Magnetic resonance imaging of the levator veli palatini muscle during speech

Sex Differences in Velopharyngeal Anatomy of 9- and 10-Year-Old Children

OBJECTIVE

Understanding the normal anatomy of velopharyngeal (VP) mechanism and the emergence of sexual dimorphism provides valuable insights into differences of VP anatomy among males and females. The purpose of this study is to examine sex differences in VP anatomy in a large data set of 3,248 9- and 10-year-old children.

METHOD

Static three-dimensional magnetic resonance imaging was used to compare five VP characteristics including velar length, velar thickness, effective velar length, levator veli palatini muscle length, and pharyngeal depth between age-matched males (n = 1,670) and females (n = 1,578). Additionally, these dimensions were used to determine the VP ratio and effective VP ratio.

RESULTS

Males showed significantly larger dimensions for all VP distances and significantly lower ratios of velar length and effective velar length to pharyngeal depth (p < .05). The magnitude of these effect sizes was small to medium, with Cohen's d values ranging from 0.12 to 0.63. Additionally, the VP ratio and effective VP ratio are lower among males compared to females (p < .05).

CONCLUSIONS

Results suggest the presence of sexual dimorphism in the VP mechanism among 9- and 10-year-old children. These findings emphasize the necessity of using different normative data for males and females when making comparisons to patients with cleft palate.

Anatomical and Physiological Changes Following Primary Palatoplasty Using "The Buccal Flap Approach"

OBJECTIVE

The purpose of this study was to determine the anatomical differences among selected individuals with a cleft palate repaired using "The Buccal Flap Approach" during primary palatoplasty compared to aged-matched participants without cleft palate.

DESIGN

Observational, prospective.

SETTING

Two regional hospitals.

PARTICIPANTS

A total of 30 adult males consisting of 15 adults born with cleft palate who received the Double Opposing Z-Plasty plus Buccal Flaps (DOZP  +  BF) repair at the time of primary palatoplasty and no history of secondary speech surgery or orthognathic surgery and 15 adults without a history of cleft palate.

INTERVENTIONS

All participants underwent MRI to visualize anatomy.

MAIN OUTCOME MEASURES

Ten velopharyngeal and craniofacial anatomical measures.

RESULTS

No statistically significant differences between groups were observed for velar thickness, velar length, pharyngeal depth, NSBa angle, SNB angle, or levator veli palatini length. Individuals with the DOZP  +  BF presented with a greater effective velar length (p < .001), greater effective VP ratio (p < .001), smaller SNA angle (p < .001), and smaller maximal velar stretch (p < .001) compared to the control participants.

CONCLUSIONS

This study suggests that adult males who received the DOZP  +  BF repair at the time of primary palatoplasty and no history of secondary speech surgery or orthognathic surgery present with a longer effective velar length and larger effective VP ratio in comparison to the non-cleft group. Future research is needed to compare patients with and without favorable outcomes from multiple surgical types to fully understand how surgical techniques alter the anatomy.

Assessment of the Velopharyngeal Mechanism at Rest and During Speech in Children With 22q11.2DS: A Cross-Sectional Study

OBJECTIVE

Velopharyngeal dysfunction (VPD) associated with 22q11.2 deletion syndrome (22q11.2DS) has a complex etiology. This study had 3 aims: (1) assess differences in velopharyngeal and levator muscle configuration during rest versus sustained speech production (2) compare differences in velopharyngeal changes between children with and without 22q11.2DS (3) examine the relationship between adenoid thickness, pharyngeal depth, and velopharyngeal changes.

DESIGN

Cross-sectional.

METHODS

A total of 22 participants, 11 with 22q11.2DS and 11 controls with normal speech and velopharyngeal anatomy (ages 4-12 years), underwent nonsedated MRI at rest and during sustained /i/. Differences in velar and levator muscle contraction across the 2 different conditions were analyzed, using matched paired t-tests. Mean differences across participant groups were examined. Correlation analyses were also conducted.

RESULTS

When comparing differences between rest and sustained phoneme production (aim 1), significant (P < .05) differences were noted for all velar and levator muscle variables. For differences in velopharyngeal changes between children with and without 22q11.2DS (aim 2), VP ratio and effective VP ratio were noted to be significantly different. Pharyngeal depth and adenoid thickness were correlated with velar and levator muscle change measures and ratios (aim 3).

CONCLUSION

Results from this study provide quantitative in vivo measurements of the contracted levator muscle and velum in young children with 22q11.2DS. Results demonstrated that VP ratio and EVP ratio are significantly different between children with and without 22q11.2DS and that pharyngeal depth is a strong clinical determinant of VPD in children with 22q11.2DS.

Three-dimensional Anatomy of the Velopharyngeal Muscles in the Cleft Palate

OBJECTIVE

We have used micro-computed tomography (CT) to elucidate the relationship between the muscle fibers in specimens with cleft palate. These findings could be useful for muscle reconstruction in cleft palate repair and to better understand cleft palate speech.

DESIGN

Cadaveric anatomical study.

PARTICIPANTS

This study included three specimens with cleft palate.

INTERVENTION

The specimens were stained with phosphomolybdic acid and scanned by Micro-CT.

MAIN OUTCOME MEASURE(S)

The anatomy of the muscles.

RESULTS

Using 2D projection images and 3D reconstruction models, subtle anatomical structures could be observed in the muscles. The attachment of the levator veli palatini (LVP) was not at the posterior edge of the hard palate or palatine aponeurosis (PA), but at the anterior 21.71-44.2% of the cleft edge. The palatopharyngeal (PP) was composed of two bundles: inferior and superior heads, which clasped the LVP. The uvularis was unevenly distributed, and located on both sides of the cleft edge, originating at the edge. The palatoglossus, superior constrictor of pharynx and anatomical structure around the pterygoid hamulus, were normal. The PA, PP and LVP were attached to the cleft edge from front to back, in that order. The position of the uvularis was not fixed.

CONCLUSIONS

With the help of Micro-CT technology, detailed anatomical features and the relationship between muscles could be visualized. In the specimen with cleft palate, muscles in the soft palate were associated with the pharyngeal muscles, which formed the 3D "velopharyngeal muscles complex." These findings provide anatomical evidence for muscle reconstruction in cleft palate repair.

Preliminary Development of an MRI Atlas for Application to Cleft Care: Findings and Future Recommendations

OBJECTIVE

To introduce a highly innovative imaging method to study the complex velopharyngeal (VP) system and introduce the potential future clinical applications of a VP atlas in cleft care.

DESIGN

Four healthy adults participated in a 20-min dynamic magnetic resonance imaging scan that included a high-resolution T2-weighted turbo-spin-echo 3D structural scan and five custom dynamic speech imaging scans. Subjects repeated a variety of phrases when in the scanner as real-time audio was captured.

SETTING

Multisite institution and clinical setting.

PARTICIPANTS

Four adult subjects with normal anatomy were recruited for this study.

MAIN OUTCOME

Establishment of 4-D atlas constructed from dynamic VP MRI data.

RESULTS

Three-dimensional dynamic magnetic resonance imaging was successfully used to obtain high quality dynamic speech scans in an adult population. Scans were able to be re-sliced in various imaging planes. Subject-specific MR data were then reconstructed and time-aligned to create a velopharyngeal atlas representing the averaged physiological movements across the four subjects.

CONCLUSIONS

The current preliminary study examined the feasibility of developing a VP atlas for potential clinical applications in cleft care. Our results indicate excellent potential for the development and use of a VP atlas for assessing VP physiology during speech.

