Keywords Cleft Palate - Communication Disorders - Velopharyngeal Sphincter
Introduction
The velopharyngeal mechanism relies on the action of the velopharyngeal sphincter
to control the distribution of voiced and voiceless airstream in both the oral cavity
and the nasal cavity. Individuals with an impaired velopharyngeal mechanism will develop
velopharyngeal dysfunction (VPD), which may compromise the verbal communication skills
of patients with an intact velopharyngeal sphincter (VPS). One of the consequences
of such dysfunction is hypernasality, which has a great impact on the individuals
with this condition.
Hypernasality induces nasal resonance in sounds that should not have this characteristic
in articulate speech. This is caused by excessive nasal air emissions and weak intraoral
pressure for some sounds. Nasal air escape and hypernasality are typical of VPD. Hypernasality
is a resonance alteration that affects the emission of vowel sounds, whereas nasal
air escape is a change in speech articulation that hinders the production of high
pressure consonants such as plosives and fricatives[1 ].
Several methods for evaluating the VPS have been designed. The choice of a specific
evaluation method is directly related to the focus of interest of a clinical investigation
and its need for accuracy. The use of 1 auditory-perceptual assessment and at least
1 instrumental assessment is recommended for the analysis of velopharyngeal function[2 ]
[3 ].
Auditory-perceptual assessment is the main method for detecting possible changes in
speech nasality, and provides data on the function of velopharyngeal structures during
speech production. That is, this evaluation method makes it possible to detect specific
symptoms of cleft palate that may or may not be associated with VPD[4 ]
[5 ]
[6 ]
[7 ]. Because auditory-perceptual assessment is easily performed, it is the most commonly
used evaluation method in clinical practice[8 ]
[9 ]. Analysis of the test results has been widely discussed in the literature because
of a lack of uniformity in the protocols used by researchers and institutions, which
makes it difficult to compare study results[2 ].
Videonasoendoscopy shows dynamic, direct, and natural images of the anatomical structures
of the nasal cavity, pharynx, and larynx; this imaging method is thus one of the most
appropriate tools for assessment of the VPS[10 ]. Velopharyngeal closure patterns and the presence of a velopharyngeal gap (i.e.,
a residual opening during maximum contraction of the VPS) can be detected during performance
of the test. Such patterns can also be identified during speech production, including
the characteristics and degree of movement of the soft palate and pharyngeal walls[11 ]
[12 ]
[13 ].
Based on both the literature and clinical practice, it is possible to state that the
anatomy and physiology of the velopharyngeal mechanism are complex. Velopharyngeal
dysfunctions that impair oral communication skills because of hypernasality, nasal
air escape, and other disorders can be detected in individuals with cleft lip and
palate. Therefore, the objective of the present review was to investigate the main
methods used to evaluate the velopharyngeal function in individuals with cleft lip
and palate, and to determine whether there is an association between videonasoendoscopy
results and auditory-perceptual assessments.
Method
A systematic review of the literature is aimed at providing answers to specific questions
and is based on clear and systematic methods in order to identify, select, and critically
evaluate studies that may meet the proposed objective[14 ]
[15 ]. In order to perform the present systematic review of the literature, we searched
studies conducted in different countries addressing the types of assessments used
to describe the velopharyngeal function in individuals with surgically repaired cleft
lip and palate. The following research questions were proposed: What are the main
methods of velopharyngeal function assessment used in individuals with cleft lip and
palate and how are the findings analyzed by the examiner? Is there an association
between videonasoendoscopy results and auditory-perceptual assessments?
We searched the PubMed, Medline, Lilacs, Cochrane, and SciELO databases from October
to November 2012. The same search strategy was used for all databases. Our search
strategy included only manuscripts published between 1990 and 2012. This period was
selected based on the fact that videonasoendoscopy first appeared in the literature
in 1990. First, we selected the keywords to search the databases considering our research
questions. The following keywords were used alone and in combination with the other
terms: “cleft palate,” “velopharyngeal closure,” “velopharyngeal insufficiency,” “velopharyngeal
dysfunction,” “compensatory articulation,” “videonasoendoscopy,” “assessment and hypernasality,”
“velopharyngeal mechanism,” “hypernasality,” and “speech.”
