Effect of Velopharyngeal Gap Size on Laryngeal Morphology and Vocal Function in Children With VPI

September 22, 2026 updated by: Aya Atef Abdul-monem, Assiut University

Effect of Velopharyngeal Gap Size on Laryngeal Morphology and Vocal Function in Children With Velopharyngeal Insufficiency

Speech production relies on the precise coordination of the respiratory, phonatory, resonatory, and articulatory systems

. The velopharyngeal mechanism is essential in separating the oral and nasal cavities during speech and swallowing. Disruption of this mechanism leads to velopharyngeal insufficiency (VPI), which is characterized by the inability to achieve complete velopharyngeal closure due to structural or anatomical deficits. VPI is frequently associated with cleft palate, either repaired or unrepaired. It may also occur secondary to submucous cleft palate (CP), craniofacial syndromes, short palate, or post-adenoidectomy.

Study Overview

Status

Not yet recruiting

Conditions

Velopharyngeal Insufficiency

Detailed Description

Although the primary communication problem in VPI is a resonance disorder, persistent velopharyngeal insufficiency may alter normal vocal behavior. To compensate for the loss of intraoral pressure, many children with VPI develop excessive laryngeal muscle tension, increased respiratory effort, abnormal vocal fold adduction, or other compensatory phonatory behaviors. Over time, this laryngeal hyperfunction and other compensatory behaviors may result in muscle tension dysphonia and cause morphological changes of the vocal folds, such as vocal nodules, inflammation, and edema.

The reported prevalence of voice disorders in VPI patients ranges widely, from 5.5% based on a retrospective parent-reported hoarseness questionnaire to 72% in a prospective study employing perceptual voice assessment. This wide disparity primarily reflects methodological differences-such as indirect parental report versus direct perceptual evaluation, retrospective versus prospective designs, and heterogeneous patient samples-that profoundly influence prevalence estimates. Individuals with VPI may exhibit chronic hoarseness, forced, soft, strangled, or aspirated phonation. Additionally, children with CP ± lip (L) often have higher F0, jitter, and shimmer in their voices compared to typically developing children. Aydinli et al. have also shown that children with CP ± L who use glottal stops as a compensatory articulation strategy tend to have higher F0, shimmer, and jitter, indicating increased tension in their vocal cords affecting vocal fold vibration. Vocal nodules were the most common anatomical finding among individuals with CP and CP/L.

The relationship between VPI severity and concomitant voice disorders has been the subject of abundant investigation, yet studies across all assessment modalities have yielded inconsistent results. At the subjective level, Deengam et al. reported a correlation between hypernasality severity and perceptual voice disorder ratings, whereas Fujiki and Thibeault found that children with severe hypernasal resonance were 78% less likely to present with laryngeal pathology. Further adding to the discrepancy, Hamming et al., using a history of speech surgery as an indicator for VPI severity in a retrospective design, found no significant association between VPI and hoarseness, suggesting that voice abnormalities may persist independently of severity.

In an effort to resolve these inconsistencies, objective instrumental techniques-particularly nasoendoscopy-have been employed for precise VPI severity evaluation. However, reliance on the velopharyngeal closure pattern alone (e.g., closing, inconsistent, open) has not clarified the picture: D'Antonio et al. found no relationship between laryngeal/voice findings and velopharyngeal function, while McWilliams et al. reported that children with a borderline closure mechanism were more susceptible to voice changes. These persistent vocal abnormalities likely reflect chronic compensatory behaviors and laryngeal tissue changes driven by the pre-repair aerodynamic deficit, meaning a dynamic closure pattern does not reliably capture the cumulative vocal load imposed by the condition.

A more direct anatomical metric-the velopharyngeal gap (VPG) size-should theoretically be a better predictor. Yet here too, findings diverge: Lehes et al. observed no significant association between VPI severity and acoustic voice parameters, implying that increasing gap size does not necessarily correlate with voice quality, while Villafuerte-Gonzalez et al. reported abnormal acoustic measures, including elevated shimmer, specifically in cases with moderate VPG. Critically, both VPG size studies were limited by extremely small sample sizes (≤18 patients), severely constraining generalizability and statistical power. Thus, the contradictory evidence across subjective and objective measures-including the most direct anatomical index-underscores a fundamental gap in the literature and highlights the urgent need for a large-scale, adequately powered investigation that systematically quantifies velopharyngeal gap size via nasoendoscopy and rigorously examines its correlation with both subjective and objective voice outcomes.