Incorporating Velopharyngeal MRI into the Clinical Decision-Making Process for a Patient Presenting with Velopharyngeal Dysfunction Following a Failed Palatoplasty

This clinical report describes the implementation of magnetic resonance imaging (MRI) to evaluate a patient with long-standing velopharyngeal dysfunction. She was referred to the craniofacial clinic at age 10 with no prior surgical history and subsequently completed a Furlow palatoplasty due to a suspected submucous cleft palate. However, results were unfavorable with minimal improvement in speech or resonance. The clinical presentation, treatment, outcomes, and contributions from MRI for secondary surgical planning are described. Addition of MRI into the clinical workflow provided insights into the anatomy and physiology of the velopharyngeal mechanism that were unable to be obtained from nasendoscopy and speech evaluation alone.

An Exploratory Investigation of the Palatoglossus Muscle in Children Using Magnetic Resonance Imaging

PURPOSE

There is currently little evidence reporting the typical morphology of the palatoglossus (PG) muscle. The primary purpose of this exploratory study is to determine whether magnetic resonance imaging (MRI) methods used to quantify the morphology of the levator veli palatini (LVP) muscle can be applied to the PG. The secondary purpose is to provide preliminary data regarding the relationship between the LVP and PG muscles in children.

METHOD

Ten children between ages of 4 and 7 years participated in this study. Each participant was scanned using a nonsedated, child-friendly protocol with a T2-weighted, three-dimensional anatomical scan to obtain images of the oropharyngeal anatomy. Custom, oblique-coronal image planes were created to visualize and measure the LVP and PG muscles in their entirety from origin to insertion. Thermo Scientific Amira Software was used to obtain 2D measurements of PG muscle length, width, velar insertion distance, lingual insertion distance, and several angle measurements.

RESULTS

The PG ranged from 17.95 to 26.96 mm in length across participants. Velar insertion distance ranged from 17.22 to 30.95 mm. Lingual insertion distance ranged from 26.91 to 36.02 mm. Width ranged from 2.32 to 3.08 mm. The angle formed by the PG and LVP muscle planes ranged from 7.3° to 52.7°. The LVP insertion angle ranged from 42.5° to 75.9°. The PG insertion angle ranged from 16.9° to 52.3°.

CONCLUSIONS

MRI was successful in visualizing the PG muscle. The PG was consistent in size and shape within an individual participant but varied across the participant cohort.

Growth Effects on Velopharyngeal Anatomy Within the First 2 Years of Life

PURPOSE

Limited quantitative data exist regarding growth of the velopharynx within the first 2 years of life. The purpose of this study was to (a) quantify changes in velopharyngeal structures due to growth during the first 2 years of life, (b) examine the impact of sex and race within this age range, and (c) provide normative measures for comparison to individuals with cleft palate.

METHOD/DESCRIPTION

A retrospective chart review was completed of all patients up to 24 months of age that underwent magnetic resonance imaging of the head for medical necessity within the past 18 months using a three-dimensional fluid-attenuated inversion recovery sequence. Measurements of the velopharynx were obtained from 200 scans consistent with previous literature. Participants were divided into five groups based on corrected age for comparison. Variables of interest included adenoid depth, angle of origin, effective velopharyngeal ratio, effective velar length, levator veli palatini length, origin-origin distance, pharyngeal depth, sagittal angle, velopharyngeal ratio, velar insertion distance, velar length, and velar thickness.

RESULTS

Velopharyngeal dimensions were significantly different among corrected age groups after controlling for sex and race. Regarding age, analyses revealed significant differences in all variables of interest except effective velopharyngeal ratio. Regarding sex, significant differences were observed for angle of origin, effective velopharyngeal ratio, effective velar length, levator veli palatini muscle length, and velar insertion distance. Regarding race, a significant difference was only observed for angle of origin.

CONCLUSIONS

Results of this study demonstrate growth of velopharyngeal anatomy in normative infants with race and sex effects apparent in children up to 24 months of age. Variable growth trends were observed among different velopharyngeal measures.

The nasopharynx as a window to half a billion years of evolutionary change to the upper respiratory tract

The nasopharynx is a region at the nexus of several vital physiological systems, including the nasal cavity, oral cavity, braincase, middle ear, and cervical vertebrae. It has undergone pronounced morphological change over the course of tetrapod, mammalian, and human evolution. However, despite its place in evolutionary history, the nasopharynx has received relatively little attention. This special issue focuses on "the evolution, development, and functional morphology of the nasopharynx and its boundaries." Topics covered here include evolutionary developmental biology (or evo-devo), nasopharyngeal adaptions in bats, the importance of the nasopharynx and adjacent structures over the course of human evolution, normal development, middle ear morphology, clinical importance, and the study of the nasopharynx throughout history. Contributions to this special issue range among reviews and syntheses, descriptive analyses, phylogenetic analysis, traditional morphometrics, three-dimensional geometric morphometrics, and computational fluid dynamics. Here, we discuss the central importance of the nasopharynx as can be seen through vertebrate paleontology and comparative morphology. It is via the composite evolutionary history of the nasopharyngeal boundaries that our origins may be better understood, starting with the derivation of the choanae from the median olfactory pit of jawless fish nearly half a billion years ago to the basicranial flexion and facial reduction that distinguish Homo sapiens from all other living mammals. Indeed, the nasopharynx must be acknowledged for its importance in the processes of encephalization and acquisition of speech that have become the hallmark of our species.

Comparison of Real-Time Speech Magnetic Resonance Imagings With Perceptual Speech Analysis in Evaluation Velopharyngeal Sphincter Function

ABSTRACT

Identifying substantial data and their normative values related to velopharyngeal structures in cleft palate patients may have clinical significance, in order to selection of surgical intervention and prediction of postsurgical outcomes. Previous studies are lack of referring certain anatomic locations or distances that may have affect on speech intelligibility, especially in dynamic state. The aim of this study is to investigate effectiveness of magnetic resonance imagings on the velopharyngeal sphincter function and the correlation with speech intelligibility after functional cleft palate repair. Seventeen patients with repaired cleft palate by single surgeon were enrolled in this study.Quantitative velopharyngeal measures from the oblique coronal plane and midsagittal plane in static and dynamic positions were collected. Patients' speech intelligibility was evaluated by using Pittsburgh Weighted Speech Scale and nasalance score was also measured. Correlation analysis methods were used for evaluating relation between MRI gathered measurements and speech intelligibility scores for determiningconsequential data.Our study shows that the velar knee-posterior pharyngeal wall distance measurement while explosive sound production is the most related data with speech intelligibility. Although future works with more sample number is needed, according to current study the authors think magnetic resonance imagings is a very helpful method in providing reliable information.

Does the Type of MRI Sequence Influence Perceived Quality and Measurement Consistency in Investigations of the Anatomy of the Velopharynx?

PURPOSE

The purpose of this study was to evaluate perceived image quality, confidence in identifying key velopharyngeal landmarks, and reliability of making velopharyngeal measures between 3-dimensional (3-D) and 2-D magnetic resonance imaging (MRI) methods and between T1-, T2-, and proton density (PD)-weighted sequences.

METHODS

Twelve healthy participants completed an MRI study. Three raters assessed overall image quality and their ability to identify key anatomic features within the images. A single rater evaluated the reliability of making measures between imaging methods and sequence types to determine if image type (2-D and 3-D) or image sequence (T1, T2, PD weighted) resulted in different values for key velopharyngeal landmarks.

RESULTS

An analysis of variance test revealed image quality was rated significantly different based on the scan type (P < .001) and the sequence used (P = .015). Image quality was rated higher among 2-D MR images compared to 3-D, and higher among T2 sequences compared to T1- and PD-weighted imaging methods. In contrast, raters favored 3-D sequences over 2-D sequences for identifying velopharyngeal landmarks. Measures of reliability revealed scan type significantly impacted 2 of the 6 variables but to a minimal degree; however, sequence type had no impact on measures of reliability across all variables.

