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

Does Notching Along the Nasal Velar Surface During Nasopharyngoscopy Predict Discontinuity of the Underlying Levator Veli Palatini Muscle?

To determine the sensitivity and specificity of velar notching seen on nasopharyngoscopy for levator veli palatini (LVP) muscle discontinuity and anterior positioning.

Nasopharyngoscopy and MRI of the velopharynx were performed on patients with VPI as part of their routine clinical care. Two speech-language pathologists independently evaluated nasopharyngoscopy studies for the presence or absence of velar notching. MRI was used to evaluate LVP muscle cohesiveness and position relative to the posterior hard palate. To determine the accuracy of velar notching for detecting LVP muscle discontinuity, sensitivity, specificity, and positive predictive value (PPV) were calculated.

A craniofacial clinic at a large metropolitan hospital.

PARTICIPANTS

Thirty-seven patients who presented with hypernasality and/or audible nasal emission on speech evaluation and completed nasopharyngoscopy and velopharyngeal MRI study as part of their preoperative clinical evaluation.

Among patients with partial or total LVP dehiscence on MRI, presence of a notch accurately identified discontinuity in the LVP 43% (95% CI 22-66%) of the time. In contrast, the absence of a notch accurately indicated LVP continuity 81% (95% CI 54-96%) of the time. The PPV for the presence of notching to identify a discontinuous LVP was 78% (95% CI 49-91%). The distance from the posterior edge of the hard palate to the LVP, known as effective velar length, was similar in patients with and without notching (median 9.8 mm vs 10.5 mm, P = 1.00).

The observation of a velar notch on nasopharyngoscopy is not an accurate predictor of LVP muscle dehiscence or anterior positioning.

Establishing a Clinical Protocol for Velopharyngeal MRI and Interpreting Imaging Findings

Traditional imaging modalities used to assess velopharyngeal insufficiency (VPI) do not allow for direct visualization of underlying velopharyngeal (VP) structures and musculature which could impact surgical planning. This limitation can be overcome via structural magnetic resonance imaging (MRI), the only current imaging tool that provides direct visualization of salient VP structures. MRI has been used extensively in research; however, it has had limited clinical use. Factors that restrict clinical use of VP MRI include limited access to optimized VP MRI protocols and uncertainty regarding how to interpret VP MRI findings. The purpose of this paper is to outline a framework for establishing a novel VP MRI scan protocol and to detail the process of interpreting scans of the velopharynx at rest and during speech tasks. Additionally, this paper includes common scan parameters needed to allow for visualization of velopharynx and techniques for the elicitation of speech during scans.

Magnetic Resonance Imaging for Assessing Velopharyngeal Function: Current Applications, Barriers, and Potential for Future Clinical Translation in the United States

OBJECTIVE

The use of magnetic resonance imaging (MRI) in the assessment process for children with cleft/craniofacial conditions remains uncommon, particularly for velopharyngeal assessments. The purpose of this study was to analyze the perceived clinical utility of MRI for cleft/craniofacial providers and identify barriers that exist for clinical translation of this imaging modality to this population of patients.

METHODS

A 38-item survey was disseminated to craniofacial team providers. Workplace context and demographics, MRI as a research and clinical tool, access and barriers for use of MRI, and needs for successfully establishing MRI protocols at clinical sites were investigated. Descriptive statistics were used to identify differences in the clinical use of MRI across disciplines. Chi-square analyses were conducted to determine how different specialties perceived potential barriers.

RESULTS

Respondents reported that MRI is likely to be beneficial for clinical assessments (93.5%) and that this imaging modality is available for use (83.8%). However, only 11.8% of providers indicated the use of MRI in their clinical assessments. This discrepancy highlights a potential disconnect between perceived use and implementation of this imaging methodology on cleft and craniofacial teams. A number of barriers were identified by providers. Challenges and opportunities for clinical translation of MRI protocols were highlighted.

CONCLUSION

Results may guide the development for improved clinical feasibility and implementation of MRI for clinical planning in this population of patients. Reported barriers highlight additional areas for translational research and the potential for the development of clinical tools related to MRI assessment and protocol implementation.

Measurement Matters: MRI Analysis of Differing Anatomic Measurement Techniques for Velar Length and the Velopharyngeal Needs Ratio

Background

Advances in imaging tools provide opportunities to enhance how velopharyngeal (VP) variables are quantified to facilitate surgical decisions. The purpose of this study was to use magnetic resonance imaging (MRI) to determine if quantitative differences were present between measures of linear and curvilinear velar length, and subsequently, the VP needs ratio.

Methods

Data were prospectively collected from patients presenting with repaired cleft palate and/or congenital palatal insufficiency with or without VPI at a single center tertiary children's hospital. Quantitative measures of the velopharynx using a novel nonsedated MRI protocol were obtained. Paired samples t tests were conducted to assess if differences were present between the VP needs ratio and measurements of linear and curvilinear velar length at rest and during sustained phonation. Intraclass correlation coefficients were calculated to assess intra/inter-rater reliability.

