnetic resonance imaging

Objective

The purpose of this study was to quantify the growth of the various craniofacial and velopharyngeal structures and examine sex and race effects.

Methods

Eight-five healthy children (53 White and 32 Black) with normal velopharyngeal anatomy between 4 and 9 years of age who met the inclusion criteria and successfully completed the MRI scans were included in the study.

Results

Developmental normative mean values for selected craniometric and velopharyngeal variables by race and sex are reported. Cranial variables (face height, nasion to sella, sella to basion, palate height, palate width) and velopharyngeal variables (levator muscle length, angle of origin, sagittal angle, velar length, velar thickness, velar knee to posterior pharyngeal wall, and posterior nasal spine to levator muscle) demonstrated a trend toward a decrease in angle measures and increase in linear measures as age increased (with the exception of PNS to levator muscle). Only hard palate width and levator muscle length showed a significant sex effect. However, two cranial and six velopharyngeal variables showed a significant race effect. The interactions between sex, race, and age were not statistically significant across all variables, with the exception of posterior nasal spine to posterior pharyngeal wall.

Conclusion

Findings established a large age and race-specific normative reference for craniometiric and velopharyngeal variables. Data reveal minimal sexual dimorphism variables used in the present study; however, significant racial effects were observed.

Test-retest repeatability of human speech biomarkers from static and real-time dynamic magnetic resonance imaging

Static anatomical and real-time dynamic magnetic resonance imaging (RT-MRI) of the upper airway is a valuable method for studying speech production in research and clinical settings. The test-retest repeatability of quantitative imaging biomarkers is an important parameter, since it limits the effect sizes and intragroup differences that can be studied. Therefore, this study aims to present a framework for determining the test-retest repeatability of quantitative speech biomarkers from static MRI and RT-MRI, and apply the framework to healthy volunteers. Subjects (n = 8, 4 females, 4 males) are imaged in two scans on the same day, including static images and dynamic RT-MRI of speech tasks. The inter-study agreement is quantified using intraclass correlation coefficient (ICC) and mean within-subject standard deviation (σ_e). Inter-study agreement is strong to very strong for static measures (ICC: min/median/max 0.71/0.89/0.98, σ_e: 0.90/2.20/6.72 mm), poor to strong for dynamic RT-MRI measures of articulator motion range (ICC: 0.26/0.75/0.90, σ_e: 1.6/2.5/3.6 mm), and poor to very strong for velocities (ICC: 0.21/0.56/0.93, σ_e: 2.2/4.4/16.7 cm/s). In conclusion, this study characterizes repeatability of static and dynamic MRI-derived speech biomarkers using state-of-the-art imaging. The introduced framework can be used to guide future development of speech biomarkers. Test-retest MRI data are provided free for research use.

Age-Related Changes Between the Level of Velopharyngeal Closure and the Cervical Spine

The primary focus of this study was to assess age-related changes in the vertical distance of the estimated level of velopharyngeal closure in relation to a prominent landmark of the cervical spine: the anterior tubercle of cervical vertebra 1 (C1). Midsagittal anatomic magnetic resonance images were examined across 51 participants with normal head and neck anatomy between 4 and 17 years of age. Results indicate that age is a strong predictor (P = 0.002) of the vertical distance between the level of velopharyngeal closure relative to C1. Specifically, as age increases, the vertical distance between the palatal plane and C1 becomes greater resulting in the level of velopharyngeal closure being located higher above C1 (range 4.88-10.55 mm). Results of this study provide insights into the clinical usefulness of using C1 as a surgical landmark for placement of pharyngoplasties in children with repaired cleft palate and persistent hypernasal speech. Clinical implications and future directions are discussed.

Facial indices of north and South Indian adults: reliability in stature estimation and sexual dimorphism

INTRODUCTION

Anthropological studies have document differences in craniofacial features as well as in body characteristics among different populations. The variations in the facial morphology arise through a differential growth and they help us in distinguishing one person from another. These are controlled by a number of factors which include genetic heritage, climate and environment in which we live. Very few researchers from India have worked on these facial features with respect to population and environment. The present work was undertaken to determine whether facial variations were subjected to sexual dimorphism. In addition, comparison of facial indices was made, in order to determine possible variations between south and north Indian populations.

METHODS

The sample consisted of 200 individuals, 100 each from north and south Indian regions. Various facial parameters were determined on the basis of international anatomical description and facial indices were calculated.

RESULTS

North Indian males and females had highest facial height and upper facial height. Facial width of south Indians was more as compared to that of north Indians in both sexes. Regression equation was calculated to compare the probable height with actual height.

CONCLUSION

All the facial parameters and facial indices were found to be statistically highly significant and they showed inter-regional and gender variations. These indices will be beneficial in facial reconstruction surgeries, maxillofacial surgeries, and in forensic medicine, for estimating the stature and sex of an individual.

Developmental sexual dimorphism of the oral and pharyngeal portions of the vocal tract: an imaging study

PURPOSE

The anatomic origin for prepubertal vowel acoustic differences between male and female subjects remains unknown. The purpose of this study is to examine developmental sex differences in vocal tract (VT) length and its oral and pharyngeal portions.

METHOD

Nine VT variables were measured from 605 imaging studies (magnetic resonance imaging and computed tomography) of subjects between birth and age 19 years. Given sex differences in growth rate (Vorperian et al., 2009), assessment of sex differences was done through use of a localized comparison window of 60 months. Analysis entailed applying this comparison window first to 4 discrete age cohorts, followed by a progressive assessment in which this comparison window was moved in 1-month increments from birth across all ages.

RESULTS

Findings document significant postpubertal sex differences in both the oral and pharyngeal portions of the VT. They also document periods of significant prepubertal sex differences in the oral region first, followed by segments in the pharyngeal region.

CONCLUSIONS

Assessment of developmental sex differences using localized age ranges is effective in unveiling sex differences that growth rate differences may conceal. Findings on the presence of prepubertal sex differences in the oral region of the VT may clarify, in part, the anatomic basis of documented prepubertal acoustic differences.