CONCLUSION

Results of the study suggest the scan type and sequence used are factors that likely do not impact the reliability of measures. Based on image quality, the recommended technique for velopharyngeal imaging would be using a 2-D T2-weighted technique. However, based on the ability to identify key landmarks, a 3-D T1- or PD-weighted technique was favored.

A Cadaveric and Magnetic Resonance Imaging Investigation of the Salpingopharyngeus

Purpose The aim of the study was to update our information regarding the salpingopharyngeus (SP) muscle using cadaveric and in vivo magnetic resonance imaging (MRI) data. Primary objectives were to (a) observe the presence/absence of the muscle and (b) quantify and describe its dimensions and course. Method SP specimens from 19 cadavers (10 women, nine men) were analyzed. Following head bisection, measurements of SP, including width of the cartilaginous attachment (CW) and width of the superior muscle base (SMW), were taken before and after removal of the overlying mucosa. In addition, SP was analyzed in 15 healthy subjects (eight men, seven women) using high-resolution three-dimensional MRI data. CW and SMW measures were replicated in the paraxial MRI view. Results The presence of the salpingopharyngeal fold and muscle was confirmed bilaterally in all cadaveric and living subjects. Following mucosa removal, mean cadaveric CW and SMW measurements were 5.6 and 3.8 mm, respectively. Mean in vivo CW and SMW were 6.1 and 3.7 mm, respectively. Results from the hierarchical regression analyses revealed that, in both cadaveric and living groups, SMW is dependent on the relationship between age and body weight, after controlling for sex. Conclusions The salpingopharyngeal fold and SP muscle are always present bilaterally and can be quantified at the superior origin using both cadaveric and in vivo three-dimensional MRI data. Though both the superior origin and inferior course of SP are highly variable, the size of the SP muscle is dependent on characteristics known to affect muscle fibers, such as the relationship between age and body weight. Given the consistent and quantifiable presence of the SP muscle, its potential role in velopharyngeal function for speech and swallowing is reconsidered. Supplemental Material https://doi.org/10.23641/asha.14347859.

Effective Velopharyngeal Ratio: A More Clinically Relevant Measure of Velopharyngeal Function

Purpose Velopharyngeal (VP) ratios are commonly used to study normal VP anatomy and normal VP function. An effective VP (EVP) ratio may be a more appropriate indicator of normal parameters for speech. The aims of this study are to examine if the VP ratio is preserved across the age span or if it varies with changes in the VP portal and to analyze if the EVP ratio is more stable across the age span. Method Magnetic resonance imaging was used to analyze VP variables of 270 participants. For statistical analysis, the participants were divided into the following groups based on age: infants, children, adolescents, and adults. Analyses of variance and a Games-Howell post hoc test were used to compare variables between groups. Results There was a statistically significant difference (p < .05) in all measurements between the age groups. Pairwise comparisons reported statistically significant adjacent group differences (p < .05) for velar length, VP ratio, effective velar length, adenoid depth, and pharyngeal depth. No statistically significant differences between adjacent age groups were reported for the EVP ratio. Conclusions Results from this study report the EVP ratio was not statistically significant between adjacent age groups, whereas the VP ratio was statistically significant between adjacent age groups. This study suggests that the EVP ratio is more correlated to VP function than the VP ratio and provides a more stable and consistent ratio of VP function across the age span.

Evaluation of the Symmetry of the Levator Veli Palatini Muscle and Velopharyngeal Closure Among a Noncleft Adult Population

PURPOSE

The goal of this study is to determine the typical range of asymmetry between the length and thickness of the levator veli palatini muscle and to explore the impact of the observed asymmetry on velopharyngeal closure. A second objective is to report normative length and thickness of the levator veli palatini muscle among adults with typical velopharyngeal anatomy.

METHOD

Magnetic resonance imaging (MRI) data and Amira 5.5 Visualization software were used to evaluate the levator veli palatini muscle among 89 participants with typical velopharyngeal anatomy. Flexible nasopharyngoscopy was used to determine the function of velopharyngeal closure among 39 of the 89 participants with typical velopharyngeal anatomy to examine the functional impact of observed asymmetry.

RESULTS

Matched paired t tests demonstrated a nonsignificant difference between the length and thickness of the right and left levator muscle. The mean difference between the right and left length of the levator muscle was 2.28 mm but ranged from 0.09 mm to 10.37 mm. In all cases where individuals displayed asymmetry in the levator muscle through MRI, there was no observed impact on the symmetry of velopharyngeal closure.

DISCUSSION

This study suggest that differences in the right and left levator veli palatini muscle are not significant among individuals without cleft palate. However, among individual cases where asymmetry was sizeable, there was no direct impact on the closure pattern. This may suggest there are multiple factors that contribute to asymmetrical velopharyngeal closure that are beyond the level of the levator veli palatini muscle.

Velopharyngeal Muscle Morphology in Children With Unrepaired Submucous Cleft Palate: An Imaging Study

OBJECTIVE

To identify quantitative and qualitative differences in the velopharyngeal musculature and surrounding structures between children with submucous cleft palate (SMCP) and velopharyngeal insufficiency (VPI) and noncleft controls with normal anatomy and normal speech.

METHODS

Magnetic resonance imaging was used to evaluate the velopharyngeal mechanism in 20 children between 4 and 9 years of age; 5 with unrepaired SMCP and VPI. Quantitative and qualitative measures of the velum and levator veli palatini in participants with symptomatic SMCP were compared to noncleft controls with normal velopharyngeal anatomy and normal speech.

RESULTS

Analysis of covariance revealed that children with symptomatic SMCP demonstrated increased velar genu angle (15.6°, P = .004), decreased α angle (13.2°, P = .37), and longer (5.1 mm, P = .32) and thinner (4 mm, P = .005) levator veli palatini muscles compared to noncleft controls. Qualitative comparisons revealed discontinuity of the levator muscle through the velar midline and absence of a musculus uvulae in children with symptomatic SMCP compared to noncleft controls.

CONCLUSIONS

The levator veli palatini muscle is longer, thinner, and discontinuous through the velar midline, and the musculus uvulae is absent in children with SMCP and VPI compared to noncleft controls. The overall velar configuration in children with SMCP and VPI is disadvantageous for achieving adequate velopharyngeal closure necessary for nonnasal speech compared to noncleft controls. These findings add to the body of literature documenting levator muscle, musculus uvulae, and velar and craniometric parameters in children with SMCP.

Identifying Predictors of Levator Veli Palatini Muscle Contraction During Speech Using Dynamic Magnetic Resonance Imaging

Purpose The purpose of this study was to identify predictors of levator veli palatini (LVP) muscle shortening and maximum contraction velocity in adults with normal anatomy. Method Twenty-two Caucasian English-speaking adults with normal speech and resonance were recruited. Participants included 11 men and 11 women (M = 22.8 years, SD = 4.1) with normal anatomy. Static magnetic resonance images were obtained using a three-dimensional static imaging protocol. Midsagittal and oblique coronal planes were established for visualization of the velum and LVP muscle at rest. Dynamic magnetic resonance images were obtained in the oblique coronal plane during production of "ansa." Amira 6.0.1 Visualization and Volume Modeling Software and MATLAB were used to analyze images and calculate LVP shortening and maximum contraction velocity. Results Significant predictors (p < .05) of maximum LVP shortening during velopharyngeal closure included mean extravelar length, LVP origin-to-origin distance, velar thickness, pharyngeal depth, and velopharyngeal ratio. Significant predictors (p < .05) of maximum contraction velocity during velopharyngeal closure included mean extravelar length, intravelar length, LVP origin-to-origin distance, and velar thickness. Conclusions This study identified six velopharyngeal variables that predict LVP muscle function during real-time speech. These predictors should be considered among children and individuals with repaired cleft palate in future studies.

