Congenital microtia

Introduction to congenital microtia Congenital microtia, or congenital external middle ear malformation, manifests as severe auricle dysplasia, external auditory canal atresia or stenosis, middle ear malformation, and inner ear development is mostly normal, with certain hearing through bone conduction. The clinical features of patients with congenital microtia are mainly in the auricle, external auditory canal and middle ear, and the inner ear is often not affected. It needs to be treated by reconstruction of the whole ear and reconstruction of the hearing function. The treatment of congenital microtia is mainly composed of two aspects, one is the reconstruction of the outer ear and the other is the reconstruction of the hearing function. Generally, the foreign ear is re-created, and then the function reconstruction is performed. The normal auricle is composed of thin skin soft tissue wrapped elastic cartilage stent, which has elastic thin shell structure, and is composed of ear wheel, pair of ear wheel, tragus, tragus, earlobe, ear arm, triangle socket, boat socket, etc. The composition, the convex and concave convolution, the complex shape, so the reconstruction of the auricle is a difficult and complicated operation. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: cleft palate hydrocephalus hip dislocation

Congenital small ear malformation

Environmental factors (30%):

Environmental factors in the early pregnancy of the mother due to viral influenza, excessive pregnancy reaction, toxic substances in home decoration are all factors that may lead to the occurrence of microtia.

Genetics (20%):

The incidence of recent reports in China is 5.18/10000. More men than women (2:1), more common in the right side of the deformity, bilateral deformity is about 10%. The genetic prevalence of patients with a family history of small ear malformations ranged from 2.9% to 33.8%.

Embryology

The auricle originates from the first zygomatic arch (the lower jaw arch) and the second zygomatic arch (the lingual arch). At the 5th week of the embryo, part of the zygomatic arch will develop into the auricle, which is roughly formed during the 5th to 9th week of the embryo. At the 6th week of the embryo, the ectoderm and mesenchyme appeared in the mandible and prosthetic arch after activation and proliferation, and 6 hillock-like ridges appeared. The 1, 2, and 3 hillocks appeared in the tail of the mandibular arch, and later formed the tragus and the ear wheel. The upper part of the foot and the outer ear wheel, 4, 5, 6 hillocks appear in the head of the hyoid bone, which develops into the ear wheel, the tragus and the earlobe. The 6 hillocks are fused to form a raised auricle, and the first cleavage is inwardly recessed to form the external auditory canal. During the development of the auricle, the embryo is affected by genetic or external factors, and it is prone to various developmental abnormalities of the auricle.

Experimental studies on auricle embryo development have been around for many years, but the current mechanism remains unclear. The role of Cranial neural crest cells (CNCC) in the development of the ear has gradually attracted people's attention. CNCC is a multi-differentiation potential stem cell, which is the main cellular component of mesenchyme in the first and second zygomatic regions. An important feature of CNCC is its migration. The study found that rupture of the radial artery during auricle development in mice caused microtia deformity, and CNCC did not have migration. Vitamin A is given early in pregnancy to interfere with the migration of CNCC.

Genetics

Congenital microtia can occur either alone or in part of the syndrome. Common combinations include: Treacher Collins syndrome, Goldenhar syndrome, Nagar syndrome, and Miller syndrome.

The susceptibility gene localization and identification of congenital microtia is a hotspot and a difficult point in current research, but no research results have been reported so far.

The incidence of congenital microtia is reported in different literatures, and is related to race and region. The incidence of recent reports in China is 5.18/10000. More men than women (2:1), more common in the right side of the deformity, bilateral deformity is about 10%. The cause of the small ear malformation is still clear. It is generally believed to be the result of a combination of environmental and genetic factors. Environmental factors may cause small ears in the early pregnancy due to viral influenza, excessive pregnancy reaction, and toxic substances in home decoration. The incidence of malformation, the family history of small ear malformations, the genetic prevalence of roughly 2.9% -33.8%.

Congenital microtia prevention

One,

(1) Perform a conscious physical exercise. Improve the body's immune function and disease resistance, especially women of childbearing age, to reduce the serious harm of cytomegalovirus to the fetus.

(2) For pregnant women or patients with chronic wasting diseases and low immunity, they should pay attention to protection and keep them away from the source of infection.

(3) Pay attention to environmental hygiene and food hygiene.

Second, to prevent influenza, in addition to flu vaccine, you should also pay attention to personal hygiene habits:

1. Pay attention to personal hygiene, develop good personal hygiene habits, wash hands frequently, take a bath, do not share towels, cups and other daily necessities, so as not to spit, in order to prevent contact with the spread of influenza virus.

2, the room and the office, should always be ventilated, reduce the number of bacteria and viruses gathered indoors, keep the indoor fresh air.

3, the disease epidemic should be avoided as much as possible in public places, such as shopping malls, cinemas and other crowded places. Keep a distance of more than 1 meter from those who sneeze.

Congenital microtia complications Complications, cleft palate, hip dislocation

There can be no brain malformations, which can be accompanied by deformities in other parts of the body, such as cleft palate, cervical spina bifida, narrow chest, imbalance of upper and lower limbs, lack of humerus and thumb. Almost all of them are accompanied by too much maternal amniotic fluid. Common malformations with spina bifida are hydrocephalus, deformed foot, skull cavity, meningocele, brain swelling, cleft lip, congenital heart disease. Prone to nutritional ulcers, gangrene, muscle contracture, hip dislocation, clubfoot deformity, often incontinence.

Congenital microtia symptoms Common symptoms Double auricle dysplasia External ear canal stenosis Deafness cup ear

The clinical features of patients with congenital microtia are mainly in the auricle, external auditory canal and middle ear, and the inner ear is often not affected. According to the degree of deformity, the most commonly used type in clinical is type III:

I degree: the size and shape of the auricle change, but the important surface marker structure of the auricle exists, the external auditory canal is narrow, and the external auditory canal is blocked when severe.

II degree: the most typical, only the vertical direction of the ear wheel, the sausage shape, the external auditory canal.

III degree: only the agglomerates of skin and cartilage remain, and there are no ears in severe cases.

Examination of congenital microtia

First, laboratory inspection

1, blood test: peripheral blood leukocytes significantly increased, suggesting concurrent infection.

2, cerebrospinal fluid examination: cerebrospinal fluid white blood cells significantly increased, suggesting intracranial infection.

Second, auxiliary inspection

1. The skull X-ray film can show the relationship between the cranial fissure and the cranial suture and the main intracranial sinus.

2. CT and MRI can display the contents of the capsule. CT and MRI scans can reveal the bulging of the spinal cord, spinal nerves and meninges, as well as local adhesions.

3, the spine X-ray film shows the absence of laminar spine, the pedicle spacing is widened, the bone defect site is connected with the soft tissue mass.

Diagnosis and diagnosis of congenital microtia

diagnosis

Diagnosis can be based on medical history, clinical symptoms, and laboratory tests. There are more than ten types of middle ear developmental disorders in patients with congenital microtia, mainly for the developmental malformations of the small bone, tympanic muscle and facial nerve, and are closely related to the severity of external ear malformation. Congenital external ear malformations can be manifested as one of the clinical signs of serial signs in severe cases, such as the Oculoauriculovertebral spectrum (OAVS). In addition to the presence of small ear malformations, the patient also suffers from a short half-face (sacral, maxillary or mandibular dysplasia), soft tissue malformation (anterior or anterior auricular deformity), orbital defect (orbital defect, conjunctival epithelial cyst), spine Malformations, as well as congenital kidney and heart defects.

Differential diagnosis

No need to identify.

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