The ear is comprised of three sections: the outer, middle and inner ear. The outer ear captures sound and funnels it to the middle ear. The ear drum (or tympanic membrane) separates the outer ear from the middle ear. The middle ear contains three small bones known as ossicles and named the malleus, incus and stapes. These vibrate and transfer sound into the inner ear where the auditory nerve is located. The auditory nerve transmits the information to the brain.
A baby is born with the ability to hear. However, growth continues until approximately 7 years of age.
Function of the Eustachian Tube
The Eustachian tube connects the middle ear to the nasopharynx. This allows pressure to be adjusted in the middle ear so that damage does not occur. The Eustachian tube is normally closed at the nasal end, but it can be opened by lowering or protruding the jaw. This is the reason why chewing gum when flying helps to keep your ears from popping. The Eustachian tube equalizes pressure.
Differences in the Eustachian Tube in Babies vs. Adults
The Eustachian tube doubles in length from birth to approximately 7 years of age. Additionally, it becomes significantly more vertical. This length and slope allows the Eustachian tube to function more efficiently, allowing better equalization of pressure and drainage from the middle ear.
Otitis Media
According to Medline Plus, a service of the National Institutes of Health, "ear infections are the most common illness in babies and young children." The National Institute on Deafness and other Communication Disorders concurs, stating that, "Three out of four children experience otitis media by the time they are 3 years old."
With otitis media, fluid becomes trapped in the middle ear. The Eustachian tubes become inflamed and swollen and do not drain the fluid. Additionally, adenoids, which are larger in children than in adults, swell as well blocking the Eustachian tube. Because the tube is short and straighter in children, this problem is more prevalent.
Environmental Factors
There have been a variety of studies investigating environmental causes of otitis media in children. Many physicians indicate that breast-feeding is preferred to bottle feeding. The position in which a baby is held during breast-feeding allows for better function of the Eustachian tube. Additionally, a baby should not be put to bed with a bottle, because of the positioning. There is, however, limited scientific research in this area.
Children in day care as opposed to homes seem to have a higher incidence of otitis media because they are exposed to more germs. Again, scientific research is lacking to support this claim.
Secondhand smoke has also been linked to higher incidents of otitis media. While there is scientific research regarding the dangers of secondhand smoke for children, more research is needed to provide causal linkage between secondhand smoke and otitis media.
Tubes
According to the American Academy of Otolarygology Head and Neck Surgery, "each year more than half a million ear tube surgeries are performed on children, making it the most common childhood surgery performed with anesthesia." Tubes are inserted into the tympanic membrane to allow air into the middle ear. This allows pressure to be equalized in much the same way that the Eustachian tube should. The tubes will normally come out automatically.