Contracted Extravelar Segments of the Levator Veli Palatini Muscle: A Magnetic Resonance Imaging Morphometric Study

OBJECTIVES

To provide detailed descriptions of contraction-induced morphometric changes in the extravelar segments of the levator veli palatini (LVP) muscle using 3-dimensional (3-D) magnetic resonance imaging (MRI).

DESIGN

Three-dimensional MRI data were acquired at rest and during "silent /i/" from 4 singers. During silent /i/, participants voluntarily sustained velar elevation while breathing orally for the entire scan time. Focusing on the extravelar segments, LVP length, angle of the muscle origin, and cross-sectional area (CSA), measurements were obtained and compared between tasks.

RESULTS

Three of the 4 participants exhibited the expected patterns of change following concentric contraction of the LVP muscle. Consistent changes from the resting to the contracted state included reductions in LVP length by 13.5% and angle of the muscle origin by 9.8%, as well as increases in CSAs by 22.1%, on average.

CONCLUSIONS

This study presented high-resolution data of the LVP muscle behavior with the first in vivo 3-D measurements of the contracted LVP muscle, which can be useful for the validation of computational models that aim at describing biomechanical properties of the LVP muscle in future research. The active behavior of the extravelar LVP muscle also provides some insight on optimal LVP muscle geometry to consider during cleft palate repair.

Asymmetry and Positioning of the Levator Veli Palatini Muscle in Children With Repaired Cleft Palate

Purpose The purpose of this study is to examine the differences in velopharyngeal dimensions as well as levator veli palatini (levator) muscle morphology, positioning, and symmetry of children with repaired cleft palate with velopharyngeal insufficiency (VPI), children with repaired cleft palate with complete velopharyngeal closure, and children with noncleft anatomy. Method Fifteen children ranging in age from 4 to 8 years were recruited for this study. Ten of the participants had a history of repaired cleft palate, half with documented VPI and the other half with velopharyngeal closure. Five participants with noncleft anatomy were matched for age from a normative database. The magnetic resonance imaging protocol, processing methods, and analysis are consistent with that used in previous literature. Results Regarding velopharyngeal dimensions, median values were statistically significantly different between groups for sagittal angle (p = .031) and effective velopharyngeal ratio (p = .013). With respect to the levator muscle, median values were statistically significant for average extravelar length (p = .018), thickness at midline (p = .021), and thickness between the left and right muscle bundles at the point of insertion into the velum (p = .037). Remaining measures were not statistically significant. Conclusions The levator muscle is significantly different among these three groups with respect to thickness at midline, extravelar length, and symmetry at the point of insertion into the velum. Sagittal angle and effective velopharyngeal ratio are also significantly different. Participants with repaired cleft palate and VPI displayed the greatest degree of asymmetry. Future research should control for surgical procedure type to determine the impact of surgery on the levator muscle and surrounding velopharyngeal anatomy.

A Dynamic Magnetic Resonance Imaging-Based Method to Examine In Vivo Levator Veli Palatini Muscle Function During Speech

Purpose The aim of this study was to develop a method able to quantify levator veli palatini (LVP) muscle shortening and contraction velocities using dynamic magnetic resonance imaging (MRI) throughout speech samples and relate these measurements to velopharyngeal portal dimensions. Method Six healthy adults (3 men and 3 women, M = 24.5 years) produced syllables representing 4 different manners of production during real-time dynamic MRI scans. We acquired an oblique-coronal slice of the velopharyngeal mechanism, which captured the length of the LVP, and manually segmented each frame. LVP shortening and muscle velocities were calculated from the acquired images. Results Using our method, we found that subjects demonstrated greater LVP shortening and higher maximum contraction velocities during fricative and plosive syllable production than during nasal or vowel syllable production. LVP shortening and maximum contraction velocity positively correlated with velopharyngeal port depth. Conclusions In vivo LVP function differs between manners of production, as expected, and an individual's velopharyngeal portal dimensions influence LVP function. These measures, contextualized with the force-length and force-velocity muscle relationships, provide new insight into LVP function. Future studies could use this method to investigate LVP function in healthy speakers and individuals with velopharyngeal dysfunction and how function relates to velopharyngeal anatomy.

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.

Effects of Surgical Intervention and Continuous Positive Airway Pressure Therapy on Velopharyngeal Structure and Function: A Case Report

Changes to the velum and velopharyngeal muscles following Furlow double-opposing Z-plasty in a 7-year-old female with submucous cleft palate and velopharyngeal dysfunction (VPD) were evaluated. Perceptual, instrumental (ie, nasometry and aerodynamic pressure flow), and research magnetic resonance imaging analyses were used during pre- and postsurgical time points at a university research clinic. Continuous positive airway pressure (CPAP) therapy was trialed following a failed surgery for residual VPD in the patient. Increases in velar length and thickness and decreases in levator veli palatini muscle angle of origin and contraction were observed following the Furlow double-opposing Z-plasty surgery. Variable improvements in residual hypernasality following the home-based CPAP therapy protocol were observed.

Assessment of velopharyngeal function with dual-planar high-resolution real-time spiral dynamic MRI

PURPOSE

To develop a real-time dynamic MRI method for comprehensive evaluation of velum movement during speech.

METHODS

Dynamic MRI has been used to study velopharyngeal insufficiency (VPI) by imaging the movement of the velum during speech, because it can provide good anatomic details with no exposed radiation. To be able to comprehensively evaluate dynamic velum movement, a real-time spiral non-balanced SSFP sequence was developed with simultaneous dual-planar coverage and improved spatial and temporal resolution using a combination of parallel imaging and spatial and temporal compressed sensing to achieve 6 × acceleration. New off-resonance correction and post-processing methods were also developed to reduce blurring and slice crosstalk.

RESULTS

The method demonstrated good image quality for visualizing dynamic velum movement with reduced blurring and improved image homogeneity. Spatial resolution of 1.2*1.2 mm² with 150 mm FOV and temporal resolution of 20 frames-per-second with simultaneous dual-planar coverage was achieved.

CONCLUSIONS

This work describes a new technique for studying speech disorders using dual-planar accelerated spiral dynamic MRI.

Morphology of the Levator Veli Palatini Muscle in Adults With Repaired Cleft Palate

The purpose of this study was to examine differences in levator veli palatini (levator) morphology between adults with repaired cleft palate and adults with noncleft anatomy. Fifteen adult participants (10 with noncleft anatomy, 5 with repaired cleft palate) underwent 3-dimensional (3D) static magnetic resonance imaging (MRI). Image analyses included measures of total muscle volume and the circumference and diameter at 6 points along the length of the muscle. Differences between groups were analyzed using independent sample Mann-Whitney U tests (α < 0.05). Significant differences between groups were noted for measures of muscle volume, circumference at the origin and midline, anterior-posterior diameter at the origin and midline, and superior-inferior diameter at the point of insertion into the velum and midline. Differences in measures at other points along the levator muscle belly were not statistically significant. Limited sample size and gender differences may have impacted statistical findings. Overall, the levator muscle in adults with repaired cleft palate is significantly different than that of adults with noncleft anatomy. This study demonstrates the successful implementation of a method for 3D analysis of velopharyngeal (VP) musculature with potential clinical utility given continued technological advancements in MRI. Continued evaluation of pre- and postsurgical anatomy and short- and long-term outcomes may contribute to a better understanding of the effects of various types of palatoplasties on levator structure, which is important to VP function for speech.

Variations in Velopharyngeal Structure in Adults With Repaired Cleft Palate

OBJECTIVE

The purpose of this study was to examine differences in velopharyngeal structures between adults with repaired cleft palate and normal resonance and adults without cleft palate.