The abstracts and titles of the manuscripts were selected by 2 researchers who worked
independently. A reviewer resolved potential discrepancies of opinion. The full text
of all potentially relevant manuscripts was obtained and analyzed separately by 2
reviewers based on the following inclusion criteria: (1) involved adults or children
with cleft lip and palate; (2) included at least 1 videonasoendoscopy and 1 auditory-perceptual
assessment for screening of VPD; (3) described the methods and criteria used for the
analysis of the velopharyngeal functional assessment results. Studies on cleft lip
and palate focused on audiological findings, classification of different cleft types,
and surgical interventions were excluded. Finally, 2 researchers who specialize in
the area of interest in the present study revised the selection of manuscripts with
the purpose of refining the results.
Results and Discussion
Considering the objective of the present review of the literature, our search of the
previously mentioned scientific databases retrieved 1,300 manuscripts on velopharyngeal
dysfunction in individuals with cleft lip and palate. Of these, 56 studies addressing
velopharyngeal physiology were selected. Among these studies, there were 29 studies
including data about auditory-perceptual assessment, some of which were associated
with other instrumental assessments. We selected 12 studies that found an association
between instrumental assessments (videonasoendoscopy and other tests) and auditory-perceptual
assessment. Of these, 6 studies used videonasoendoscopy and auditory-perceptual assessment
to evaluate velopharyngeal function. We refined our search in accordance with the
objective of the present review and found only 3 studies that included an explanatory
description of the analysis of both types of assessments.
The characteristics of each study included in this review are shown in [Table 1 ]. The 12 studies selected were conducted in 4 different countries, including Brazil.
These studies involved patients with different types of cleft lip and palate, including
submucous cleft. Their age ranged from 3 to 76 years ([Table 1 ]).
Table 1.
Characteristics of the study.
Author
Country
Type of cleft
Age group
Araújo Netto & Cervantes, 2011
Brazil
CLP, CP
4–19 years old
Trindade et al., 2004
Brazil
CLP, SCP
NA
Chanchareonsook et al., 2007
China
CP
12–18 years old
Kao et al., 2008
United States
CP, SCP
7–11 years old
Marsh, 2009
India
CP, CLP
NA
Miguel et al., 2004
Brazil
SCP, SCLP
6–46 years old
Nagarajan et al., 2009
India
CLP, CP
NA
Penido et al., 2007
Brazil
CP
8–34 years old
Qui Chen et al., 2011
United States
SCP, CP
1–34 years old
Camargo et al., 2001
Brazil
NA
6–76 years old
Shprintzen and Marrinan, 2009
United States
NA
NA
Shyammohan et al., 2010
India
NA
NA
Source: The authors
CLP = cleft lip and palate
CP = cleft palate
SCP = submucuous cleft palate
SCLP = submucous cleft lip and palate
NA = not available
Detailed descriptions of both types of assessment and the parameters used for the
analysis of the results of these 12 studies are shown in Table 2. The direct instrumental
assessments used in these studies included videofluoroscopy, magnetic resonance imaging
(MRI), nasopharyngeal fibroscopy, videonasoendoscopy, nasopharyngoscopy, and nasoendoscopy.
Despite the different terms used, the last 4 assessments consisted of the same type
of test performed with the purpose of viewing the velopharyngeal mechanism. The indirect
instrumental assessments mentioned in these studies were nasometry and the PERCI-SARS
system. The methods of clinical evaluation used in most studies were auditory-perceptual
assessments and nasal airflow measurements. Such tests were analyzed according to
the specific protocols of each institution. The analysis parameters for each type
of instrumental assessment and auditory-perceptual assessment differed for each study
([Table 2 ]).
Table 2.
Tools used in the study.
