Airway Growth in Preoperative Patients with Crouzon Syndrome.

Background: Obstructive sleep apnea is common in patients with Crouzon syndrome, yet it may be caused by multiple factors. This study aims to investigate the natural history of airway development in preoperative Crouzon patients, from infants to adults. Methods: Preoperative computed tomography (CT) scans (Crouzon syndrome, n = 73; control, n = 87) were divided into five age subgroups. CT scans were measured using Materialise software. Results: Before 6 months of age, nasal airway volume in patients with Crouzon syndrome was smaller than normal by 37% (p = 0.002), and the cross-sectional area at the choana reduced by 45% (p < 0.001). The reduction of nasal airway volume and cross-sectional area reached their nadir at 2 years of age, with shortening of 44% and 63% (both p < 0.001), respectively. They gradually caught up to normal dimensions after 6 years of age. Between 2 and 6 years, the pharyngeal airway in patients with Crouzon syndrome reduced 44% (p = 0.011) compared with controls. However, the airway cross-sectional area at condylion and gonion levels was less than normal, before 6 months (35%, p = 0.024) and (44%, p = 0.006) after 2 years of age, respectively. This reduction remains into adulthood. Conclusion: Nasal airway volume is more limited in children with Crouzon syndrome who are younger than 2 years of age. Whereas after 2 years of age, the pharyngeal airway develops significant volume restriction, leading to timing and specific treatment area foci based on the site of temporal maximal constriction.

Endochondral growth zone pattern and activity in the zebrafish pharyngeal skeleton.

BACKGROUND: Endochondral ossification is a major bone forming mechanism in vertebrates, defects in which can result in skeletal dysplasia or craniofacial anomalies in humans. The zebrafish holds great potential to advance our understanding of endochondral growth zone development and genetics, yet several important aspects of its biology remain unexplored. Here we provide a comprehensive description of endochondral growth zones in the pharyngeal skeleton, including their developmental progression, cellular activity, and adult fates. RESULTS: Postembryonic growth of the pharyngeal skeleton is supported by endochondral growth zones located either at skeletal epiphyses or synchondroses. Col2a1a and col10a1a in situ hybridization and anti-PCNA immunostaining identify resting-, hypertrophic- and proliferative zones, respectively, in pharyngeal synchondroses. Cellular hypertrophy and matrix deposition contribute little, if at all, to axial growth in most skeletal elements. Zebrafish endochondral growth zones develop during metamorphosis and arrest in adults. CONCLUSIONS: Two endochondral growth zone configurations in the zebrafish pharyngeal skeleton produce either unidirectional (epiphyses) or bidirectional (synchondroses) growth. Cell proliferation drives endochondral growth and its modulation, in contrast to mammalian long bones in which bone length depends more on cell enlargement during hypertrophy and intramembranous ossification is the default mechanism of bone growth in zebrafish adults.

The second pharyngeal pouch is generated by dynamic remodeling of endodermal epithelium in zebrafish.

Pharyngeal arches (PAs) are segmented by endodermal outpocketings called pharyngeal pouches (PPs). Anterior and posterior PAs appear to be generated by different mechanisms, but it is unclear how the anterior and posterior PAs combine. Here, we addressed this issue with precise live imaging of PP development and cell tracing of pharyngeal endoderm in zebrafish embryos. We found that two endodermal bulges are initially generated in the future second PP (PP2) region, which separates anterior and posterior PAs. Subsequently, epithelial remodeling causes contact between these two bulges, resulting in the formation of mature PP2 with a bilayered morphology. The rostral and caudal bulges develop into the operculum and gill, respectively. Development of the caudal PP2 and more posterior PPs is affected by impaired retinoic acid signaling or pax1a/b dysfunction, suggesting that the rostral front of posterior PA development corresponds to the caudal PP2. Our study clarifies an aspect of PA development that is essential for generation of a seamless array of PAs in zebrafish.

Activin A affects feeding by promoting the inner diameter and muscle development of the pharynx and oesophagus in zebrafish (Danio rerio) larvae.