DESIGN

Thirty-six English-speaking adults, including 6 adults (2 males and 4 females) with repaired cleft palate (M = 32.5 years of age, SD = 17.4 years) and 30 adults (15 males and 15 females) without cleft palate (M = 23.3 years of age, SD = 4.1 years), participated in the study. Fourteen velopharyngeal measures were obtained on magnetic resonance images and compared between groups (cleft and noncleft).

RESULTS

After adjusting for body size and sex effects, there was a statistically significant difference between groups for 10 out of the 14 velopharyngeal measures. Compared to those without cleft palate, participants with repaired cleft palate had a significantly shorter hard palate height and length, shorter levator muscle length, shorter intravelar segment, more acute levator angles of origin, shorter and thinner velum, and greater pharyngeal depth.

CONCLUSION

Although significant differences were evident in the cleft palate group, individuals displayed normal resonance. These findings suggest that a wide variability in velopharyngeal anatomy can occur in the presence of normal resonance, particularly for those with repaired cleft palate. Future research is needed to understand how anatomic variability impacts function, such as during speech.

Magnetic Resonance Imaging of the Levator Veli Palatini Muscle in Speakers with Repaired Cleft Palate

Objective:

To obtain detailed anatomic and physiologic information on the levator veli palatini muscle from MRI in individuals with repaired cleft palate and to compare the results with those from normal subjects reported by Ettema et al. (2002).

Design:

Prospective study.

Setting:

University-based hospital.

Participants:

Four men (ages 22 to 43 years) with repaired cleft lip and palate.

Main Outcome Measures:

Four quantitative measurements of the levator veli palatini muscle from rest position and dynamic speech magnetic resonance images were obtained: the distance between the origins of the muscle, angle of origin of the muscle, muscle length, and muscle thickness.

Results:

The length and thickness of the levator veli palatini muscle varied among the subjects and were different from measurements obtained from normal subjects in a previous study. The distance between origin points, length, and thickness of the levator veli palatini muscle were smaller than those of the normal subjects. There were systematic changes of the levator veli palatini muscle, depending upon vowel and consonant types. Levator veli palatini muscle angle of origin and length became progressively smaller from rest, nasal consonants, low vowels, high vowels, and fricative consonants. These changes are consistent with those of the normal subjects.

Conclusions:

This study contributes to a better understanding of cleft palate anatomy in comparison with normal anatomy of the levator veli palatini muscle. The use of MRI shows promise as an important tool in the diagnosis and eventual aid to treatment decisions for individuals born with cleft palate.

Morphology of the Auditory Tube and Palatal Muscles in a Case of Bilateral Cleft Palate

Objective

There is an increased incidence of otitis media in children with cleft palate, which may be related to the pathology of the auditory tube and palatal muscles. In the present study, the head of a human on term born fetus with bilateral palatal cleft was serially sectioned and the anatomy of the auditory tube and palatal muscles were studied by computer-aided three-dimensional reconstruction.

Results

The results showed a nearly horizontal course of the auditory tube. The tensor veli palatini muscle had a bony attachment on either side. The levator veli palatini muscle also showed an abnormal course.

Conclusions

This abnormal course may result in obstruction of the auditory tube during contraction. These pathological findings may explain the higher frequency of otitis media in children with cleft palate.

Dynamic Analysis of Articulatory Movement Using Magnetic Resonance Imaging Movies: Methods and Implications in Cleft Lip and Palate

Objectives

To visualize articulatory movement using a magnetic resonance imaging (MRI) movie of a subject with cleft lip and palate (CLP) and to demonstrate the usefulness of this method for studying oropharyngeal function.

Material and Methods

Dynamic changes in oropharyngeal structures were assessed with an MRI movie of a man with cleft lip and palate and in a normal adult male volunteer during the articulation of /pa/, /ta/, and /ka/.

Results and Conclusions

Different movement patterns were observed during articulation in the subject with CLP compared with the normal volunteer. Posterosuperior movement of the tongue and the anterior movement of the posterior pharyngeal wall were clearly visualized in the subject with CLP. Thus, MRI movies appear to be a promising tool for evaluating speech function in patients with CLP because of their noninvasive and nonradiation nature.

Magnetic Resonance Imaging of the Levator Veli Palatini Muscle before and after Primary Palatoplasty

Objective

To explore the application of magnetic resonance imaging (MRI) in the evaluation of patients with cleft palate before and after primary palatoplasty with particular attention focused on the levator veli palatini muscle.

Design

Prospective study using MRIs of subjects before and after primary cleft palate surgery.

Setting

Hospital and university based.

Patients

One female infant with normal anatomy. Three male and four female infants with cleft palate of varying severity.

Intervention

Furlow double-opposing Z-plasty and V-Y palatoplasty.

Main Outcome Measures

Magnetic resonance images.

Results

It was found that the levator veli palatini muscle can be imaged before and after palatal surgery in infants using MRI. The muscle may have sufficient volume, proportionate to a normal infant or adult, in infants born with cleft palate. If retrodisplaced properly, the muscle is likely to be steeper (more vertical) from its origin at the base of the skull to its insertion into the velum following palatoplasty, thus providing a more favorable angle for elevating the velum. Following palatal surgery, the levator muscle mass may not be as cohesive across the velar midline, compared with normal musculature.

Conclusion

MRI is a viable imaging modality for the evaluation of the anatomy of the levator veli palatini muscle before and after primary palatoplasty in infants born with cleft palate.

Can Dynamic MRI Be Used to Accurately Identify Velopharyngeal Closure Patterns?

BACKGROUND

Dynamic magnetic resonance imaging (MRI) has been proposed as a non-invasive, child-friendly, reproducible, and repeatable imaging method providing a 3-dimensional view of the velopharyngeal structures and function during speech. However, the value of dynamic MRI as compared to imaging methods such as nasopharyngoscopy is not well understood. The aim of this study was to compare the ability of nasopharyngoscopy and dynamic MRI to accurately identify velopharyngeal closure patterns among adults without cleft palate.

METHODS

Participants included 34 healthy adults with normal anatomy between 19 and 33 years of age (mean = 23 years; SD = 4.1 years). Participants underwent dynamic MRI and nasopharyngoscopy studies and comparisons were performed to determine the intra- and inter-rater reliability for accurately determining closure pattern. The MRI acquisition was a dynamic acquisition of a 2D plane.

RESULTS

Strong inter- (κ = .824; P < .001) and intra-rater (Rater 1: κ = 0.879, P < .001, 94% agreement between ratings; Rater 2 with 100% agreement) agreement was observed for the identification of closure pattern using nasopharyngoscopy. Inter-rater agreement for ratings using MRI demonstrated moderate agreement (κ = .489; P < .004). Examining point agreement revealed only 27 of the 33 ratings of MRI showed agreement (80%).

CONCLUSION

This demonstrates that inter-rater reliability for determining closure patterns from nasopharyngoscopy is good; however, ratings using MRI was less reliable at determining closure patterns. It is likely that future improvements in dynamic imaging with MRI to enable 3D visualizations are needed for improved diagnostic accuracy for assessing velopharyngeal closure patterns.

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.

Clinical Significance of the Levator Veli Palatini Muscle in Velocardiofacial Syndrome Patients

Background:

Anatomical variation and deficits of velocardiofacial syndrome patients are related to unsatisfactory treatment results in surgical correction of speech abnormalities. The main purpose of the article is to investigate the clinical significance of thinned levator veli palatini muscle in VCFS patients.

Methods:

The authors reviewed medical records of all children with velocardiofacial syndrome who received pharyngeal flap surgery between March 2007 and September 2015. Data including thickness of levator veli palatini in magnetic resonance examination; preoperative velopharyngeal gap size from nasoendoscopy; and preoperative and postoperative speech outcomes were collected.

