Understanding Cleft Lip and Palate:

• Cleft Lip:
  • A separation or opening in the upper lip.
  • Occurs when the facial structures that form the lip do not close completely during fetal development.
  • Can be unilateral (one side) or bilateral (both sides).
• Cleft Palate:
  • A separation or opening in the roof of the mouth (palate).
  • Occurs when the palatal structures that form the roof of the mouth do not close completely during fetal development.
  • Can involve the hard palate (bony front portion) and/or the soft palate (muscular back portion).

Effects on Speech Production:

1. Resonation (Hypernasality):
   • A cleft palate creates an abnormal opening between the oral and nasal cavities.
   • This opening allows air to escape through the nose during speech, resulting in hypernasality.
   • Sounds that should be produced orally (like vowels and most consonants) become nasalized.
   • The velopharyngeal mechanism (the soft palate and surrounding muscles) is responsible for closing off the nasal cavity during speech. A cleft palate disrupts this mechanism.
   • The feather test at the nostril is a simple way of showing the nasal air emmisions that occur during speech.
2. Articulation:
   • Cleft Lip:
     • Can affect the production of bilabial sounds (sounds made by bringing the lips together), such as /p/, /b/, and /m/.
     • Difficulty creating a proper lip seal can result in distorted or imprecise articulation of these sounds.
   • Cleft Palate:
     • Can affect the production of sounds that require intraoral air pressure, such as plosives (/p/, /b/, /t/, /d/, /k/, /g/) and fricatives (/s/, /z/, /f/, /v/).
     • Air leakage through the cleft makes it difficult to build up the necessary pressure.
     • Compensatory articulation patterns may develop, such as glottal stops (using the vocal folds to produce a stop consonant) or pharyngeal fricatives (using the back of the throat to produce a fricative sound).
     • Dental abnormalities are common with clefts, and these abnormalities can also greatly effect articulation.
3. Compensatory Articulation:
   • Due to the physical limitations, individuals with clefts often develop compensatory articulation patterns. These are ways of producing sounds that are not typical, but allow the person to be understood.
   • These patterns can become habitual, and require speech therapy to correct.

Causes and Treatment:

• Causes:
  • Cleft lip and palate are congenital conditions, meaning they are present at birth.
  • They result from a combination of genetic and environmental factors.
  • Genetic factors can include inherited predispositions.
  • Environmental factors can include exposure to certain medications, alcohol, or smoking during pregnancy.
• Treatment:
  • Treatment typically involves a multidisciplinary team, including:
    • Surgeons (for lip and palate repair).
    • Speech-language pathologists (for speech therapy).
    • Audiologists (for hearing evaluations).
    • Dentists and orthodontists (for dental and orthodontic care).
  • Surgical repair of the lip and palate is usually performed in stages.
  • Speech therapy is essential to address articulation and resonation issues.
  • Prosthetic devices can also be used to help with closing the opening in the palate.

Applying Anatomy and Physiology:

• Understanding the anatomy of the oral and nasal cavities, the velopharyngeal mechanism, and the articulators (lips, tongue, teeth) is crucial for diagnosing and treating speech disorders associated with cleft lip and palate.
• Knowledge of the physiology of speech production, including resonation and articulation, is essential for developing effective treatment plans.
• Speech-language pathologists use their knowledge of anatomy and physiology to assess the specific speech deficits of individuals with cleft lip and palate and to design targeted interventions.