Activin A belongs to the superfamily of transforming growth factor-ß and plays an important role in hormone regulation and tissue development. However, few research studies have been conducted on the effect of activin A on feeding organs in fish. In this study, the zebrafish (Danio rerio) larvae were treated with 1 ng ml-1 activin A for 8 days continuously. The haematoxylin and eosin (H&E) staining section results revealed that the transverse inner diameter of the pharynx and oesophagus significantly increased on the third and eighth days after treatment compared with the control group (P < 0.05). On the eighth day, the cross-sectional area of the pharyngeal muscle increased by 8638 µm2 compared to the control group (P < 0.05). The RNA in situ hybridization results also showed that the expression of skeletal muscle-specific genes (myog and myod) was significantly increased in pharyngeal muscle on the eighth day. Furthermore, the qRT-PCR results showed the expression of gh gene was significantly increased on the eighth day (P < 0.05). At the same time, more larvae in activin A group were able to feed larger brine shrimp (Artemia) than in the control group on the eighth day. In conclusion, activin A could affect feeding by promoting the inner diameter and muscle development of the pharynx and oesophagus in zebrafish larvae. This study is the first to report that the development of the pharynx and oesophagus can directly affect food intake in fish larvae, which provides a theoretical basis for the study of food intake of fish at an early stage.

Evaluating interactions of airway changes during growth with orthodontic treatment.

OBJECTIVE: The aim of this study was to longitudinally evaluate changes in the pharyngeal airway volume in adolescents treated with fixed orthodontic appliances compared to matched untreated adolescents and to assess its impact on airflow resistance. MATERIALS AND METHODS: The sample consisted of 16 adolescents (mean start age of 11 years 3 months) who had started and completed treatment at the orthodontic department of the University of Detroit Mercy School of Dental Medicine. This group was compared to a control that consisted of 16 adolescents (mean start age 12 years) who had two CBCTs with no treatment in between for the purpose of regular orthodontic evaluation. Differences in airway volume, length, minimum cross-sectional area, and the average cross-sectional area were calculated. RESULTS: The results indicated that the airway volume increased by 39% and was a statistically significant change (P<0.05). Regarding the influence on airflow resistance, the change in cross sectional area was significant in the group treated with fixed orthodontic appliances (P<0.03). CONCLUSION: Adolescents treated with fixed orthodontic appliances do experience an increase in airway volume, as well as a decrease in airway resistance to airflow compared to that in normal growth.

Nucleoporin 62-Like Protein is Required for the Development of Pharyngeal Arches through Regulation of Wnt/ß-Catenin Signaling and Apoptotic Homeostasis in Zebrafish.

We have previously observed the predominant expression of nucleoporin 62-like (Nup62l) mRNA in the pharyngeal region of zebrafish, which raises the question whether Nup62l has important implications in governing the morphogenesis of pharyngeal arches (PA) in zebrafish. Herein, we explored the functions of Nup62l in PA development. The disruption of Nup62l with a CRISPR/Cas9-dependent gene knockout approach led to defective PA, which was characterized by a thinned and shortened pharyngeal region and a significant loss of pharyngeal cartilages. During pharyngeal cartilage formation, prechondrogenic condensation and chondrogenic differentiation were disrupted in homozygous nup62l-mutants, while the specification and migration of cranial neural crest cells (CNCCs) were unaffected. Mechanistically, the impaired PA region of nup62l-mutants underwent extensive apoptosis, which was mainly dependent on activation of p53-dependent apoptotic pathway. Moreover, aberrant activation of a series of apoptotic pathways in nup62l-mutants is closely associated with the inactivation of Wnt/ß-catenin signaling. Thus, these findings suggest that the regulation of Wnt/ß-catenin activity by Nup62l is crucial for PA formation in zebrafish.

Growth Effects on Velopharyngeal Anatomy From Childhood to Adulthood.

Purpose The observed sexual dimorphism of velopharyngeal structures among adult populations has not been observed in the young child (4- to 9-year-old) population. The purpose of this study was to examine the age at which sexual dimorphism of velopharyngeal structures become apparent and to examine how growth trends vary between boys and girls. Method Static 3-dimensional magnetic resonance imaging velopharyngeal data were collected among 202 participants ranging from 4 to 21 years of age. Participants were divided into 3 groups based on age, including Group 1: 4-10 years of age, Group 2: 11-17 years of age, and Group 3: 18-21 years of age. Nine velopharyngeal measures were obtained and compared between groups. Results Significant sex effects were evident for levator length ( p = .011), origin to origin ( p = .018), and velopharyngeal ratio ( p = .036) for those in Group 2 (11-17 years of age). Sex effects became increasingly apparent with age, with 7 of 9 variables becoming significantly different between male and female participants in Group 3. Boys, in general, displayed a delayed growth peak in velopharyngeal growth compared to girls. Conclusion Results from this study demonstrate the growth of velopharyngeal anatomy with sexual dimorphism becoming apparent predominantly after 18 years of age. However, velopharyngeal variables displayed variable growth trends with some variables presenting sexual dimorphism at an earlier age compared to other velopharyngeal variables.

