Velum Muscles and VPP Closure Methods

Velum Muscles and VPP Closure Methods

Introduction

• Velum:
  • Also known as the soft palate.
  • Crucial for managing airflow between the oral and nasal cavities during speech.
  • Contains several muscles responsible for its complex movement.

Learning Objectives

By the end of this lesson, you should be able to:

• Identify and describe the different muscles of the velum.
• Identify and describe different methods of Velopharyngeal Port (VPP) closure.

Muscles of the Velum

• The velum comprises various muscles that facilitate its movement and function in speech production.

1. Levator Veli Palatini

• Origin: Petrous part of temporal bone and cartilage of the Eustachian tube.
• Insertion: Palatine aponeurosis of the soft palate.
• Function: Elevates the soft palate to close off the nasopharynx.
• Significance: This is the most important muscle for velum raising.

2. Tensor Veli Palatini

• Origin: Sphenoid bone near the base of the skull and the Eustachian tube.
• Insertion: Palatine aponeurosis.
• Function: Tenses the soft palate and opens the Eustachian tube.

3. Palatoglossus

• Origin: Palatine aponeurosis of the soft palate.
• Insertion: Lateral sides of the tongue.
• Function: Draws the soft palate towards the tongue and narrows the oropharyngeal isthmus.
• Note: Forms a complete ring around the isthmus.

4. Palatopharyngeus

• Origin: Palatine aponeurosis and the hard palate.
• Insertion: Thyroid cartilage and the pharyngeal wall.
• Function: Lowers the soft palate and narrows the pharyngeal cavity.

5. Musculus Uvulae

• Origin: Posterior nasal spine of the palatine bone.
• Insertion: Uvula.
• Function: Elevates and thickens the uvula, assisting in the closure of the nasopharynx.

Interaction Between Tongue and Velum

• Palatoglossus Muscle:
  • Connects the tongue and velum, influencing their positions during speech.
• Velum Lowering:
  • Pulls the soft palate downward to assist in closing the velopharyngeal port during non-nasal sounds.
• Tongue Raising:
  • Elevates the back of the tongue towards the soft palate.

Methods of VPP Closure

• The VPP can be closed using various methods which affect oral and nasal sound production:

1. Trapdoor Method

• Involves the velum rising to form a seal with the rear pharyngeal wall.
• Key Muscle: Levator veli palatini.
• Commonly used by the majority of the population.

2. Circular Method

• Employs both the levator veli palatini and the superior pharyngeal constrictor to constrict the lateral pharyngeal walls.
• Used by about 20% of individuals.

3. Circular with Passavant’s Ridge (CPR)

• Similar to the circular method but includes Passavant’s ridge, utilized by 15-20% of people.

4. Sagittal Method

• Involves squeezing the lateral walls around the velum using the superior pharyngeal constrictors.
• Rare among individuals with normal VPP function.

Key Takeaways

• Each VPP closure method offers unique mechanisms and impacts speech differently.
• The choice of closure method may depend on anatomical variations and the necessity for precise oral and nasal distinctions.