Study Type

Observational

Enrollment (Estimated)

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Name: Aya A Abdulmonem, Resident
Phone Number: +201012667957
Email: aya.atef693@gmail.com

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

4 years to 12 years (Child)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Children aged 4-12 years with confirmed velopharyngeal insufficiency (VPI) will be consecutively recruited from the Phoniatric Unit, ENT Department, Assiut University Hospital. Participants will include children with non-syndromic cleft palate with or without cleft lip and children with VPI due to other cleft or non-cleft causes. Participants will be classified according to velopharyngeal gap size into small/near-complete, moderate, and large gap groups (23 children per group). An age- and sex-matched control group of 23 children without VPI or voice disorders will also be included (total planned sample: 92).

Description

Inclusion Criteria:

Children aged 4 to 12 years.
Non-syndromic cleft palate ± lip.
Confirmed diagnosis of velopharyngeal insufficiency due to cleft or non-cleft causes.
Cooperative children who are free from hearing, cognitive, and neuropsychiatric deficiencies.
Written informed consent from the parent/guardian and child assent where applicable.

Exclusion Criteria:

Previous secondary palatal speech surgery, including pharyngeal flap or sphincter pharyngoplasty.
Palatal fistula >2 mm that may affect velopharyngeal gap measurements.
Acute upper respiratory infection.
Severe allergic rhinitis.
Severe uncontrolled laryngopharyngeal reflux.
Voice overuse or vocal abuse within the preceding 2 weeks.
Congenital or acquired laryngeal disease, including traumatic, inflammatory, neoplastic, or endocrinological disease.

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Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Observational Models: COHORT
Time Perspectives: PROSPECTIVE

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
Small/near complete VP gap
Moderate VP gap
Large VP gap
Age and sex matched control group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subjective measurements of severity of dysphonia Time Frame: At baseline assessment	Measurements of vocal characteristics by a modified GRBAS scale, with 4 grades from 0 (normal) to 3 (severe dysphonia) known as GSLBI =overall grade (G), strained (S), leaky (L), breathy (B), and irregular (I).	At baseline assessment
Subjective measurements of patient's assessment of voice impairment severity Time Frame: At baseline assessment	Measurements of scores of Arabic pediatric voice handicap index (APVHI) Minimum value: Zero , Maximum value: 92 Higher scores means worse outcomes	At baseline assessment
Subjective measurements of adequacy of velopharyngeal port Time Frame: At baseline assessment	Number of participants with hypernasality and nasal air emission by simple clinical tests (Gutzman a/i test and Crezmerk cold mirror test)	At baseline assessment
Objective measurements of velopharyngeal gap quantification Time Frame: At baseline assessment	Measurements of velopharygeal gap size as a relative ratio of the persistent open area (in pixels) during maximum phonation divided by the total available portal area at rest (in pixels) with the aid of ImageJ software (version 1.52a, National Institutes of Health, USA) by using flexible nasofiberoscopy	At baseline assessment
Objective measurement of elements of hyperfunction Time Frame: At baseline assessment	Number of participants with anteroposterior and lateral pharyngeal compression, number of participants with vocal fold nodules, number of participants with edema or mucosal thickening by videostroboscopic examination There is no definite score, we will only detect the number of patients with these findings There are no multiple assessments with different units of measure	At baseline assessment
Objective measurements of vocal pitch Time Frame: At baseline assessment	Measurements of acoustic analysis: Fundamental frequency (Hz)	At baseline assessment
Objective measurements of vocal waveform frequency aperiodicity Time Frame: At baseline assessment	Measurements of acoustic analysis: Jitter (%)	At baseline assessment
Objective measurements of vocal waveform amplitude aperiodicity Time Frame: At baseline assessment	Measurements of acoustic analysis: Shimmer (dB)	At baseline assessment
Objective measurements of vocal waveform periodicity to aperiodicity ratio Time Frame: At baseline assessment	Measurements of acoustic analysis: Harmonic to noise ratio (dB)	At baseline assessment
Objective measurements of laryngeal function and glottal insufficiency Time Frame: At baseline assessment	Measurements of aerodynamic parameter: Maximum phonation time (seconds)	At baseline assessment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Assiut University

Investigators

Study Chair: Essam M Aref, Prof, Phoniatrics Department, Assiut University Hospital
Study Chair: Nada A Kamel, Lecturer, Phoniatrics Department, Assiut University Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 25, 2026

Primary Completion (Estimated)

September 1, 2027

Study Completion (Estimated)

September 1, 2028

Study Registration Dates

First Submitted

September 16, 2026

First Submitted That Met QC Criteria