Growth and Development of Craniofacial Structures in Patients at Different Ages With Unrepaired Submucous Cleft Palate.

PURPOSE: Submucous cleft palate (SMCP) is a particular subtype of cleft palate deformity; research related to the craniofacial features of patients with SMCP is comparatively rare. The study objective was to perform a cephalometric comparison of the craniofacial features of patients with SMCP and non-cleft controls at different ages. MATERIALS AND METHODS: The sample in this cross-sectional study was composed of 2 groups: SMCP patients and non-cleft controls. The primary predictor variables were study group (cleft and non-cleft) and age. Age was divided into 3 groups. The outcome variables of interest were craniofacial measurements. The measurements used reflect cranial length, cranial angle, maxillary sagittal length and protrusion, maxillary vertical height, pharyngeal depth, facial height, mandibular length and protrusion, mandibular plane angle, and intermaxillary relation. Adjusted cephalometric craniofacial measurements between the groups were compared in 3 age groups using generalized linear models after being adjusted for age and gender. RESULTS: The study included 60 SMCP patients and 60 non-cleft controls. SMCP patients and non-cleft controls were divided into 3 subgroups: those aged 5 to 7 years, those aged 9 to 11 years, and those aged 18 to 30 years. Patients with SMCP at age 5 to 7 years showed a shortened cranial base length, maxillary sagittal length and height, and bony pharynx depth. Patients with SMCP at age 9 to 11 years showed a smaller maxillary sagittal length and bony pharynx depth and an inharmonious jaw relationship. Patients with SMCP at age 18 to 30 years showed a smaller maxillary sagittal length and height and an inharmonious jaw relationship. CONCLUSIONS: SMCP is associated with progressive maxillary retrognathism and reduced profile convexity from childhood to adulthood.

Development of Velopharyngeal Closure for Vocalization During the First 2 Years of Life.

Purpose: The vocalizations of young infants often sound nasalized, suggesting that the velopharynx is open during the 1st few months of life. Whereas acoustic and perceptual studies seemed to support the idea that the velopharynx closes for vocalization by about 4 months of age, an aeromechanical study contradicted this (Thom, Hoit, Hixon, & Smith, 2006). Thus, the current large-scale investigation was undertaken to determine when the velopharynx closes for speech production by following infants during their first 2 years of life. Method: This longitudinal study used nasal ram pressure to determine the status of the velopharynx (open or closed) during spontaneous speech production in 92 participants (46 male, 46 female) studied monthly from age 4 to 24 months. Results: The velopharynx was closed during at least 90% of the utterances by 19 months, though there was substantial variability across participants. When considered by sound category, the velopharynx was closed from most to least often during production of oral obstruents, approximants, vowels (only), and glottal obstruents. No sex effects were observed. Conclusion: Velopharyngeal closure for spontaneous speech production can be considered complete by 19 months, but closure occurs earlier for speech sounds with higher oral pressure demands.

Developmental changes in pharyngeal swallowing acoustics: a comparison of adults and children.

This study examined developmental differences in the acoustics of pharyngeal swallowing. Thirty-one young children (M = 4.5 years) and 29 adults (M = 22.5 years) were recorded swallowing thin liquid and puree boluses. In comparison with adults, children showed longer total swallow sound duration and duration to peak intensity, as well as greater variability in the duration to peak intensity and mean of the averaged spectrum in Hz. Thin and puree boluses differed in measures of duration, intensity and frequency of the averaged sound spectrum, although these effects did not interact with age. The increased variability in swallowing observed in children paralleled that found in acoustic measures of vowel formants, although speech and swallowing acoustic measures were uncorrelated. Using Formant 2 frequency as a proxy measure of vocal tract length, the age differences in swallowing acoustics appear to be independent of physical size, although associations between duration to peak intensity and pharyngeal size warrant further investigation. These findings suggest acoustic measures of swallowing are sensitive to developmental status, possibly reflecting ongoing refinement of the pharyngeal swallow across childhood, and support continued research into the use of digital cervical auscultation as a tool to assess the efficiency and stability of the swallowing neuromuscular control system in children and adults.