Results:

Total of 36 velocardiofacial syndrome patients with preoperative objective data and postoperative speech outcomes were identified. Preoperative velopharyngeal gap showed significant correlation with thickness of levator veli palatini (correlation coefficient: 0.297/0.397, P = .02/.03) and gap size showed correlation with postoperative speech improvement (0.347/0.413, P = .04/.02). However, muscle thickness showed no correlation with speech outcomes (0.046/0.037, P = .77/.86).

Conclusion:

Thinned levator veli palatini muscle in velocardiofacial syndrome patients are related to widened velopharyngeal gap and production of hypernasal speech, and can give negative impact on postoperative surgical outcome of pharyngeal flap surgery.

Normative Velopharyngeal Data in Infants: Implications for Treatment of Cleft Palate

Identifying normative data related to velopharyngeal muscles and structures may have clinical significance for infants born with cleft palate, especially as they relate to selection of surgical intervention and postsurgical outcomes. Previous studies suggest that patients whose anatomy postsurgically is dissimilar to that of their normative counterparts are at risk for hypernasal speech. However, studies have not documented what constitutes "normal" anatomy for the clinically relevant population-that is, the infant population. The purpose of this study is to examine a magnetic resonance imaging database (n = 29) related to normative velopharyngeal structures and provide a preliminary comparison to 2 selected patients with repaired cleft palate. Twenty-nine healthy infants between 9 and 23 months of age (mean = 15.2 months) with normal craniofacial and velopharyngeal anatomy were recruited to participate in this study. Normative data were compared to 2 infants with repaired cleft palate between 13 and 15 months of age (mean = 14 months). Quantitative craniometric and velopharyngeal measures from the sagittal and oblique coronal image planes were collected. Variables of interest included: levator muscle, velar, and craniometric measures. Females demonstrated significantly larger intravelar segments compared with males. White infants demonstrated significantly larger levator muscles compared to non-white infants. Infants with repaired cleft palate demonstrated increased overall levator muscle length and levator extravelar length compared with infants with normal velopharyngeal anatomy.Data from the present study provide a normative database for future investigators to utilize as a comparative tool when evaluating infants with normal and abnormal velopharyngeal anatomy.

Velopharyngeal Structural and Functional Assessment of Speech in Young Children Using Dynamic Magnetic Resonance Imaging

OBJECTIVE

The purpose of this study was to demonstrate a novel method for examining the velopharyngeal mechanism using static and dynamic magnetic resonance imaging (MRI) at the sentence-level production in young children with normal anatomy. This study examined whether velopharyngeal events occurring in the midsagittal plane are correlated to muscle events occurring along the plane of velopharyngeal closure. Adenoid involvement in velopharyngeal function was also explored.

METHODS

A high-resolution, T2-weighted turbo-spin-echo three-dimensional anatomical scan was used to acquire static velopharyngeal data and a fast-gradient echo fast low angle shot multishot spiral technique (15.8 frames per second) was used to acquire dynamic data on 11 children between 4 and 9 years old.

RESULTS

Changes in velar knee height from rest to the bilabial /p/ production was strongly correlated with changes in the velar configuration (r = 0.680, P = .021) and levator muscle contraction (r = 0.703, P = .016). Velar configuration was highly correlated to levator muscle changes (r = 0.685, P = .020). Mean alpha angle during bilabial /p/ production was 176°, which demonstrated that subjects achieve velopharyngeal closure at or just below the palatal plane. Subjects with a larger adenoid pad used significantly less (r = -0.660, P = .027) levator muscle contraction compared with individuals with smaller adenoids.

CONCLUSIONS

This study demonstrates a potentially useful technique in dynamic MRI that does not rely on cyclic repetitions or sustained phonation. This study lends support to the clinical potential of dynamic MRI methods for cleft palate management.

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.

A computational model of velopharyngeal closure for simulating cleft palate repair

The levator veli palatini (LVP) muscle has long been recognized as the muscle that contributes most to velopharyngeal (VP) closure and is therefore of principal importance for restoring normal speech in patients with a cleft palate. Different surgical reconstructive procedures can utilize varying degrees of LVP overlap, and this study developed a new finite-element model of VP closure designed to understand the biomechanical effects of LVP overlap. A three-dimensional finite-element model was created from adult anatomical dimensions and parameters taken from the literature. Velopharyngeal function was simulated and compared with experimental measurements of VP closure force from a previous study. Varying degrees of overlap and separation of the LVP were simulated, and the corresponding closure force was calculated. The computational model compares favorably with the experimental measurements of closure force from the literature. Furthermore, the model predicts that there is an optimal level of overlap that maximizes the potential for the LVP to generate closure force. The model predicts that achieving optimal overlap can increase closure force up to roughly 100% when compared with too little or too much overlap. The results of using this new model of VP closure suggest that optimizing LVP overlap may produce improved surgical outcomes due to the intrinsic properties of muscle. Future work will compare these model predictions with clinical observations and provide further insights into optimal cleft palate repair and other craniofacial surgeries.

Differences in Velopharyngeal Structure during Speech among Asians Revealed by 3-Tesla Magnetic Resonance Imaging Movie Mode

Objective. Different bony structures can affect the function of the velopharyngeal muscles. Asian populations differ morphologically, including the morphologies of their bony structures. The purpose of this study was to compare the velopharyngeal structures during speech in two Asian populations: Japanese and Thai. Methods. Ten healthy Japanese and Thai females (five each) were evaluated with a 3-Tesla (3 T) magnetic resonance imaging (MRI) scanner while they produced vowel-consonant-vowel syllable (/asa/). A gradient-echo sequence, fast low-angle shot with segmented cine and parallel imaging technique was used to obtain sagittal images of the velopharyngeal structures. Results. MRI was carried out in real time during speech production, allowing investigations of the time-to-time changes in the velopharyngeal structures. Thai subjects had a significantly longer hard palate and produced shorter consonant than Japanese subjects. The velum of the Thai participants showed significant thickening during consonant production and their retroglossal space was significantly wider at rest, whereas the dimensional change during task performance was similar in the two populations. Conclusions. The 3 T MRI movie method can be used to investigate velopharyngeal function and diagnose velopharyngeal insufficiency. The racial differences may include differences in skeletal patterns and soft-tissue morphology that result in functional differences for the affected structures.

A Computational Model Quantifies the Effect of Anatomical Variability on Velopharyngeal Function

PURPOSE

This study predicted the effects of velopharyngeal (VP) anatomical parameters on VP function to provide a greater understanding of speech mechanics and aid in the treatment of speech disorders.

METHOD

We created a computational model of the VP mechanism using dimensions obtained from magnetic resonance imaging measurements of 10 healthy adults. The model components included the levator veli palatini (LVP), the velum, and the posterior pharyngeal wall, and the simulations were based on material parameters from the literature. The outcome metrics were the VP closure force and LVP muscle activation required to achieve VP closure.

RESULTS

Our average model compared favorably with experimental data from the literature. Simulations of 1,000 random anatomies reflected the large variability in closure forces observed experimentally. VP distance had the greatest effect on both outcome metrics when considering the observed anatomic variability. Other anatomical parameters were ranked by their predicted influences on the outcome metrics.

CONCLUSIONS

Our results support the implication that interventions for VP dysfunction that decrease anterior to posterior VP portal distance, increase velar length, and/or increase LVP cross-sectional area may be very effective. Future modeling studies will help to further our understanding of speech mechanics and optimize treatment of speech disorders.

High-resolution dynamic speech imaging with joint low-rank and sparsity constraints

PURPOSE

To enable dynamic speech imaging with high spatiotemporal resolution and full-vocal-tract spatial coverage, leveraging recent advances in sparse sampling.

