1. What is microtia?
Congenital microtia is an abnormality in the development of the first and second gill arches in the early stages of embryonic formation, which results in the absence of a normal ear. Most children have varying degrees of hearing impairment and poor development of the middle ear, but the inner ear is mostly normal and relies on bone conduction to have some hearing. Patients may have other abnormalities in the development of the first and second parotid arches, such as the lack of development of the maxilla on the affected side, underdevelopment of the mandible or absence of the condyle. The onset of microtia is characterized by more males than females, more single cases than bilateral cases, and more right-sided than left-sided cases.
2. Microtia syndrome can be divided into three degrees according to the development of the auricle.
Degree Ⅰ, all parts of the auricle are still recognizable, there is a small auricular cavity and an auricular opening, only the outline is small and the inner surface of the auricular canal is often blind end.
In degree II, most of the structures of the auricle are not recognizable, the residual ear is irregular, peanut-shaped, boat-shaped and salami-shaped, and the external auditory canal is often atretic.
In degree III, the residual ear is only a small dermatome or in the shape of a mound, or there is only an ectopic earlobe.
A complete lack of development of the auricle, with no local traces, is called auricular malformation and is extremely rare.
3. Is microtia inherited?
It is not common for families to have a family history of significant microtia. Most patients with microtia do not find any genetic factors at play. Some patients’ mothers have a history of viral infections, radiation exposure, or drug use in early pregnancy, but in general, there is no clear cause for microtia, and no clear genetic factors have been identified. Modern medicine has not yet found enough evidence to prove the true cause of this disease.
4.When is the best time to treat microtia?
If left untreated, a deformed ear can affect the normal behavior patterns of children and can also seriously affect the psychological health of adults. The external ear reconstruction surgery requires the application of autologous rib cartilage as a scaffold for the reconstructed ear. If the patient is too young, the amount of rib cartilage is small and not enough for the surgical extraction of the external ear reconstruction. If the patient is too old, the rib cartilage becomes less elastic or even calcified, which is not conducive to sculpting the ear scaffold, and is often accompanied by serious psychological problems. Therefore, we believe that 6 to 14 years old (12 years old for girls) is the best age for surgery.
5.What is the treatment process for microtia?
Congenital microtia needs to be treated by auricular reconstruction, which usually requires 3-4 surgeries. The material used to make the ear can be either artificial material or autologous rib cartilage. Most artificial materials use Medpor (a linear porous high-density polyethylene material) as the ear scaffold, which has good histocompatibility, but is harder and has more complications such as post-operative scaffold exposure. At present, autologous rib cartilage is still the best material for sculpting ear scaffolds, so the application of autologous rib cartilage scaffold for ear reconstruction is the internationally recognized gold standard, and this is also the most commonly used surgical procedure in our department.
6. The internationally accepted methods of external ear reconstruction are as follows.
One-stage method of auricular reconstruction. In other words, a temporoparietal fascial flap is used to wrap the ear scaffold, and the surface of the temporoparietal fascial flap is implanted to reconstruct the auricle. The advantage of the one-stage method is that the surgical cycle is short and the outer ear reconstruction can be completed in just one surgery. The disadvantage is that the surgery is very traumatic, the reconstructed outer ear is bulky and the short-term shape is hardly satisfactory. Most patients will also require detailed trimming of the reconstructed ear.
Two-stage method of ear reconstruction. In the first stage, a “flat” ear is formed on the scalp and then lifted up six months later to form a “standing” ear with an otocranial angle (the angle between the plane of the ear and the plane of the skull, normal value is about 30°). This procedure requires a high level of skin in the hairless area behind the ear, such as a large enough area of skin in the hairless area. Although it is a short procedure, we have found that only a small percentage of Easterners are suitable for this procedure, while Europeans and Americans are more likely to use this procedure.
Skin expansion method of auricular reconstruction. It also usually requires 3-4 surgeries. The first procedure involves the placement of a 50-80 ml water bladder (also known as a skin soft tissue expander) in the mastoid area behind the pinna and a hospital stay of approximately one week. After the wound heals, saline is injected into the capsule until it is full. This takes about 2 months. Then you rest for 2-4 weeks and come back to the hospital for a second surgery. The second surgery removes the expander and cuts autologous rib cartilage to sculpt the ear scaffold to the size of the healthy side of the ear for auricular reconstruction. Some patients who require revision may have further detailing of the reconstructed ear 6 months after the second surgery. After these 2-3 delicate surgeries, the patient will have a realistic ear shape.
7. Are the reconstructed ears the same as the real ones?
It takes 3-6 months for the swelling to subside, for the color of the flap to return to normal, and for the subtle structure of the ear to become clearer. The reconstructed ear is formed by the growth of your own rib cartilage, and the skin on the surface is felt. Due to the limitations of modern medical technology, the reconstructed outer ear is a little harder than the real ear, but the shape is often faked.
8. What is the hearing of a patient with microtia?
In patients with microtia with external atresia, not only does the external auditory canal develop abnormally, but also the middle ear auditory tuberosity is often malformed, so there is a significant impairment in the air-conduction hearing, which is the dominant part of hearing. The inner ear is generally less involved, so bone conduction hearing is often unaffected. Patients with unilateral microtia have normal hearing in one ear and partial hearing in the other, so life and school are not greatly affected. Auricular reconstruction surgery should be performed first, and then later, as needed, a decision will be made to perform surgery to improve hearing. Patients with bilateral microtia with atresia of the external ear canal should be actively examined and treated for hearing impairment before speech is perfected to avoid missing the best time for treatment. There are now many built-in intelligent hearing aids that can be implanted at the same time as the outer ear reconstruction surgery, which greatly reduces the cost of treatment and is a blessing for patients with microtia with hearing deformity.
9. How to treat microtia with facial deformity?
Hemifacial hypoplasia is the most common concomitant deformity in patients with microtia. It is a congenital malformation in which the bone, muscle and other soft tissues centered on the ear, upper jaw and lower jaw are not developed properly. The incidence of hemifacial hypoplasia is similar to that of microtia. Because of the wide range of tissues involved, the manifestations of the deformity are variable and complex, and different patients require different treatment options. However, because this deformity gradually worsens with the patient’s development, early treatment is the better option. Our treatment principle is to first correct the deformity of the bone tissue with jaw lengthening technique, balance the structure of the craniofacial bone tissue, and then gradually improve the soft tissue deformity on this basis. If conditions are suitable, jaw lengthening surgery can be performed as early as 4 years of age.
10.What effect will microtia have on psychological development?
Patients with congenital microtia often exhibit low self-esteem, or social difficulties. One patient who is already in college told us that he grew up jealous of people with sound ears and sometimes had the urge to cut off other people’s ears. This is of course a very rare case, but we often find patients in our clinic with one kind of psychological problem or another. Therefore, we advise parents of children with microtia to take care of their children’s mental health and treat them as early as possible, not only by seeking help from plastic surgeons but also from psychologists if necessary. We should not only give the child a healthy ear, but also a healthy mind.
11.What do I need to pay attention to before and after surgery?
Pre-operative precautions.
(1) Do not take medication containing aspirin for two weeks prior to surgery, as aspirin can make the platelet clotting function decrease.
(2) Make sure you are in good health and free of infectious diseases or other physical inflammation before surgery.
Postoperative precautions.
(1) Ensure that the surgical site is clean.
(2) Avoid eating irritating foods such as chili peppers.
(3) Strictly follow the doctor’s orders for follow-up.