Linear dimensions of normal upper airway structure by magnetic resonance imaging in Chinese Han infants and preschool children.

OBJECTIVES: To establish normative data of upper airway structure in Chinese Han infants and preschool children. METHODS: Magnetic resonance imaging (MRI) scans of 521 Chinese Han infants and preschool children (225 girls, 296 boys) aged from 1 day to 72 months were selected from the children who underwent head MRI at the Capital Institute of Pediatrics Affiliated Children Hospital, Beijing, China. No subjects had sleep-disordered breathing or associated conditions that may have affected the upper airway anatomy. The upper airway dimensions and surrounding soft tissue sizes were measured along the mid-sagittal and axial images. RESULTS: On images from the mid-sagittal image, the normative values of the following were obtained for all age group: thickness of the adenoid and nasopharyngeal area, length and thickness of the soft palate, length and height of the tongue, length of upper airway, distance between the mental spine and clivus, and the adenoid oblique width, soft palate oblique width, and tongue oblique width along the mental spine-clivus line. Normative values of the mean tonsillar width and intertonsillar space on the axial images were also obtained. There were no differences in any measurements between boys and girls in either infants or preschool children. Older children had larger airway dimensions, as expected. CONCLUSION: Normative values for upper airway structure in Chinese Han infants and preschool children assessed by MRI were established. The upper airway dimension and surrounding soft tissues size, including soft palate, adenoid, tongue, and tonsils, were increased with age. There were no gender differences during the first six years of life. These data may prove useful when studying airway disease in Chinese Han children.

"High-Throughput Characterization of Region-Specific Mitochondrial Function and Morphology".

The tissue-specific etiology of aging and stress has been elusive due to limitations in data processing of current techniques. Despite that many techniques are high-throughput, they usually use singular features of the data (e.g. whole fluorescence). One technology at the nexus of fluorescence-based screens is large particle flow cytometry ("biosorter"), capable of recording positional fluorescence and object granularity information from many individual live animals. Current processing of biosorter data, however, do not integrate positional information into their analysis and data visualization. Here, we present a bioanalytical platform for the quantification of positional information ("longitudinal profiling") of C. elegans, which we posit embodies the benefits of both high-throughput screening and high-resolution microscopy. We show the use of these techniques in (1) characterizing distinct responses of a transcriptional reporter to various stresses in defined anatomical regions, (2) identifying regions of high mitochondrial membrane potential in live animals, (3) monitoring regional mitochondrial activity in aging models and during development, and (4) screening for regulators of muscle mitochondrial dynamics in a high-throughput format. This platform offers a significant improvement in the quality of high-throughput biosorter data analysis and visualization, opening new options for region-specific phenotypic screening of complex physiological phenomena and mitochondrial biology.

Yorkie is required to restrict the injury responses in planarians.

Regeneration requires the precise integration of cues that initiate proliferation, direct differentiation, and ultimately re-pattern tissues to the proper size and scale. Yet how these processes are integrated with wounding responses remains relatively unknown. The freshwater planarian, Schmidtea mediterranea, is an ideal model to study the stereotyped proliferative and transcriptional responses to injury due to its high capacity for regeneration. Here, we characterize the effector of the Hippo signalling cascade, yorkie, during planarian regeneration and its role in restricting early injury responses. In yki(RNAi) regenerating animals, wound responses are hyper-activated such that both stem cell proliferation and the transcriptional wound response program are heighted and prolonged. Using this observation, we also uncovered novel wound-induced genes by RNAseq that were de-repressed in yki(RNAi) animals compared with controls. Additionally, we show that yki(RNAi) animals have expanded epidermal and muscle cell populations, which we hypothesize are the increased sources of wound-induced genes. Finally, we show that in yki(RNAi) animals, the sensing of the size of an injury by eyes or the pharynx is not appropriate, and the brain, gut, and midline cannot remodel or scale correctly to the size of the regenerating fragment. Taken together, our results suggest that yki functions as a key molecule that can integrate multiple aspects of the injury response including proliferation, apoptosis, injury-induced transcription, and patterning.