METHODS

An imaging method is developed to enable high-speed dynamic speech imaging exploiting low-rank and sparsity of the dynamic images of articulatory motion during speech. The proposed method includes: (a) a novel data acquisition strategy that collects spiral navigators with high temporal frame rate and (b) an image reconstruction method that derives temporal subspaces from navigators and reconstructs high-resolution images from sparsely sampled data with joint low-rank and sparsity constraints.

RESULTS

The proposed method has been systematically evaluated and validated through several dynamic speech experiments. A nominal imaging speed of 102 frames per second (fps) was achieved for a single-slice imaging protocol with a spatial resolution of 2.2 × 2.2 × 6.5 mm(3) . An eight-slice imaging protocol covering the entire vocal tract achieved a nominal imaging speed of 12.8 fps with the identical spatial resolution. The effectiveness of the proposed method and its practical utility was also demonstrated in a phonetic investigation.

CONCLUSION

High spatiotemporal resolution with full-vocal-tract spatial coverage can be achieved for dynamic speech imaging experiments with low-rank and sparsity constraints.

Effects of Gravity on the Velopharyngeal Structures in Children Using Upright Magnetic Resonance Imaging

Objective

The influence of gravity on the velopharyngeal structures in children is unknown. The purpose of this study is to compare the velopharyngeal mechanism in the upright and supine positions while at rest and during sustained speech production in children between 4 and 8 years old.

Methods

A 0.6 Tesla open-type, multipositional magnetic resonance imaging scanner was used to image subjects in the upright and supine positions. The scanning protocol included a T2 fluid attenuation inversion recovery and an oblique coronal turbo spin echo scan with short scanning durations (7.9 seconds) to enable visualization of the velopharyngeal anatomy during rest and production of sustained /i/ and /s/.

Results

The magnetic resonance imaging protocol used for this study enabled successful visualization of the velopharyngeal anatomy in the sagittal and oblique coronal planes at rest and during sustained phonation of /i/ and /s/. Positional differences demonstrated a small nonsignificant ( P > .05) variation for velar measures (length, thickness, and height), retrovelar space, and levator veli palatini measures (length and angles of origin).

Conclusions

Gravity had a negligible effect on velar length, velar thickness, velar height, retrovelar space, levator muscle length, and levator angles of origin. Supine imaging data can be translated to an upright activity such as speech. This is the first study to provide normative levator muscle lengths for children between 4 and 8 years old. Upright imaging may be a promising tool for difficult-to-test populations.

Anthropometric Analysis of the Velopharynx and Related Craniometric Dimensions in Three Adult Populations Using MRI

OBJECTIVE

The purpose of this study is to examine effects of sex, race, and craniometry among three distinct racial groups of adults with normal velopharyngeal anatomy and to determine whether craniofacial structures could be used to predict velopharyngeal structures.

METHODS

A total of 88 adults across three racial groups including white, black, and Asian (Japanese) participated. Magnetic resonance images were obtained using a high-resolution, three-dimensional anatomical scan. Measurements were obtained on the levator veli palatini muscle, velum, and craniofacial structures.

RESULTS

Head circumference was used as a covariate to control the effect of overall cranial size on the analyses. Palate height, linear cranial base, and face height and width vary based on sex, with men demonstrating larger values compared with women. Linear base values, cranial base angle, and face width vary significantly based on race, with Japanese subjects showing the smallest anterior to posterior measures and larger face-width values. Levator muscle measures, excluding angle measures, vary significantly (P < .0001) based on sex. There was no statistically significant difference (P > .05) among racial groups in the levator muscle measures. Velar length and thickness varied significantly based on race and sex.

CONCLUSIONS

This is the first study to examine the interaction of race and sex on levator muscle morphology. In spite of the differences in velar dimensions, no significant differences were found in muscle size, specifically the levator veli palatini, which is contained within the velum.

Magnetic Resonance Imaging of Velar Muscle Tissue Distribution in Healthy Adults

OBJECTIVES

To examine muscle tissue distribution along the length of the velum in living individuals using magnetic resonance imaging (MRI).

DESIGN

Using the three-dimensional MRI data acquired from 10 normal white adults, two area measures including the muscular area and the total velar area were obtained from 10 oblique slices running perpendicular to velar length. A polynomial regression analysis was performed where the proportion of the muscular to the total velar area was regressed on the slice numbers running along the length of the velum.

RESULTS

The proportion of the muscular to total velar area increased from the anterior section of the velum, reaching a maximum (33.24%) in the midsection, and decreasing in the posterior section of the velum. A third-order (cubic) polynomial function that best illustrated the proportional data (R(2) = .47) was derived.

CONCLUSIONS

The present study demonstrated that MRI is a viable tool to examine the muscle tissue distribution of the velum in living individuals. Although the overall pattern in the muscle tissue distribution of the healthy velum was similar to that reported in previous literature based on cadaver specimens, the participants in the present study appeared to have greater muscular proportion of the velum. The muscular proportion measure derived from the healthy living individuals can be used as an additional parameter accounting for sufficient intravelar muscle mass for future studies.

Sexual dimorphism of the levator veli palatini muscle: an imaging study

Objective : Magnetic resonance imaging studies of the levator veli palatini muscle have used small numbers of subjects and have not consistently controlled for sex, race, or age. The purpose of this study was to conduct a structural assessment using a large homogeneous sample to examine the sex differences in the levator muscle morphology. Methods : Thirty white adult subjects (15 men and 15 women) were imaged using a 3 Tesla MRI system. A high-resolution SPACE (sampling perfection with application-optimized contrasts using different flip-angle evolution) sequence was used to acquire images of the velopharyngeal anatomy. Levator muscle measurements were obtained. Results : Men displayed significantly greater levator extravelar segment length (P = .003), levator intravelar segment muscle length (P < .001), greater distance between levator insertion points (P < .001), and greater angles of origin (P = .008) compared with women. There was no statistically significant variation between men and women in the distance between points of origin at the base of the skull. Conclusions : This study provides normative data to improve understanding of levator dysmorphology such as that in cleft palate muscle anatomy. Results of the study demonstrate significant differences between white men and women across several levator muscle measures. Variations in the relative size of the cranium or height of the individual were not proportionate to the variations observed in the levator muscle.

Speech function of the oropharyngeal isthmus: A modeling study

A finite element method (FEM) based numerical model of upper airway structures (jaw, tongue, maxilla, soft palate) was implemented to observe interactions between the soft palate and tongue, and in particular to distinguish the contributions of individual muscles in producing speech-relevant constrictions of the oropharyngeal isthmus (OPI), or "uvular" region of the oral tract. Simulations revealed a sphincter-like general operation for the OPI, particularly with regard to the function of the palatoglossus muscle. Further, as has been observed with the lips, the OPI can be controlled by multiple distinct muscular mechanisms, each reliably producing a different sized opening and robust to activation noise, suggestive of a modular view of speech motor control. As off-midline structures of the OPI are difficult to observe during speech production, biomechanical simulation offers a promising approach to studying these structures.

Using MRI for assessing velopharyngeal structures and function

OBJECTIVE

Direct visualization of the velopharynx and, in particular, the levator muscle is particularly important in the assessment of velopharyngeal function and normal speech production. The purpose of this study is to demonstrate the development of a static and dynamic magnetic resonance imaging protocol for evaluation of velopharyngeal structures and function.

METHODS

A high-resolution, T2-weighted turbo-spin-echo three-dimensional anatomical scan (sampling perfection with application optimized contrasts using different flip angle evolution) was used to acquire a large field of view covering the velopharyngeal anatomy. Dynamic speech assessment was obtained using a fast-gradient echo, fast low-angle shot, multi-shot spiral technique to acquire 15.8 frames per second (FPS) of the sagittal and oblique coronal image planes.

