Deep coverage of front teeth
Introduction
Introduction to deep anterior teeth coverage Deep anterior teeth coverage refers to the maximum horizontal distance from the lower anterior cutting to the lower anterior labial surface exceeding 3 mm. This is a common clinical malformation, often accompanied by deep anterior teeth. basic knowledge Sickness ratio: 0.01%-0.02% Susceptible people: no specific population Mode of infection: non-infectious Complications: indigestion
Cause
Anterior deep covering cause
Bad habits (25%):
Long-term licking fingers, licking the lower lip and licking the upper front teeth and other bad habits, all give the upper anterior teeth a long-term lip-pushing pressure, it is easy to tilt the upper anterior teeth, while the lower anterior teeth Tilting, crowding, resulting in excessive anterior teeth coverage, long-term bad habits of the thumb, may cause abnormal jaw development.
Local disorders of the teeth or teeth (20%):
(1) congenital absence of the anterior teeth: clinically, there are 1 or 2 lower incisors missing to make the anterior segment of the lower arch smaller, resulting in lower arch retraction and deep anterior teeth coverage, which may be secondary to lower lip or mouth breathing habits. Make the deformity worse.
(2) Early loss of deciduous teeth: Early loss of lower molars can lead to smaller anterior segment of the lower arch, which increases the coverage of the anterior teeth.
(3) Multiple teeth: Multiple teeth in the anterior maxillary region can enlarge the dental arch or cause the upper incisor to be dislocated, resulting in excessive anterior deep coverage.
(4) abnormal order of the teeth: the upper second permanent molars erupted before the second permanent molars, or the first permanent molars erupted earlier than the first permanent molars, or the second permanent molars erupted before the upper permanent teeth, etc. Both may cause a distant position, and the front teeth are deeply covered.
Mouth breathing (10%):
Because the nasal respiratory diseases often cause partial obstruction of the nasal passages and replace them with mouth breathing, the breathing habits of the mouth are gradually formed. Over time, the lip muscles of the patients lose normal pressure due to relaxation, and the buccal muscles on both sides are elongated. The arch is compressed to make it narrow, forming a high arch with a sacral cover, and the anterior teeth are covered with a maxillary or dental arch.
Far ladder (5%):
The upper and lower deciduous teeth are in a distant relationship, causing deep coverage of the anterior teeth.
Systemic diseases such as rickets or calcium and phosphorus metabolism disorders (8%):
Muscle and ligament tension is weak, which causes the maxillary arch to narrow, the upper teeth and the distal and the wrong.
Genetic factors (10%):
The deep anterior teeth are often accompanied by obvious skeletal deformities, such as excessive maxillary development or hypoglossal development.
Prevention
Anterior deep cover prevention
About 25% of the causes of occlusal malformation are genetic factors, and most of the rest are caused by acquired environment. According to the survey, about 80% of cases are preventable, so prevention is very important. Prevention should start from the fetal period, mother During pregnancy, nutrition should be strengthened to enhance the physical condition of the fetus. Infants should be breast-fed in the infancy, so that the mandible can be used for proper mandibular advancement, and the muscles of the tongue, lips and cheeks can be coordinated to develop the maxillofacial muscles. The period is a period of vigorous growth and development of children. Not only should we pay attention to the proper improvement of diet and nutrition, but also pay attention to properly improve the hardness of the food, so that the structure of the child is fully stimulated and the chewing function is improved. In addition, it is also important to keep the mouth clean.
Complication
Anterior deep complication Complications, indigestion
It can cause psychological and mental disorders for patients, and if it affects chewing function, it can cause indigestion and gastrointestinal diseases.
Symptom
Pre-dental deep coverage symptoms Common symptoms Molar teeth are crowded with cartilage dysplasia and... Radioactive pain
Tooth type
The relationship between the upper and lower jaws and the cranial surface is generally normal, that is, the relationship between the molars is neutral, and the deep coverage of the anterior teeth is mainly caused by the dislocation of the upper anterior teeth or the dislocation of the lower anterior teeth or the combination of the two mechanisms. There is no obvious skeletal abnormality, and the prognosis of this type of deep coverage is good.
2. Functional type
Mainly caused by neuromuscular reflex caused by functional contraction or retraction of the mandible. The maxillary development is normal, and the posterior teeth are far-neutral. However, when the mandible is extended to the neutral molar, the relationship between the upper and lower jaw is basically Coordinating, the prognosis of this type of mismatch is not certain.
3. Bone type
Mainly due to the abnormal development of the upper and lower jaws, the upper and lower jaws are in the middle and the middle of the wrong relationship. The posterior teeth are mostly in the long-term relationship. According to the formation mechanism, they can be divided into three kinds of cases. The specific diagnosis can be combined with X-ray cephalometric analysis.
(1) The maxillary developmental protrusion and normal mandibular development.
(2) The maxillary development is normal, and the mandible is underdeveloped or retracted.
(3) The maxillary developmental protrusion, mandibular hypoplasia or retraction.
4. The coverage can be divided into 3 degrees according to the amount of deep coverage.
I degree deep coverage: the maximum horizontal distance from the upper anterior teeth to the lower anterior labial surface is 3 to 5 mm.
II degree deep coverage: 5 ~ 7mm.
Deep coverage of III degree: 7mm or more.
In severe cases, it can reach more than 10mm.
Examine
Examination of deep anterior teeth
Clinical examination
The relationship between the upper and lower jaws and the cranial surface is generally normal, that is, the relationship between the molars is neutral. The deep anterior teeth coverage is mainly due to the dislocation of the upper anterior teeth or the dislocation of the lower anterior teeth or the combination of the two mechanisms. There is no obvious skeletal abnormality.
Laboratory inspection
X-ray examination can be used to understand the specific depth of coverage of the anterior teeth. At the same time, blood tests can be performed to see if there is a co-infection.
Diagnosis
Pre-dental deep coverage diagnosis
The disease usually shows the developmental malformation of the teeth after birth. It is currently thought to be related to the genetics of the chromosomes. It is also believed that the mother is pregnant with drugs that are banned during pregnancy. Therefore, according to the clinical manifestations of this disease, it should be differentiated from congenital dysplasia, which can be differentiated from 21-trisomy syndrome. The latter can be distinguished by a feasible chromosome examination, and is usually accompanied by characteristic clinical manifestations such as penetrating palm.
