What are the reasons why children do not have teeth?

Teething is a process that children must go through as they grow. Generally speaking, children start to grow teeth after they are one year old. However, some children fail to grow teeth during their development, which troubles many parents. Generally speaking, children do not grow teeth due to their physical constitution, Williams syndrome, cleidocranial dysplasia, mucopolysaccharidosis, Dylan's syndrome and other diseases. A detailed introduction will be given below!

1. Personal physique

This is normal individual difference and is the most common situation. The time of teeth eruption can be as slow as after one year old, or even around one year and three months old. Or a few teeth may grow normally at first, and then there will be no movement for a long time, delaying the sequential teeth eruption schedule. However, overall examination showed that the child's growth and development were good, and his intelligence development was also normal, so it can be judged that this is a normal physiological phenomenon. The families of these children may have had similar situations when they were young, which is a family hereditary constitution.

2. Williams syndrome

It is a congenital disease caused by a partial defect in the 7q11.23 segment of the long arm of chromosome 7. Children with this disease have a typical facial appearance, a thin body, mild to moderate intellectual developmental delay, and their teeth usually grow slowly and are small and sparse. A friendly and talkative personality is also another characteristic of them. Children with this disease often have congenital heart disease, especially aortic stenosis, pulmonary artery stenosis or pulmonary valve stenosis.

3. Cleidocranial dysplasia

Babies with this disease not only have slow-growing teeth or even lack some teeth, but are also usually short in stature, with a prominent forehead and back of the head, and their clavicle, which is located at the junction of the neck and chest, is underdeveloped or completely absent, so the shoulders of the sick child can be close together. This is a dominant genetic disease. The gene defect is currently known to be located at 6p21 on the short arm of chromosome 6 and can be confirmed by molecular biological examination. The patient's intelligence is completely normal.

4. Mucopolysaccharidosis

Especially for children with mucopolysaccharidosis type 2 and type 6, their teeth often grow more slowly. Since this is an acute hereditary congenital metabolic disorder, mucopolysaccharides slowly accumulate in various parts of the body, especially in bones, joints, hair, skin, teeth, and internal organs, forming a very special appearance and claw-like hands caused by bone and joint deformation, spinal abnormalities, and short stature. It is necessary to seek medical treatment as soon as possible.

5. Dylan's syndrome

It is a rare congenital abnormality. The growth and development of children are extremely poor. They have small heads, faces, hands and feet, and bodies. Their faces are hairy and have typical features. Almost all of them have severe growth retardation and intellectual disabilities. Their teeth grow surprisingly slowly and they often have missing teeth. The prognosis of this disease is poor, and the only treatment is symptomatic treatment plus rehabilitation to prevent the condition from worsening too quickly.

6. Congenital premature skull fusion syndrome

The more typical ones are Crouzon's syndrome and Yebote's syndrome. In addition to the special facial and head shape manifestations caused by premature fusion of skull sutures, it is often accompanied by abnormal tooth development, joint abnormalities or hearing impairment. Most of them are chromosomal dominant genetic diseases, and most of them are caused by new mutations. When the patient grows up and wants to have children, there is a 50% chance that he or she will give birth to a child with the same disease. Therefore, in addition to receiving special treatment, genetic counseling should also be performed. The gene defect is mainly a point mutation of the fibroblast growth factor receptor (FGFR2).

7. Progeria and progeria-like diseases

The characteristics of this type of disease are that except for slower growth and development and late eruption of teeth in infancy, everything else is normal. However, at around two years old, growth retardation, intellectual development disorders, rapid aging and degeneration of the physiological state begin to appear, leading to premature death. The cause of the disease may be related to defects in the gene repair system.

8. Congenital German measles syndrome

This is a congenital infection of the fetus that is gradually decreasing. If the mother gets German measles within the first three months of pregnancy, there is a high probability that the fetus will be infected, which will have adverse effects on its teeth, bones, eyes, brain, heart, and hematopoietic function. In severe cases, the fetus often dies in the womb, and those who survive by chance also have complications and require long-term follow-up treatment and rehabilitation.

9. Other rare congenital diseases

Diseases such as ectodermal dysplasia, oto-patodigital syndrome type 1, incontinence pigmenti, Dubois syndrome, Goetz syndrome, and X-chromosome excess syndrome may all lead to slow tooth growth or missing teeth and must be carefully checked.