RESULTS

Using a three-dimensional data set, as opposed to two-dimensional data, the full contour of the levator muscle can be appreciated. Dynamic images were obtained at 15.8 FPS in the sagittal and oblique coronal planes, enabling visualization of the movements of the velum, posterior pharyngeal wall, lateral pharyngeal walls, and levator muscle during speech.

CONCLUSIONS

A three-dimensional magnetic resonance imaging sequence, such as that used in the present study, may provide better analyses and more precise measurements. A dynamic fast low-angle shot sequence allows for visualization of the levator muscle and the velum during speech at a high image rate. This protocol could have a significant impact in improving the process of visualizing pathology and promoting clinical treatment plans for individuals born with cleft lip and palate.

Morphology of the levator veli palatini muscle using magnetic resonance imaging

Background : No studies have reported the circumference and diameter of the levator veli palatini muscle at multiple points along its length and from both views (frontal and lateral). The purpose of this study was to provide quantitative data regarding the levator muscle morphology along the length of the muscle using magnetic resonance imaging and advanced three-dimensional computer technology. Methods : Ten Caucasian male subjects participated in the study. Subjects were scanned using a Siemens 3 T Trio. Levator muscle measures were obtained using a two-dimensional image plane. A three-dimensional model was used to measure the circumference and muscle diameter (in two directions) at six points along the length of the levator muscle. Results : Levator muscle length ranged from 41.67 mm to 52.85 mm across all subjects. Mean extravelar muscle length was 30.55 mm (SD, 2.8 mm) and 30.01 mm (SD, 2.9 mm) for right and left muscles. The mean circumference at the origin was 18.90 mm (SD, 2.6 mm). At the second point, the muscle circumference mean increased slightly (mean, 22.40 mm; SD, 4.9 mm). The means for the remainder of the measures (points 3, 4, 5, and 6) were consistent, showing little to no change. Conclusion : Circumference and diameter values were similar to those reported in previous literature. The muscle did diverge at the point where the muscle bundle entered the velum, as it has been previously described. Instead, the muscle diverges near the midline insertion becoming sparser (smaller superior-to-inferior diameter).

Towards clinical assessment of velopharyngeal closure using MRI: evaluation of real-time MRI sequences at 1.5 and 3 T

OBJECTIVE

The objective of this study was to demonstrate soft palate MRI at 1.5 and 3 T with high temporal resolution on clinical scanners.

METHODS

Six volunteers were imaged while speaking, using both four real-time steady-state free-precession (SSFP) sequences at 3 T and four balanced SSFP (bSSFP) at 1.5 T. Temporal resolution was 9-20 frames s(-1) (fps), spatial resolution 1.6 × 1.6 × 10.0-2.7 × 2.7 × 10.0 mm(3). Simultaneous audio was recorded. Signal-to-noise ratio (SNR), palate thickness and image quality score (1-4, non-diagnostic-excellent) were evaluated.

RESULTS

SNR was higher at 3 T than 1.5 T in the relaxed palate (nasal breathing position) and reduced in the elevated palate at 3 T, but not 1.5 T. Image quality was not significantly different between field strengths or sequences (p=NS). At 3 T, 40% acquisitions scored 2 and 56% scored 3. Most 1.5 T acquisitions scored 1 (19%) or 4 (46%). Image quality was more dependent on subject or field than sequence. SNR in static images was highest with 1.9 × 1.9 × 10.0 mm(3) resolution (10 fps) and measured palate thickness was similar (p=NS) to that at the highest resolution (1.6 × 1.6 × 10.0 mm(3)). SNR in intensity-time plots through the soft palate was highest with 2.7 × 2.7 × 10.0 mm(3) resolution (20 fps).

CONCLUSIONS

At 3 T, SSFP images are of a reliable quality, but 1.5 T bSSFP images are often better. For geometric measurements, temporal should be traded for spatial resolution (1.9 × 1.9 × 10.0 mm(3), 10 fps). For assessment of motion, temporal should be prioritised over spatial resolution (2.7 × 2.7 × 10.0 mm(3), 20 fps). Advances in knowledge Diagnostic quality real-time soft palate MRI is possible using clinical scanners and optimised protocols have been developed. 3 T SSFP imaging is reliable, but 1.5 T bSSFP often produces better images.

Application of the International Classification of Functioning, Disability, and Health–Children and Youth Version (ICF-CY) to Cleft Lip and Palate

Objective

In recent health policy discussions, the World Health Organization has urged member states to implement the International Classification of Functioning, Disability, and Health: Children and Youth Version in their clinical practice and research. The purpose of this study was to identify codes from the International Classification of Functioning, Disability, and Health: Children and Youth Version relevant for use among children with cleft lip and/or palate, thereby highlighting the potential value of these codes for interprofessional cleft palate-craniofacial teams.

Design

The scope of recent published research in the area of cleft lip and/or palate was reviewed and compared with meaningful terms identified from the International Classification of Functioning, Disability, and Health: Children and Youth Version. In a five-step procedure, a consensus-based list of terms was developed that was linked separately to International Classification of Functioning, Disability, and Health: Children and Youth Version categories and codes. This provided a first draft of a core set for use in the cleft lip and/or palate field.

Conclusions

Adopting International Classification of Functioning, Disability, and Health: Children and Youth Version domains in cleft lip and/or palate may aid experts in identifying appropriate starting points for assessment, counseling, and therapy. When used as a clinical tool, it encourages health care professionals to go beyond treatment and outcome perspectives that are focused solely on the child and to include the children's environment and their familial/societal context. In order to establish improved, evidence-based interdisciplinary treatments for children with cleft lip and/or palate, more studies are needed that seek to identify all the influencing conditions of activities, children's participation, and barriers/facilitators in their environments.

Three-dimensional magnetic resonance imaging of velopharyngeal structures

PURPOSE

To report the feasibility of using a 3-dimensional (3D) magnetic resonance imaging (MRI) protocol for examining velopharyngeal structures. Using collected 3D MRI data, the authors investigated the effect of sex on the midsagittal velopharyngeal structures and the levator veli palatini (levator) muscle configurations.

METHOD

Ten Caucasian healthy adults (5 women and 5 men) participated. A whole-head 3D MRI scan was obtained while participants were at rest in the supine position. Basic anatomic parameters of the velopharynx including midsagittal velopharyngeal structures and levator muscle configurations were compared between sexes.

RESULTS

Detailed information on the 3D MRI protocol and data analysis method was introduced in the study. On the basis of the data, only the length of the levator muscle showed a statistically significant sex difference: Male participants had significantly longer levator muscles than those of female participants.

CONCLUSIONS

The present study successfully demonstrated the use of 3D MRI in quantifying major velopharyngeal structures and provided additional data on the anatomic variations that exist in healthy adult individuals.

Using magnetic resonance imaging for early assessment of submucous cleft palate: a case report

Surgical correction for submucous cleft palate is generally indicated in the presence of velopharyngeal inadequacy. Clinical assessment of velopharyngeal inadequacy requires that the child is able to produce a connected speech sample, which can yield a delay in treatment decisions that extends through a critical period of speech and language development. A perceptual speech assessment and intraoral examination are traditionally the most important methods of establishing a diagnosis of submucous cleft palate. The purpose of this case report is to demonstrate the use of magnetic resonance imaging as a diagnostic tool to provide early identification and an indication of surgical treatment for an individual born with a submucous cleft palate. The magnetic resonance images indicated a discontinuous levator veli palatini muscle sling arrangement with attachment of the muscle bundles onto the hard palate. Surgery was performed at 16 months and postsurgical speech evaluations demonstrated normal resonance and age-appropriate speech.