Chin-throat anatomy: Normal relations and changes following orthognathic surgery and growth modification.

OBJECTIVES: To determine if a new facial line (T), tangent to the throat, intersects the mandibular border in anterior (ANT) and posterior (POST) parts in proportions varying with facial configuration, and to evaluate the association between chin projection and throat inclination and the potential for the T-line to reflect this association. MATERIALS AND METHODS: Measurements on profile photographs and cephalograms of 135 adults (aged 18-50 years)-45 each of Class I, II, and III (CI, CII, CIII) malocclusions-included ANT and POST, chin-throat (CTA), and mento-cervical (MCA) angles. Pre- and posttreatment measurements were compared in two subgroups (n = 25 each) of CII and CIII orthognathic surgery patients and in CII, division 1 early-treatment patients (n = 63). Statistics included analysis of variance and t-test for group differences, and Pearson correlation for associations among variables. RESULTS: ANT was nearly equal to POST in CI (50.99%) and CIII (51.86%) subjects and shorter in CII (36.01%) subjects. CTA and MCA were greater in CII profiles and smaller in CIII profiles. Significant differences (P < .0001) were observed for ANT, POST, CTA, and MCA between Classes I/II and II/III and for MCA between Classes II/III (P = .016). High correlations were noted between ANT and CTA in Classes I (r = -0.83), II (r = -0.73), and III (r = -0.68). In surgically treated patients, posttreatment measurements approached CI values. In the early-treatment group, ANT increased but remained smaller than POST; CTA decreased by nearly 13%. CONCLUSIONS: Chin-throat relations and chin extension are associated and require routine assessment in terms of diagnosis and treatment outcome. A practical tool to assess chin-throat relationship, the T-line bisects the mandibular body nearly equally in Class I faces.

Identification and characterization of a novel multifunctional placenta specific protein 8 in Dugesia japonica.

Placenta specific protein 8 (Plac8) has been well studied in vertebrates, yet little is known in invertebrates. In this study, a novel Plac8 from the planarian Dugesia japonica was identified and its functions in immune responses and development were characterized. Our results show that Djplac8 was expressed in the pharynx, epidermis and intestine of intact adult planarian. The expression of DjPlac8 increased significantly upon lipopolysaccharide (LPS) challenge, and inhibited the growth of the Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), suggesting the role of Plac8 in immune response. Spatial and temporal expression and distribution of DjPlac8 mRNA in regenerated planarians indicates that DjPlac8 was mainly expressed in the pharynx. In situ hybridization also revealed the elevated expression of the DjPlac8 gene in the embryonic pharynx, germ band and parenchyma cells, indicating an important role in embryonic development of D. japonica. When DjPlac8 was deactivated by RNA interference-mediated knockdown, the head of planarians underwent abnormal development. In summary, we identified DjPlac8 as a novel multifunctional protein that plays essential roles in immune response and development of planarians.

[Nasopharyngeal changes in 8-13 years old healthy children in China: a longitudinal study].

Objective: Nasopharynx is an important compartment of the upper airway. It is closely associated with the characteristic craniofacial skeletal pattern related to sleep breathing. The present study aimed to investigate the growth pattern of the nasopharynx during rapid puberty growth period. Methods: Thirty non-snoring children (aged 8 to 11 years old) were selected by means of questionnaires and clinical examination. Periodic yearly follow up using MRI, lateral cephalogram, and polysomnograph (PSG) was done in these children. Fifty-one final mixed longitudinal samples were consisted of 23 children completed three consecutive follow-up, and 5 children completed two consecutive follow-up. The yearly changes of the nasopharynx and craniofacial structures were measured. ANOVA was used to evaluate the yearly growth of the nasopharynx. Correlated analysis was used to explore the potential influencing factors of craniofacial structures. Results: The rapid growth period of the nasopharynx located in the age range of 8-10 years old, during which the transverse dimension of the nasopharynx developed rapidly, while the rapid development of the sagittal dimension of the nasopharynx was around 12-13 years old. The growth of the nasopharynx was continuous. The changes in the cross-sectional area of the nasopharynx (⊿CSA) was positively correlated with the changes in distance between mandible of glossopharyngeus (⊿M), distance of hyoid to cervical anterior surface (⊿H-CVP), and anterior pharyngeal distance of glossopharyngeus (⊿AD) (r=0.363, 0.363, 0.323, respectively, all P<0.05). The changes in the volume of the nasopharynx (⊿V) was positively correlated with the changes in upper facial height (⊿N-ANS), ⊿M, and ⊿AD (r=0.336, 0.413, 0.478, respectively, all P<0.05). The changes in the sagittal dimension of the nasopharynx (⊿S) was negatively correlated with angulation in supramental and anatomical horizontal line (⊿SNB) (r=-0.322, P=0.045). The changes in the transverse dimension of the nasopharynx (⊿T) was negatively correlated with the changes in adenoid (⊿A) (r=-0.411, P=0.009). Conclusions: The growth and development of the nasopharynx was early and continuous, which could be affected by the development of either maxilla or mandible.

