Small jaw

Introduction The mandibular developmental disorder is characterized by jaw retraction and small jaw state, commonly known as "short chin". The anterior teeth are deeply covered, and the posterior teeth are misaligned in the distal direction, making the maxillary anterior jaw and nose appear too prominent. A "bird's beak"-like deformity appeared.

Cause

(1) Causes of the disease

The cause has not been fully elucidated and is associated with a variety of environmental factors, and has recently been shown to be associated with intracellular fetal cell inclusion body virus infection.

(two) pathogenesis

Small jaw deformity is generally thought to occur in the first 4 months of the embryo, caused by interference suppression in the center of the mandibular condyle, and malnutrition during pregnancy, certain drugs during pregnancy, radiation and certain toxin poisoning can be induced All kinds of malformations, including cleft palate and tongue droop triad, Douglas observed that if you can get adequate nutrition after birth, the small jaw deformity can develop to near normal within 6-8 months. Despite this, the true cause of the disease is still unclear and there is no sufficient evidence of genetic factors.

It has recently been confirmed that this malformation is associated with intracellular fetal cell inclusion body virus infection. The infection of the virus can occur from the fourth week of pregnancy to the end of pregnancy. The infected mothers are mostly young primiparas. The clinical signs of the mother may not be obvious. The virus infects the fetus through the placenta. The more the infection occurs in the early pregnancy, the more severe the fetus is affected.

an examination

Related inspection

M-mode echocardiography (ME) Doppler echocardiography

diagnosis:

1. Bird-like face: This symptom has a typical "bird-like face" with a small jaw.

2. Cleft palate: The incidence of cleft palate is about 50% to 68%.

3. The tongue is drooping: the tongue is drooping and the respiratory tract is blocked. Under normal circumstances, the tongue root depends on the traction support of the mandibular ligament combined with the mandibular condyle, so it can be in the anterior position. When the small jaw is deformed, the tongue root loses its support and the sag occurs. The oropharyngeal gorge is blocked and blocked, which causes airway obstruction. Due to airway obstruction and breast-feeding disorders, the child can make a modern insufficiency to enhance the inspiratory action and sucking force, so that the negative pressure in the hypopharynx and the chest esophagus is increased, forcing the tongue root to sag further. At the same time, a large amount of air enters the stomach, which can cause nausea. The volume of vomit is inhaled into the lower respiratory tract, causing aspiration pneumonia or atelectasis. The degree of obstruction of the respiratory tract of this symptom can be very different. In mild cases, there is inspiratory wheezing in the supine position, while the airway is basically unobstructed when awake or crying: the breathing is blocked and there are many silent sputum, its wheezing and throat source Different sex.

4. Cardiovascular lesions: About 20% of cases have cardiovascular malformations, such as patent ductus arteriosus, atrial septal defect, aortic coarctation, right heart and so on. Pulmonary hypertension and pulmonary heart disease can be caused by upper airway obstruction.

5. Others: The symptoms may be accompanied by eye defects, skeletal deformities, auricular malformations, deafness caused by abnormal structure of the middle ear and inner ear, hypertrophy of the proliferator, congenital heart disease and mental retardation.

Typically, inhalation of respiratory infarction from birth, sometimes accompanied by laryngeal wheezing, cyanosis, ribs and sub-sternal inhalation depression, due to mandibular dysplasia and cleft palate, and large occlusion of the tongue, and Caused by a backward sagging shift. Because the symptoms are even worse in the supine position, such children often have difficulty in feeding, are not easy to suck and swallow, and are prone to coughing, resulting in malnutrition, weight loss, and slow growth.

Due to chapped, food is easy to break into the trachea and eustachian tube, so it is easy to have aspiration pneumonia and otitis media.

The symptoms can be diagnosed according to the above clinical features.

Differential diagnosis

Differential diagnosis of small jaws:

1, mandibular retraction: mandibular retraction is due to mandibular hypoplasia or congenital absence of lower anterior teeth and pterygopalatine dysfunction caused by a mandibular retraction of malocclusion.

2, facial muscle atrophy: facial muscle atrophy refers to dystrophic striated muscle, muscle volume is smaller than normal, muscle fibers become thinner or even disappear. Neuromuscular disease is hypertrophy. In addition to the pathological changes of muscle tissue itself, muscle nutrition is closely related to the nervous system. Spinal cord disease often leads to muscular dystrophy and muscle atrophy.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.