Dr.P.P.Lingam, M.s. (ENT), M.Ch., (Plastic Surgery)
Resident Smile Train Surgeon, Department of Plastic Surgery
The Smile Train Regional Centre, MMHRC.
Hearing Concerns in a Cleft Child:
Infants born with cleft palates and other craniofacial anomalies are likely to have more hearing problems than other infants. Problems with the middle ear are the most common among children with clefts. Approximately 35% of all children will have of least one middle ear infection by the age of three. Although comparable information is not available on children with clefts, a conservative estimate would be at least 80% of them will have had one or more of these conditions by the age of three.
Since hearing loss is a major cause of language learning problems, it is important to be on the alert for any signs of hearing impairment in a cleft child.
The Ear:
While hearing is a key factor in communication, possibly even more important is that it gives people a feeling of life participation and security. A sense of hearing is vital to well-being.
The normal human ear can distinguish among some four hundred thousand different sounds. The hearing mechanism perceives these and transforms and transmits these sound waves as a message to the brain. Before reaching the brain the sound has to pass through three well-defined sections of the ear namely the outer ear, middle ear and the inner ear.
The pinna of the outer ear is designed to help gather sound waves and funnel them down the ear canal to the ear drum. The ear drum vibrates when sound waves strike it which in turn transmits the sound to a chain of three small bones, the ossicular chain, in the middle ear. The three bones actually form a lever system that transfers the sound waves to the inner ear.
The Eustachian tube is the part of the middle ear that connects the middle ear cavity with the back of the throat (nasopharynx). The upper end is normally open because it is surrounded by bone. The lower end is normally closed, or collapsed, because it is surrounded by soft tissue. The tube opens every third time we swallow or yawn, allowing air pressure in the middle ear to equalize with the outside air pressure.
The last bone in the assicular chain, the stapes, is attached to a tissue membrane called the oval widow. When the stopes moves, the oval window. When the stapes moves, the oval window moves with it transmitting the sound waves to cochlea in the inner ear. The cochlea is a fluid filled channel. Inside the cochlea are thousands of microscopic hair like cells that are set into motion when ever the fluid is disturbed by the sound waves. Stimulation of these cells, in turn, causes electrical impulses to be sent to the brain.
Hearing Problems:
More children with cleft palates suffer decreases in hearing than do similar group of children without cleft palate. Since it is very difficult to see the eardrums in small infants, the physician and parents may not be initially aware of the presence of ear disease.
The part of the ear, of most concern in the child with a cleft palate is the middle ear. The Eustachian tube serves three physiological functions for the middle ear.
- Ventilation (Balancing air pressure between the middle ear and nasopharynx)
- Protection (From secretions and pressue)
- Clearance (Draining middle ear secretions into the nasopharnyx)
The muscles that help the Eustachian tube function properly are connected to be soft palate. In the cleft palate child, these muscles are abnormally attached to cleft margin and back of hard palate. So they done’t operate efficiently, thus interfering with the ability of the Eustachian tube to drain fluids from the middle ear. A build up of fluids from the middle ear. A build up of fluids in the middle ear interferes with the movement of the ossicular chain and thus cause hearing problems. If the fluid pressure becomes too great, it may cause perforation in the ear drum. If the fluid gets infected it may lead to ASOM (Acute Supportive Otitis Media) or CSOM (Chronic Suppurative Otitis Media).
It is not understood fully why a cleft child is particularly susceptible to such problems. One reason may be malfunctionin of the Eustachian tube due to the abnormally placed soft palate muscles.
It is also possible that a cleft makes it easier for infectious agents such as bacteria and viruses to get into the Eustachian tube and cause inflammation which may cause Eustachian tube obstruction.
That’s the bad news. The good news is that these problems can be treated successfully if they are identified early. It is also good to know that with certain precautious these problems can be prevented. Finally, most children will become less susceptible to otitis media as they grow older.
Identifying Ear Problems:
Early detection of ear problems makes them easier to treat. Because it is impractical to have a physician check a child’s ear once a week or even once a month, it is important that parents are able to recognize the early signs of possible trouble. Constant crying or frequent rubbing or pulling of ears, may indicate pain or discomfort caused by middle ear problems. If the child does not participate in play activities or makes noises in response, it may be a sign that there is hearing problems. Proper feeding of baby with baby held at 450 angle will also prevent fluids from entering middle ear. Lastly if any ear discharge is seen in the cleft child, the parents should immediately (Grommet insertion, tympanoplasty, etc.) can prevent complications of ear problems.
Diagnosing Ear Disease:
These are many tests for diagnosing ear disease particular problem in cleft children is their compliance and cooperation while performing the test. In MMHRC for assessment of middle ear function we have the latest Digital Impedance audiometer which tests the middle ear condition. By just plugging in the ear plug into the ear the instument automatically tests the middle ear function and for documentation gives a graphic printout. It is an objective hearing test that does not require the child’s active participation.
To objectively see the movement of soft palate while phonation and also to see the opening of Eustachian tube we have a fibrooptic nasopharyngoscope. The outer diameter of the scope is just 3 mm which is small enough to be introduced into the child’s nose. Post operative video recording of nasopharyngoscopy is done in all patients’s who have undergone palatoplaty to check for Velopharyngeal incompetence. Otoscopy is also done in all children with cleft palate to see the state of Tympanic Membrane.
Conclusion:
To conclude there are several important things to remember about ear problems of children with cleft.
- These children are more prone to get ear problems which can result in mild to moderate hearing loss.
- Parents should carefully be on the look out for signs of ear problem.
- An audiologist can provide professional help in identifying ear problem and help in giving special services as per the child’s needs.
- Finally with early detection such problems can be successfully treated.