Anatomy

Closure of the hiatus between the soft palate and the pharynx is largely dependent upon movement of the soft palate posteriorly and superiorly. However, the walls of the surrounding pharynx also may contribute to closure resulting in one of three closure patterns:

• coronal: palate moves to posterior pharyngeal wall
• sphincteric: palatal, lateral and posterior walls move
• sagittal: lateral pharyngeal wall adduction largely results in closure

The soft palate is moved and shaped into position by three muscles:

• levator veli palatini
• horizontal fibres of palatopharyngeus
• musculus uvulae

Closure of the pharynx, which may occur at a level below the hard palate, predominantly is driven by contraction of the superior constrictor muscles. Excessive contraction of the upper fibres of superior constrictor may produce a surface 'band' to compensate for poor closure that has been termed "Passavant's ridge".