Children with craniofacial anomalies often demonstrate disorders of speech and/or resonance. Anomalies that affect speech and resonance are most commonly caused by clefts of the primary palate and secondary palate. This article discusses how speech-language pathologists evaluate the effects of dental and occlusal anomalies on speech production and the effects of velopharyngeal insufficiency on speech sound production and resonance. How to estimate the size of a velopharyngeal opening based on speech characteristics is illustrated. Nasometry, nasopharyngoscopy, and low-tech tools are discussed as adjunct methods to aid in the evaluation, treatment planning, and measurement of outcomes.
Key points
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Speech and resonance disorders are common in patients with craniofacial anomalies, particularly those with clefts.
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Dental and occlusal anomalies can affect lingual-alveolar and bilabial sounds, whereas velopharyngeal insufficiency can cause hypernasality and/or nasal emission on pressure-sensitive sounds.
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In addition to an assessment of speech sound placement, manner of production, and voicing, the speech evaluation should also include an assessment of the presence of obligatory distortions or compensatory errors when there are oropharyngeal anomalies. The presence, audibility, and consistency of nasal emission on speech sounds are also important to note.
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The speech evaluation should always include an assessment of the type of resonance (normal, hypernasal, hyponasal, or cul-de-sac resonance). Severity ratings typically are not useful in determining appropriate management.
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Instrumental measures (whether high-tech or low-tech) can augment the perceptual evaluation and provide useful information for surgical management and measurement of outcomes.
Video content accompanies this article at http://www.facialplastic.theclinics.com .
Introduction
Children with craniofacial anomalies often demonstrate disorders of speech and/or resonance due to structural anomalies of the jaws, oral cavity, and velopharyngeal (VP) valve. These anomalies are most commonly caused by clefts of the primary palate and secondary palate.
Clefts of the primary palate (particularly complete clefts that go through the alveolus) often result in dental anomalies and/or malocclusion. Dental anomalies, such as misplaced or supernumerary teeth, can interfere with tongue tip movement, and affect lingual and even bilabial placement during speech. Because the tongue tip needs to be positioned under the alveolar ridge and the lips need to come together easily for production of many speech sounds, malocclusion of the jaws is an even bigger problem for speech. With a class III maloclussion (and often with just an anterior crossbite), the tongue tip is positioned anterior to the alveolar ridge, which can affect the production of lingual-alveolar sounds (t, d, n, l, s, z) and even bilabial sounds (p, b, m). With a severe class II maloclussion secondary to micrognathia, the tongue tip may be positioned behind the alveolar ridge and under the palatal vault, making lingual-alveolar and bilabials sounds virtually impossible to produce normally.
Clefts of the secondary palate often result in VP insufficiency (VPI), which is defined as abnormal structure of the VP valve. It is estimated that, despite palatoplasty, 20% to 30% of children with repaired cleft palate will demonstrate some degree of VPI, resulting in abnormal speech. Depending on the size of the opening, VPI can cause hypernasality (an abnormality of resonance) and/or nasal air emission (an abnormality of airflow).
Introduction
Children with craniofacial anomalies often demonstrate disorders of speech and/or resonance due to structural anomalies of the jaws, oral cavity, and velopharyngeal (VP) valve. These anomalies are most commonly caused by clefts of the primary palate and secondary palate.
Clefts of the primary palate (particularly complete clefts that go through the alveolus) often result in dental anomalies and/or malocclusion. Dental anomalies, such as misplaced or supernumerary teeth, can interfere with tongue tip movement, and affect lingual and even bilabial placement during speech. Because the tongue tip needs to be positioned under the alveolar ridge and the lips need to come together easily for production of many speech sounds, malocclusion of the jaws is an even bigger problem for speech. With a class III maloclussion (and often with just an anterior crossbite), the tongue tip is positioned anterior to the alveolar ridge, which can affect the production of lingual-alveolar sounds (t, d, n, l, s, z) and even bilabial sounds (p, b, m). With a severe class II maloclussion secondary to micrognathia, the tongue tip may be positioned behind the alveolar ridge and under the palatal vault, making lingual-alveolar and bilabials sounds virtually impossible to produce normally.
Clefts of the secondary palate often result in VP insufficiency (VPI), which is defined as abnormal structure of the VP valve. It is estimated that, despite palatoplasty, 20% to 30% of children with repaired cleft palate will demonstrate some degree of VPI, resulting in abnormal speech. Depending on the size of the opening, VPI can cause hypernasality (an abnormality of resonance) and/or nasal air emission (an abnormality of airflow).
Perceptual assessment of speech and resonance
Children with clefts and other craniofacial anomalies should receive yearly speech evaluations by a speech-language pathologist (SLP) (preferably one associated with a craniofacial team) during the preschool years until speech is age-appropriate. These children should continue to receive at least screening evaluations through puberty.
What to Evaluate
As part of a typical examination of a child with craniofacial anomalies, the SLP will assess speech sound production, the presence of nasal emission on pressure-sensitive phonemes (speech sounds), and resonance. The examiner will also attempt to determine the cause of abnormalities in speech and/or resonance that are found.