Results

Significant differences were present between measurements of linear and curvilinear velar length at rest (P ≤ 0.001) and during sustained phonation (P ≤ 0.001). Significant differences were also present in the VP needs ratio (P ≤ 0.001). Curvilinear velar length at rest and during sustained phonation was longer than that of linear velar length at rest and during sustained phonation. No significant differences were observed between measures of effective velar length (P = 0.393).

Conclusions

Measurement differences influence the VP needs ratio. This may have implications for comparisons to previously reported normative reference values and for those who are anatomically at risk for VPI. MRI provides an enhanced imaging modality to assess normative benchmarks and the anatomic variables used to define VP anatomy for clinical decision-making.

The Pediatric Neuroradiologist's Practical Guide to Capture and Evaluate Pre- and Postoperative Velopharyngeal Insufficiency

Up to 30% of children with cleft palate will develop a severe speech disorder known as velopharyngeal insufficiency. Management of velopharyngeal insufficiency typically involves structural and functional assessment of the velum and pharynx by endoscopy and/or videofluoroscopy. These methods cannot provide direct evaluation of underlying velopharyngeal musculature. MR imaging offers an ideal imaging method, providing noninvasive, high-contrast, high-resolution imaging of soft-tissue anatomy. Furthermore, focused-speech MR imaging techniques can evaluate the function of the velum and pharynx during sustained speech production, providing critical physiologic information that supplements anatomic findings. The use of MR imaging for velopharyngeal evaluation is relatively novel, with limited literature describing its use in clinical radiology. Here we provide a practical approach to perform and interpret velopharyngeal MR imaging examinations. This article discusses the velopharyngeal MR imaging protocol, methods for interpreting velopharyngeal anatomy, and examples illustrating its clinical applications. This knowledge will provide radiologists with a new, noninvasive tool to offer to referring specialists.

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.

Clinical efficacy of Hogan posterior pharyngeal flap in repairing velopharyngeal insufficiency secondary to cleft palate in older patients

OBJECTIVES

The clinical effects and surgical procedures of Hogan posterior pharyngeal flap in the treatment of the older patients with velopharyngeal insufficiency (VPI) after cleft palate repair were investigated.

METHODS

A total of 33 patients (aged 10-35 years; average of 20.4 years) with VPI secondary to cleft palate were included. They underwent Hogan posterior pharyngeal flap to improve velopharyngeal closure function. The clinical efficacy of the ope-ration was evaluated with Chinese speech clarity measurement and nasopharyngeal fiberscope (NPF), and the velopharyngeal closure was graded. The average follow-up time was 13.3 months.

RESULTS

The wounds of all patients were healed by first intention, and speech assessment showed that the consonant articulation increased and the rate of hypernasality and nasal emission decreased significantly (P<0.05). NPF examination showed that the postoperative velopharyngeal closure function significantly improved, 30 cases (91%) were gradeⅠ, and 3 cases (9%) were grade Ⅱ.

CONCLUSIONS

Hogan posterior pharyngeal flap for VPI secondary to cleft palate can significantly improve velopharyngeal closure.

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.

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.

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.

A Midsagittal-View Magnetic Resonance Imaging Study of the Growth and Involution of the Adenoid Mass and Related Changes in Selected Velopharyngeal Structures

PURPOSE

The adenoids, or pharyngeal tonsils, consist of a pad of lymphoid tissue, located on the posterior pharyngeal wall of the nasopharynx. During childhood, the adenoid pad serves as a contact site for the soft palate to assist with velopharyngeal closure during oral speech. During adenoidal involution, most children are able to maintain appropriate velopharyngeal closure necessary for normal speech resonance. The purpose of this study is to determine age-related trends of normal adenoid growth and involution from infancy through adulthood.

METHOD/DESCRIPTION

Lateral view magnetic resonance imaging was used to analyze velopharyngeal variables among 270 participants, between 3 months and 34 years of age. The velopharyngeal measures of interest included velar length, effective velar length, pharyngeal depth, adenoid height, adenoid thickness, adenoid depth, and adenoid area. Participants were divided into four age groups for statistical comparison.

RESULTS

There was a statistically significant difference (p < .05) in all linear and area measurements between the four age groups. Adenoid depth reached peak growth at age 4 years, whereas adenoid height and adenoid thickness peaked at 8 years of age. Qualitatively, adenoid growth progresses in an anterior and inferior direction whereas involution occurs in a posterior and superior direction.

CONCLUSIONS

This study contributes to the knowledge of time specific changes across an age span for adenoid growth and involution and presents a visualization of the shape and growth trends of adenoids. A new sequence of involution is reported beginning first with adenoid depth, followed by adenoid height at a slightly faster rate than adenoid thickness.