DR.NUAS HASAB JAFAR Morbid anatomy and pathophysiology in the cleft palate

Anatomy and physiology In approaching any surgical problem, one must have understanding of both normal and abnormal anatomy

the muscles form opposing slings that meet in the soft palate raphe. The tensors and levators form the superior sling.palatoglossus and palatopharange us form the inferior ones.

there are velar elevators and velar depressors The levator veli palatini is the primary elevator of the velum. It originates from the petrous portion of thetemporal bone, and inserts into the palatal aponeurosis palatalaponeurosis Another elevator is the musculus uvulae Contraction of this muscle shortens the soft palate, basically bunching it up towards the back.

Depressors are the two palatoglossus muscles and the palatopharyngeus muscles. The palatoglossus originates from the palatal aponeurosis and inserts into the sides of the back of the tongue Contraction both elevates the tongue and depresses the velum.

They interdigitate with its partner on the opposite side in the midline of the soft palate this muscle doesn't elevate the velum at all. It's sole function is to open the Eustachian tube to allow the air pressure in the middle ear to equalizeEustachian tube And the last muscle is the tensor veli palatin

In reality, the velum does not move like a hinged trap door but is only the anterior part of a complex velopharyngeal valve which functions as a circular sphincter

` * So here's a little physiology note: When at rest, the velum is depressed, allowing us to breath through our nose comfortably. So why do we need velar depressors? Well, the velum is elevated most of the time during speech (or singing), but when we want to make nasal sounds, like /m/ /n/ or nasal vowels, we've got to depress it very quickly. This is where the depressors come in, especially the palatoglossus. Allowing the elevators to simply relax would be too slow for comprehensible, flowing speech.

. Seal off the nasal from the oral cavities in order to isolate the oropharyngolaryngeal tract from atmospheric pressure during deglutition, producing a partial vacuum to facilitate compression of the food bolus by the tongue, cheeks, and pharynx, and therapy forcing it into the esophagus. Open the Eustachian tube It is very important for the Eustachian Tubes to open (when swallowing) so that pressure in the middle ear can be equalized with the pressure in the atmosphere

if the tensor Palatini muscles don't contracted The Eustachian Tubes would not open therefore the middle ear pressure cannot be equalized. With a cleft of the soft palate, the Levator Palatini from each side cannot interdigitate. As a result, the velum cannot elevate.

Effects on Feeding : Difficulty in forming negative pressure as air leaks to and from the nasal cavities. Nasal regurgitation of milk, liquids, vomit, solids Effects on Hearing Eustachian Tube dysfunction occurs in % of cases due to lack of interdigitation of the Tensor Palatini muscles. This results in chronic and recurrent otitis media and conductive hearing loss

... Effects on Speech and Resonance Difficulty building up positive pressure for high pressure sounds Hypernasality of vowels Nasal air emission of consonants Effects on Language Development Language may be delayed secondary to chronic otitis media and conductive hearing loss

: closing of cleft palate should provide a mechanism for normal speech,hearing,dental occlusion,swallowing,and separation of the oral and nasal cavities without interfering with facial bone grouth.

Thank you