Craniofacial Anomalies, Cleft Lip/Palate, and Resonance Disorders
Velopharyngeal dysfunction (VPD) may result from structural defects (e.g., cleft palate, short soft palate, deep pharynx, cervical spine anomalies, etc.), neurological/physiological disorders (e.g., dysarthria, apraxia), and development of atypical articulatory placements and error patterns (e.g., velopharyngeal mislearning). Cleft palate is one of the most well-known causes of VPD. Clefts are categorized based on the severity, presentation, and combination of cleft lip and/or palate. Clefts can be unilateral or bilateral and complete or incomplete. Submucous cleft palate is a type of cleft in which the mucous membrane along the roof of the mouth develops over a cleft of the bony hard palate. A variation of levator veli palatini muscle bundle separation or abnormal muscle insertion (i.e., separation in the midline) often co-exists.
Children with cleft lip and palate do not represent a homogenous population, and the signs and symptoms associated with clefting depend on a variety of factors. Common issues that children with a history of cleft palate can encounter include problems related to:
- Dental and occlusal deviations
- Hearing and middle ear function
- Psychosocial development
- Speech sound acquisition and language development
Brief Definitions of Key Terminology
- Hypernasality: excessive nasal resonance or too much nasality during speech
- Hyponasality/denasality: too little nasal resonance during speech
- Cul-de-sac resonance: speech sounds muffled due to obstruction and inability for air to resonate appropriately in the oral or nasal cavities
- Mixed resonance: inconsistent resonance and/or combination of hypernasality and hyponasality during speech
- Nasal air emission: audible or inaudible release of air through the nose during production of high pressure consonants—the stops, fricatives, and affricates
- Compensatory articulation errors: learned articulation errors that require speech therapy to teach correct placement. Common types of compensatory articulation errors are glottal stops, mid-dorsum palatal stops, pharyngeal fricatives, and nasal fricatives.
The goal of the speech evaluation of a child with cleft palate or suspected velopharyngeal dysfunction is to answer two simple questions: What is the child doing now? What is the child capable of doing? The answers to these questions will help determine whether and/or when a child would benefit from speech therapy and if further physical management is warranted. The preferred model for evaluation is assessment by a cleft palate/craniofacial team that includes a speech-language pathologist, rather than a medical intervention model where the patient is seen by an individual otolaryngologist, ENT, or plastic surgeon. Evaluation includes:
- Thorough medical and surgical history
- Perceptual speech evaluation involving many components:
- Resonance and airflow/pressure evaluation is used to determine if the child presents with a resonance disorder, nasal air emission, or both. Resonance is assessed using voiced (resonating) sounds, including vowels, nasal consonants, and vocalic consonants. Airflow and pressure is assessed using high pressure consonants, including stops, fricatives, and affricates.
- Articulation evaluation should include a conversational speech sample and structured informal speech tasks (e.g., repetition of CV utterances, words, and sentences and elicited naming activities). The articulation assessment is used to determine if the child's speech errors are obligatory or compensatory. Obligatory errors are caused by structural or neurogenic problems, such as fistulas or velopharyngeal insufficiency. These errors will require physical management to correct. Compensatory articulation errors are learned articulation errors that some children with cleft palate or velopharyngeal dysfunction develop in their early speech learning due to an inability to generate adequate intra-oral air pressure for typical production of pressure consonants. Compensatory errors may be referred to as "cleft type" speech errors. They can be difficult to identify, and accurate perceptual identification takes practice. Velopharyngeal mislearning includes these compensatory errors as well as (learned) phoneme-specific nasal air emission in which nasal air emission is noted only on particular speech sounds, especially /s/ and the other sibilant fricatives and sometimes affricates. All of these learned errors are corrected through speech therapy only.
- Resonance and voice are two distinct speech parameters with different anatomical and physiological components. Therefore, dysphonia, especially voice quality deviation, should be noted separately, as this can mask the presence and degree of perceived hypernasality.
- Oral mechanism examination is completed to assess oral cavity structures and examine dentition, tonsils, and occlusal status. In patients who present with hypernasal speech without a history of cleft palate, look for three classic signs of submucous cleft palate: bifid uvula, midline pale/bluish white zone in the midline of the palate, and palpable notch in the posterior border of the hard palate.
- Standardized tests for speech and language assessment are formal language and speech sound assessment tools, which can be valuable in determining performance in relation to normative data.
- Instrumental evaluation is used to further examine and explain or refute the conclusions drawn from the perceptual analysis. This can include a number of methods available through CLP/craniofacial teams, such as pressure-flow/aerodynamic studies, videofluoroscopy, and nasopharyngoscopy. Nasometry is another option.
Partnership between the community or school-based SLP, cleft/craniofacial team SLP, and parents/caregivers typifies best practice for intervention. Making sure a child is referred and being followed by a cleft palate-craniofacial team is a critical step in the process of developing collaboration for treatment planning and specific therapy activities. A listing of cleft palate-craniofacial teams can be found through the American Cleft Palate Craniofacial Association (ACPA).
Speech therapy cannot correct hyper- or hyponasality, and therapy instead focuses on treating compensatory (learned) errors by targeting correct oral placement of the articulators and establishing oral airflow direction and pressure build-up. General therapy goals for children with cleft palate speech sound disorders include:
- Establish correct oral articulatory placement and/or airflow direction and pressure build up at the target place, using behavioral, articulation (motor-phonetic) therapy.
- Maximize the intra-oral air pressure build up during speech sound production.
- Teach new motor speech patterns to replace compensatory maladaptive articulation errors.
For the clinician treating individuals with resonance disorders, oral-motor exercises, specifically non-speech tasks (e.g., blowing, whistling, sucking, horn therapy, palatal massage, etc.) are typically not effective in treating any speech errors.