Vertical and sagittal morphology of the facial skeleton and the pharyngeal airway.

AIM: The aim of this study was to evaluate the relationship between sagittal and vertical facial skeletal morphology, and the morphology of the upper and lower pharyngeal airway. MATERIAL AND METHODS: Pharyngeal airway structures were studied in 101 healthy children (36 boys and 65 girls) aged 7-17 years who were referred for orthodontic treatment. The sample was divided into two groups: according size of the ANB angle group Class I: angle till 4º was considered as skeletal Angle Class I; group Class II: ANB angle more than 4º, considered as skeletal Angle Class II. The vertical pattern was classified using the SN-MP angle, with angle less than 34 taken as normal, and more than 34 - as high vertical growth patterns. The linear measurements and angles were calculated using special purpose software (Dolphin v. 11.0). Pharyngeal width was measured at different point levels using Arnett/Gunson airway analysis. RESULTS: A statistically significant difference between the two groups, and airway width on all levels was statistically significantly narrower in Angle Class II. Pearson's correlation coefficient showed a negative statistically significant dependence between nasopharyngeal airway, oropharyngeal airway space, and SN-MP angle. CONCLUSION: Statistically significantly narrower airways were found in patients with ANB more than 4°. In groups divided by SN-MP angle statistically significant difference have not found. Nasopharyngeal airway and oropharyngeal airway spaces statistically significantly negatively correlated with the SN-MP angle: the bigger the SN-MP angle, the smaller were nasopharyngeal and oropharyngeal airway spaces.

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.

Racial Variations in Velopharyngeal and Craniometric Morphology in Children: An Imaging Study.

PURPOSE: The purpose of this study is to examine craniometric and velopharyngeal anatomy among young children (4-8 years of age) with normal anatomy across Black and White racial groups. METHOD: Thirty-two healthy children (16 White and 16 Black) with normal velopharyngeal anatomy participated and successfully completed the magnetic resonance imaging scans. Measurements included 11 craniofacial and 9 velopharyngeal measures. RESULTS: Two-way analysis of covariance was used to determine the effects of race and sex on velopharyngeal measures and all craniometric measures except head circumference. Head circumference was included as a covariate to control for overall cranial size. Sex did not have a significant effect on any of the craniometric measures. Significant racial differences were demonstrated for face height. A significant race effect was also observed for mean velar length, velar thickness, and velopharyngeal ratio. CONCLUSION: The present study provides separate craniofacial and velopharyngeal values for young Black and White children. Data from this study can be used to examine morphological variations with respect to race and sex.

Composite growth model applied to human oral and pharyngeal structures and identifying the contribution of growth types.

The growth patterns of different anatomic structures in the human body vary in terms of growth amount over time, growth rate and growth periods. The oral and pharyngeal structures, also known as vocal tract structures, are housed in the craniofacial complex where the cranium/brain follows a distinct neural growth pattern, and the face follows a distinct somatic or skeletal growth pattern. Thus, it is reasonable to expect the oral and pharyngeal structures to follow a combined or mixed growth pattern. Existing parametric growth models are limited in that they are mainly focused on modeling one particular type of growth pattern. In this paper, we propose a novel composite growth model using neural and somatic baseline curves to fit the combined growth pattern of select vocal tract structures. The method can also determine the overall percent contribution of each of the growth types.