Authors
Direct instrumental assessment
Indirect instrumental assessment
Clinical evaluation
Araújo Netto & Cervantes, 2011
videonasoendoscopy
Not used
Auditory-perceptual assessmentl
Trindade et al., 2004
Not used
Not used
Auditory-perceptual assessment
Chanchareonsook et al., 2007
nasoendoscopy
nasometry
Auditory-perceptual assessment
Kao et al., 2008
nasoendoscopy
Not used
Auditory-perceptual assessment
Marsh, 2009
videonasoendoscopy
Not used
Auditory-perceptual assessment
Miguel et al., 2004
videonasoendoscopy
nasometry/PERCI-SARS
Auditory-perceptual assessment
Nagarajan et al., 2009
Videonasoendoscopy and
nasometry
Auditory-perceptual assessment
videofluoroscopy
Penido et al., 2007
nasopharyngoscopy
Not used
Nasal air emission test
Qui Chen et al., 2011
lateral cephalogram of
Not used
Auditory-perceptual assessment
nasopharyngography and
nasopharyngeal fiberscope
Camargo et al, 2001
nasoendoscopy
Not used
Auditory-perceptual assessment
focused on nasal air emission
Shprintzen e Marrinan, 2009
Nasopharyngoscopy and MRI
nasometry
Not used
Shyammohan et al, 2010
Not used
Not used
Auditory-perceptual assessment
Source: The authors.
Our decision to conduct a systematic review with the previously mentioned objective
was prompted by a problem faced by health professionals who provide clinical care
to patients with cleft lip and palate, that is, the impact of VPD on these patients'
verbal communication skills. Discrepancies in findings relating to speech nasality
and the degree of velopharyngeal closure are common in clinical practice. Clinical
reports of verbal communication based on auditory-perceptual assessments reveal situations
where the examiners detect severe hypernasality and, conversely, videonasoendoscopy
shows a small velopharyngeal gap. Inversely proportional situations also occur when
a large gap has little impact on nasality. Thus, the association between the clinical
and instrumental evaluations is very important for achieving a clinical conclusion
as to the real condition of the velopharyngeal mechanism. Even though we are aware
that the pathophysiology of the velopharyngeal sphincter is complex and involves a
variety of biases produced by the patient or the examiner, we searched for studies
addressing this issue (i.e., the association between the size of the gap and the impact
on nasality) in a straightforward manner. Therefore, the 3 studies selected are discussed
further in an attempt to determine significant aspects related to the velopharyngeal
mechanism and nasality. It is noteworthy that the specific association of interest
in the present review was not explained by any of these studies, revealing the scarcity
of scientific literature on the topic ([Figure 1 ]).
Figure 1. Logistics associated with the systematic review.
While investigating this topic, Marsh (2009) addressed the velopharyngeal closure
and provided a description of videonasoendoscopy and auditory-perceptual assessment
in a study involving patients with cleft palate. Marsh suggested a classification
of the residual gap in the VPS closure using different closure patterns during speech
production, and considers investigation of the VPS closure pattern and analysis of
lateral pharyngeal wall movement essential for establishing the diagnosis of VPD.
Although there is no direct association between findings of nasality, audible nasal
air emission, and the classification proposed, analysis of these findings does facilitate
clinical surgical intervention.
Qi Chen et al. (2011) used analysis of the lateral pharyngeal wall movement as a diagnostic
criterion for VPS, considering that most patients without nasality and audible nasal
air emission have sagittal closure. This study included 276 individuals aged 6 to
12 years. Despite considering factors such as surgical age and technique, Qi Chen
et al. and Marsh both highlight the role played by lateral wall movement in satisfactory
functioning of the VPS, and the consequences and impact on nasality.
With the purpose of demonstrating an association between audible nasal air emission
and VPS closure pattern shown by videonasoendoscopy, Penido et al. (2007) found a
valid association between these aspects by means of comparison. These authors described
the reliability of the correlation between the Glatzel mirror test using nasal air
escape and VPS closure pattern in 21 individuals with cleft lip and palate whose mean
age was 17 years. Based on videonasoendoscopy, the size of the gap was categorized
as small, medium, or large. This study demonstrated that the nasal air emission test
is useful for evaluating the function of the velopharyngeal mechanism, and for establishing
a direct relationship between the size of the gap and the area of condensation on
the mirror. It is worth noting that these authors found divergent behaviors of the
velopharyngeal mechanism considering the nasal air escape expected in an individual
from this sample.
Conclusions
In the present systematic review of the literature we identified different evaluation
methods used for determining velopharyngeal function. However, we found few studies
that showed both the detailed criteria chosen to analyze the results of the assessments
and the association between videonasoendoscopy results and auditory-perceptual assessments.
Only 1 study demonstrated an association between findings of VPD assessed using videonasoendoscopy
and the severity of audible nasal air escape evaluated by auditory-perceptual assessment.
