Instrumental Evaluation

How can instrumentation and imaging help with speech disorders?

  • They improve our understanding by direct measurement and visualization of the vocal tract during function. 
  • The mechanisms of velopharyngeal closure and larynx are not visible from oral exam and are only visible by endoscopy, radiography or fluoroscopy. 
  • The ears may detect gross disturbance, but ears are not reliable to discern subtleties of speech. 
  • Instrumentation can define the subtleties of speech and measure several speech processes simultaneously. 
  • Instrumentation provides quantifiable documentation of change following speech therapy or physical management. 

How does computerized instrumentation assist the evaluation?

  • Assessment with computerized instruments is objective and more accurate than perceptual judgments alone. 
  • Speech performance can be compared to standardized peer group norms. 
  • Pre and postmeasures make outcomes easier to evaluate. 
  • Computers can measure several speech qualities simultaneously. 
  • Voice and resonance measures can be taken at the same time. 
  • Objective measures can be taken during diagnostic or trial therapy to assess the effectiveness of a therapeutic technique.

What instruments are used to image the vocal tract?

  • Flexible endoscopy
  • Videofluoroscopy 
  • Cephalometric radiography

How does imaging assist the evaluation?

  • Allows us to view the structure and the function of the speech mechanism that is not visible during an oral exam. 
  • Information from lateral fluoroscopy/radiography and endoscopy has improved the outcome of surgery for hypernasality. 

Surgical and Prosthetic Management of Velopharyngeal Incompetence (VPI)

When is physical management of velopharyngeal incompetence necessary?

  • Speech is unintelligible due to VPI. 
  • Articulation is imprecise due to loss of oral pressure. 
  • Misarticulations such as glottal stops cannot be corrected because of nasal air pressure loss. 
  • Speech is distorted from hypernasal distortions. 

What are the prosthetic management procedures?

  • The common prosthetic procedures are the palatal lift and the palatal obturator.
  • A palatal lift is appropriate when the VPI is caused by poor movement of the velum. The anterior, retaining portion clasps to the teeth and a posterior tailpiece pushes the soft palate up into position to obturate the nasopharynx. 
  • A palatal obturator is appropriate when the VPI is caused by a deficiency in the length of the soft palate to close the velopharyngeal port. That is, the velum may move, but may not be long enough, or the nasopharynx may be too deep to achieve closure. 

When is prosthetic management appropriate?

Prosthetic procedures are most commonly used in neurogenic VPI.

Prosthetic management is best suited to individuals with: 

  • Healthy dentition, in good repair
  • Minimal or controlled gag response
  • Good motion of the oral articulators
  • Good oral pressure when the pressure consonants are tested with nasal occlusion
  • Good manual dexterity or supervision for inserting and removing the prosthesis 

What kinds of surgical management are used to correct VPI?

The two most common types of surgical management (pharyngoplasties) are: (1) the pharyngeal flap and (2) the sphincter pharyngoplasty. These procedures make the nasopharynx smaller, but in different ways.

  • A pharyngeal flap raises a vertical flap of tissue from the posterior pharyngeal wall. The flap is pulled across the nasopharynx and sutured into the velum. This leaves two openings on either side of the flap that are closed during speech by the inward movement of the lateral pharyngeal walls. 
  • A sphincter pharyngoplasty raises vertical flaps of tissue from each lateral pharyngeal wall, rotates them inward to a horizontal position and inserts them into the posterior pharyngeal wall. This leaves a single (smaller) opening that is closed by the elevation of the velum.