About cleft palate and VPI

What is Cleft Palate Lip / Palate?

Cleft lip / palate is a structural anomaly, where-in the normal lip and palatal structures do not fuse in the midline during embryological development.

Estimates of incidence vary – approximately 1 in 700 live births.

The Children’s Hospital Westmead book Cleft Lip and Palate, a Parents’ Guide is a good introduction to cleft palate.

This picture shows an unrepaired secondary cleft (cleft palate) in a 6 month old child who has had repair of a bilateral lip cleft.

This image is a still taken from an iCAT scan. A full iCAT scan would provide a three dimensional image of the child’s skeletal and dental structures. This can assist greatly in dental and surgical management of the patient. The patient below has mixed adult and deciduous dentition

Currently in NSW, antenatal ultrasound scanning is routinely offered to women around 20 weeks of gestation. In-utero diagnosis from ultrasound scan is able to identify surface defects such as a cleft of the lip, but is not able to visualise internal structures such as the hard and soft palate.

What is VPI?

The diagram below shows a simplified representation of normal velopharyngeal function during speech – the velopharyngeal port directs sound energy into the mouth or nose.

Soft palate at rest or during production of nasal consonant	Soft palate during production of oral consonant or vowel

Pictures reproduced with kind permission of Dr Anne Harding-Bell

An animated lateral view of velopharyngeal closure is available in the following links:

• MRI movie (60 sequential frames) obtained during articulation of /pa/ by non-CLP subject
• MRI movie (60 sequential frames) obtained during articulation of /pa/ by CLP subject

Reference
Hideo Shinagawa, Takashi Ono, Ei-Ichi Honda, Shinobu Masaki, Yasuhiro Shimada, Ichiro Fujimoto, Takehito Sasaki, Atsushi Iriki, Kimie Ohyama (2005) Dynamic analysis of articulatory movement using magnetic resonance imaging movies: Methods and implications in cleft lip and palate. The Cleft Palate-Craniofacial Journal: Vol. 42, No. 3, pp. 225-230. 

See also Kummer (2008) DVD clip 16-01 for normal velopharyngeal closure and clip 16-04 for velopharyngeal inadequacy.

Note the Kummer (2008) DVD, Clip 12-2 shows an example of a speech pathologist explaining velopharyngeal function and dysfunction to a parent using a cross-section diagram.

Contributors to velopharyngeal closure are:

• Elevation of soft palate
• Anterior movement of posterior pharyngeal wall
• Inward movement of lateral pharyngeal walls

Note that different individuals have different patterns of velopharyngeal closure, with different amounts of contribution from the structures above. This is important because the size and shape of a velopharyngeal gap will influence the choice of surgical repair for VPI.

Note also:

• There seems to be a separate neurological mechanism for velopharyngeal closure during non-speech activities (eg swallowing) vs closure for speech.
• Closure patterns differ physiologically for different pneumatic activities (eg blowing vs speech).
• Velopharyngeal closure varies with different phonemes, with the greatest velopharyngeal closure employed for high pressure consonants (plosives, fricatives, affricates).

For a detailed discussion of the anatomy and physiology of the velopharyngeal structures, refer to:

Kummer, A.W. (2008) Cleft Palate and Craniofacial Anomalies: Effects on Speech and Resonance (2nd ed.). Thompson Delmar Learning, Chapter 7.

See also:

Kummer, A. W., Lee, L. (1996). Evaluation and treatment of resonance disorders. Language, Speech and Hearing Services in Schools, 27, 271-281.
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VPI - terminology

VPI stands for velopharyngeal inadequacy.

Use of terminology varies in different texts. Kummer, 2008 (p 179) and Peterson-Falzone, Trost-Cardamone, Karnell & Hardin- Jones., 2005 (p18) use the following terminology which more specifically describes the cause of the velopharyngeal problem. The chart below is kindly reproduced with permission from Elsevier. It can also be downloaded from the CD which accompanies their text book.

Velopharyngeal insufficiency (VPI) refers to insufficient velopharyngeal closure due to an anatomical or structural defect.

Velopharyngeal incompetence (VPI) refers to poor velopharyngeal function resulting from a neuromotor or physiological disorder.

The term velopharyngeal mislearning is used when velopharyngeal closure is physically possible, but an aberrant phonological pattern has been learnt.

Kummer (2008)  states that  velopharyngeal dysfunction is likely to be present in 20-30% of individuals with a history of cleft palate.

Further reading

• Kummer, A.W. (2008) Cleft Palate and Craniofacial Anomalies: Effects on Speech and Resonance (2nd ed.). New York: Thompson Delmar Learning, Chapter 13.
• Peterson-Falzone, S., Trost-Cardamone, J.E., Karnell, M. & Hardin-Jones, M. (2005). The Clinician’s Guide to Treating Cleft Palate Speech. NY: Mosby, Chapter 6.