Dental and/or Occlusal Abnormalities

Children with a cleft of the primary palate that extends into the alveolar ridge will often have dental and/or occlusal abnormalities. Dental anomalies, particularly supernumerary or displaced teeth, can interfere with tongue tip movement during speech production. Malocclusion is an even greater concern for speech. This is because it can affect the normal relationship between the tongue tip and the alveolar ridge ( Fig. 11.1 ).

Whenever there are structural abnormalities within the vocal tract, this can cause either obligatory distortions or compensatory errors. Obligatory speech distortions occur when the articulation placement is correct, but an abnormality of the structure results in a distortion of speech.1,2 Obligatory distortions are common with dental/occlusal anomalies, and often cause distortion of sibilant sounds (s, z, sh, ch, j). In contrast, compensatory speech errors are the result of incorrect articulatory placement in response to abnormal structure.1,2 An example of a compensatory error is when the production of the sounds “t” or “d” is altered from the normal placement (tongue tip to alveolar ridge) to an abnormal placement (dorsum of the tongue to the palate). This commonly occurs in response to an anterior crossbite.

Hearing Loss

Children with cleft palate are at increased risk for both conductive and sensorineural hearing loss.3–5 The cleft palate can cause abnormalities of the tensor veli palatini muscles, which are responsible for eustachian tube function. Eustachian tube dysfunction can result in chronic middle ear effusion and fluctuating conductive hearing loss. Fluctuating conductive hearing loss can cause a delay in speech and/or language development, but this delay is usually resolved quickly with treatment. Prophylactic insertion of pressure equalizer tubes is therefore often done in patients with cleft palate.

Children with cleft palate and associated craniofacial syndromes (i.e., Treacher Collins syndrome) are also at risk for anomalies of the external, middle, and inner ear. As a result, they may demonstrate a more significant conductive hearing loss and/or a sensorineural hearing loss. These types of hearing loss have a greater and more long-lasting effect on speech and language development.

Upper Airway Obstruction

Children with cleft lip and palate are at risk for upper airway obstruction for many reasons.6 Those born with Pierre Robin sequence, including micrognathia and glossoptosis, tend to have a very small oropharynx, which primarily affects respiration, but can also affect resonance. Children with unilateral cleft lip and palate often have a deviated septum. For older children and adults, the size of the nasal cavity and the depth of the pharynx may be affected by maxillary retrusion. Regardless of the cause, upper airway obstruction can cause hyponasality or cul-de-sac resonance.

Velopharyngeal Insufficiency

The primary purpose of a palate repair is to achieve normal velopharyngeal function for speech. As such, there is firm closure of the velum against the pharyngeal wall during the production of all oral sounds ( Fig. 11.2 ). The greatest concern for children with cleft palate is the risk for VPI.7 Despite undergoing palatoplasty surgery, 20 to 30% of children with repaired cleft palate will demonstrate some degree of velopharyngeal dysfunction (VPD), resulting in abnormal speech.

A word about terminology may be appropriate here. The term velopharyngeal dysfunction (VPD) is a general term that refers to the inability of the velum to completely close the nasal cavity from the oral cavity during the production of oral (nonnasal) sounds. Other terms are used to indicate a general causality.1,8,9 The term velopharyngeal insufficiency (VPI) is typically used to describe an anatomic or structural defect that prevents adequate velopharyngeal closure. VPI is the most common type of VPD because it includes the causes of cleft palate and submucous cleft palate ( Fig. 11.3 ). In contrast, the term velopharyngeal incompetence (also abbreviated VPI), is used to refer to a neurophysiological disorder that causes poor movement of the velopharyngeal structures ( Fig. 11.4 ). Both forms of VPI require surgical or prosthetic management. Finally, velopharyngeal mislearning is a term to describe an articulation placement disorder that includes the substitution of nasal or pharyngeal sounds for oral sounds, resulting in an open velopharyngeal valve during the production. Children with VPI often develop compensatory productions (a form of velopharyngeal mislearning), which require speech therapy after physical correction of the abnormal structure. These types of VPD are further outlined in Table 11.1 . Note that when the abbreviation VPI is used, it refers to velopharyngeal insufficiency and incompetence (both of which require physical management) in contrast to velopharyngeal mislearning (which requires speech therapy only).

Patient History

Prior to the perceptual evaluation of resonance and velopharyngeal function, the examiner should obtain a thorough history through chart review, a pre-evaluation questionnaire (if possible), and a family (or patient) interview.10,11 In particular, it is important to determine information in the following general categories:

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  Current concerns of the parents and other family members

  
  
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  Diagnoses

  
  
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  Surgical history

  
  
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  Feeding/swallowing history

  
  
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  Motor developmental history

  
  
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  Speech/language/learning developmental history

  
  
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  Airway history

  
  
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  Previous or current speech therapy

Speech Samples for Assessment

Choosing appropriate speech samples for the assessment is very important, and key to obtaining information needed for a definitive diagnosis. Separation of the oral speech samples from the nasal speech samples during testing allows the examiner to isolate the type of abnormal resonance, when it occurs. For children, the speech samples should also be developmentally appropriate in areas of content, speech sound production, and syntax. Children are generally ready for this level of testing around the age of 3 years old.

Articulation

As part of a standard articulation test, the examiner typically records all misarticulations and determines which are placement errors, errors due to oral-motor dysfunction, or developmental errors. When there are structural abnormalities (e.g., VPI or malocclusion), the examiner must also determine if there are compensatory errors or obligatory distortions.

As noted previously, compensatory articulation productions are often developed when there are dental/occlusal anomalies or inadequate intraoral air pressure for production of consonant sounds due to VPI.23 For example, when there is interference with tongue tip movement from the anterior teeth, the examiner should look for the dorsum of the tongue articulating against the palate. When there is VPI, the examiner should determine whether sounds are produced in the pharynx where there is a greater amount of air pressure.

Common compensatory productions for VPI include glottal stops, pharyngeal plosives, pharyngeal fricatives, and posterior nasal fricatives. These productions can often be coarticulated with the correct oral sound. Therefore, the examiner must determine if there is a coarticulation with each sound. For example, the examiner can determine if a glottal stop is being coarticulated with the oral sound by looking for a contraction at the neck, or even feeling the neck during sound production. Pharyngeal fricatives and nasal fricatives can be difficult to distinguish for an inexperienced listener. However, the truth is that it doesn′t matter because the treatment is the same.

Obligatory distortions secondary to VPI include hypernasality and nasal emission. In addition, some oral phonemes will sound like their nasal cognates (i.e., “m” for “b,” “n” for “d,” “ng” for “g”). It should be remembered that obligatory distortions (including hypernasality and nasal emission) cannot be corrected with speech therapy.23

Once all articulation errors are recorded, the examiner should test stimulability. In general, if the individual can produce the correct speech phoneme without nasality after instructions on changing placement, this is a good prognostic indicator for correction with therapy.7 On the other hand, if nasality occurs with normal articulation placement, this strongly suggests VPI, which requires surgical correction. If the patient has compensatory errors as a result of VPI, it is usually best to correct the structural defect first, and then initiate therapy to correct the faulty placement.