Speech sound production
After listening to an inventory of all speech sounds in the child’s language, the SLP will note errors of placement, errors of manner (eg, nasal, plosive, fricative, affricate), and errors of voicing (eg, use of voiced for voiceless phonemes or vice versa). The examiner will determine if multiple errors are related phonologically, which is important for therapeutic intervention. The examiner will also determine if the errors are consistent (eg, the error occurs in all conditions and all word positions) or are not consistent. Developmental errors (those that are normal for the child’s age) are also noted. Finally, when there are structural anomalies, including dental anomalies, occlusal anomalies, and VPI, the examiner will determine if there are obligatory distortions and/or compensatory errors.
Obligatory distortions occur when the child’s articulation placement is normal but the abnormal structure causes distortion of the sounds. These distortions will self-correct with correction of the structure and, therefore, are not appropriate for speech therapy. Compensatory errors occur with the child alters his or her articulation to compensate for the structural abnormality. Common compensatory errors for anterior crowding of the tongue tip or for class III maloclussion are palatal-dorsal substitutions. Common compensatory errors for VPI include glottal stops and pharyngeal fricatives. These errors require speech therapy, ideally after the structure is corrected or at least improved.
Nasal emission
Nasal emission is a release of air flow through the nasal cavity during the production of oral sounds. Nasal emission is most audible on voiceless plosives (p, t, k), voiceless fricatives (f, s, sh), and the voiceless affricate (ch). Therefore, these sounds are typically used for assessment. The examiner will determine if there is audible nasal emission, the loud and distracting nasal rustle (AKA nasal turbulence), or if the nasal emission is inaudible. Box 1 describes the diagnostic characteristics of nasal emission.
Nasal emission affects oral airflow and the ability to build up air pressure during speech. Nasal emission:
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Is characterized by abnormal escape of the air stream through the nasal cavity during production of pressure-sensitive consonants (plosives, fricatives, and affricates).
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Is typically caused by VPI but can also be caused by an anterior oronasal fistula or even by abnormal articulation placement in the pharynx.
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Affects voiceless pressure-sensitive phonemes the most (ie, p, t, k, f, s, sh, ch).
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May be audible or inaudible. If inaudible (due to a large VP opening), it will also cause consonants to be very weak in intensity and pressure, short utterance length (due to the need to take more breaths during speech), and may cause a nasal grimace during speech.
Inaudible nasal emission occurs with a very large VP opening where the airflow travels through the valve with relatively low impedance to the flow. The sound of this nasal emission is very low in volume and is masked by the hypernasality. Inaudible nasal emission will significantly reduce airflow in the oral cavity causing certain other characteristics, including weak or omitted consonants. In addition, the patient will take frequent breaths while speaking to replace the airflow that has leaked through the valve. A nasal grimace (contraction near the nasal bridge and/or around the nostrils) may also occur as an overflow muscle reaction to excessive effort in achieving VP closure. Finally, with a large VP opening, the nasal emission will typically be accompanied by hypernasality.
When the VP opening is very small, there is more impedance to the airflow, resulting in increased audibility of the airflow as it goes through the opening. In addition, the air passes with increased pressure so that as it is released it causes bubbling of secretions on the nasal surface of the VP valve. The sound associated with bubbling, a nasal rustle (nasal turbulence) is very audible and distracting. [CR] demonstrates the sound of a nasal rustle. Because a nasal rustle is due to a small opening, it does not occur with inadequate intraoral air pressure needed for consonant production.
In addition to the quality of nasal emission, the examiner will judge its consistency. If nasal emission occurs inconsistently but on all pressure-sensitive phonemes, the cause is typically VPI. On the other hand, if it occurs consistently but only on specific phonemes, it is considered phoneme-specific nasal emission (PSNE). PSNE is caused by the use of pharyngeal or nasal fricative substitutions for some or all of the sibilant sounds (s, z, sh, zh, ch, j) and is only due to abnormal articulatory placement. Because this is a functional disorder, this can be corrected with speech therapy, rather than surgery.
Resonance
Determining the type of resonance (normal, hypernasal, hyponasal, cul-de-sac, or mixed) is very important because it gives clues as to the cause of the resonance disorder and the type of management required for correction. Box 2 describes the diagnostic characteristics of these resonance disorders. [CR] shows an example of hypernasality and [CR] is an example of hyponasality. Severity ratings of abnormal resonance are now being used for comparison of outcomes, although adequate interjudge reliability requires training. From a clinical standpoint, if the parents want the abnormal resonance due to VPI or obstruction corrected, the severity rating is not relevant because it does not determine the type of physical management (usually surgery) that is required. Hypernasality due to VPI, which is a structural anomaly, will require surgical intervention, whereas hyponasality may benefit from pharmacologic management (eg, nasal sprays) or surgical treatment to decrease nasopharyngeal obstruction. Structural anomalies always require surgical management for correction. Speech therapy is not appropriate unless the abnormal resonance is phoneme-specific and due to misarticulation.
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