-
Then, the tooth grows to a certain extent and begins to establish an occlusion. The teeth are replaced one by one, not all the teeth at the same time, so the height of the jaw is basically unchanged. When the permanent teeth grow to the point where they make occlusal contact, they are basically immobile.
First of all, one of the causes of tooth eruption is the development of the tooth root. The tooth germ becomes a crown, and then the root of the tooth is generated, and when the root develops to two-thirds of the length of the root, it begins to break the gingiva and erupt, and the root continues to develop until it is completed two years after eruption, and the root continues to grow in the direction of the alveolar bone, pushing the crown to continue to erupt into the mouth.
Licking or not licking teeth has no effect on the height of tooth eruption, but it does have an effect on the direction of tooth eruption, which can lead to misaligned teeth due to the bad habits of the tongue. <>
The first is determined by genetics, the development of bone type is greatly affected by heredity, most of the children of the parents have a square face, and most of the children of the parents have a long face. The so-called face length and shortness (that is, square) refers to the steepness of the angle of the jaw plane, from the side, the steeper the mandibular plane, the longer the face, on the contrary, the shorter the face, the more square the front, the longer the face, the greater the height of the jaw, the greater the height of the tooth eruption, the shorter the face, the smaller the height of the jaw, the smaller the height of the tooth eruption. <>
The second is influenced by environmental factors. Enlarged adenoids in your child may cause frequent mouth breathing, causing the face to grow. On the other hand, the environmental factor means that the forces of the muscles inside and outside the mouth are balanced, and if the muscles of the mouth are closed (such as the masseter muscles, which have a strong bite force, the masseter muscles are developed) are stronger than the muscles that open the mouth (such as the tongue muscles, against the mouth, the mouth tends to open), the height of the jaw will be reduced until the balance is re-established; The closed mouth muscles are weaker than the open mouth muscles, which increases the intermaxillary height.
But in the end, it was balanced, and the intermaxillary height was determined. So the tooth erupts and the bite makes contact. At this time, the development of the tooth root is just completed or is about to be completed.
In addition, if a tooth is missing for a long time, there is no occlusal contact with the jaw teeth, and it will elongate, causing occlusal interference. Such "eruption" has little to do with root development, but may be related to the contraction of periodontal fibers. However, it is clear that occlusal contact has an important impact on maintaining tooth eruption height.
Finally, the morphology (length, shape) of the teeth is genetically determined, and each tooth has a fixed shape, with the incisors being trapezoidal and the canines being pentagonal. The entire mouth opening is wedge-shaped, so in terms of crown length alone, it is normal for the crown of the posterior teeth to be short and the crown of the anterior tooth to be long.
-
According to medical research, there is a pulp cavity in the middle of the dentine of every tooth. When teething, the lower part of the pulp cavity is open, and the blood vessels and nerves can pass through, and then the dentin cells in the pulp cavity can continuously obtain nutrients, secrete dentin, and make the teeth grow. When it grows, the lower end of the pulp cavity is closed and the tooth stops growing, while the pulp cavity of mice is not closed and can grow for life.
-
This is the characteristic of human beings, teeth are generally replaced only once in a lifetime, and they will stop after a certain period of time.
-
Because if the teeth continue to grow at this level, it will endanger people's normal life.
-
The length of a tooth is generally determined by an individual's genes, so it's a genetic problem.
-
This is just a law of nature, and there is no need to dwell on why it must be the case.
-
The eruption of a tooth does not necessarily have a uniform rate, and some of it is phased. Sometimes it is also related to one's own physical condition.
-
Generally, the tooth will not grow after two tooth changes, and it is mature by this time.
-
This is the same as the human skeleton, which can be said to be an exoskeleton that grows to a certain extent and stops growing.
-
If the teeth continue to grow, they will shoot straight out of your head, how dangerous it is.
-
If it's longer, your lips won't be able to wrap around your teeth.
-
Analysis: At the age of 16 to 24, at the age of human wisdom, at the end of the upper and lower left and right dental arches, the last permanent tooth - wisdom tooth grows, and the human tooth growth ends.
Advice: In medicine, wisdom teeth are also called third molars, that is, the eighth tooth counted from front to back. Wisdom teeth are the last four of the 32 permanent teeth in humans.
Groupers are hermaphrodites, and as individuals grow, sexual transformations can occur, generally first female and then male, and it is not easy to distinguish between male and female before the gonads are immature. Spawning starts in March every year, and it has the characteristic of spawning multiple times.
Landlord: I'm also a fan of Raul To be fair, Spain and Real Madrid won't necessarily win the championship without Raul, and Spain and Real Madrid won't necessarily stop in the top 8 without Raul Of course, losing is never Raul's problem. Raul's contribution to Spain and Real Madrid needs not be said much Brother's recent performance at Real Madrid has been really good Goals speak for it The Spanish national team has a lot of talent now Raul may be a little older There is a reason why he was not selected for the national team As a fan of Raul There is no need to argue about these A person cannot be liked by everyone The same goes for Raul As long as we support him psychologically all the time Raul come on!
In fact, there is no certain thing, and there are those who do not get married. But it is easy to drift away from the mainstream of society. >>>More
The sound in the case, depending on what the characteristics are. If it is an intermittent "click" sound (but not loud), it may be the sound of the hard disk reading, and you can't do anything about it, except for the backup of important files, you can ignore it. If it's a continuous "roar" like a motor, it's probably the sound of a fan. >>>More
Orthodontics is not only about aligning the teeth, but also about designing the curvature of the laughing line according to the facial features. The most important thing is to improve the occlusal function of the teeth, that is, to adjust the abnormal relationship between the upper and lower jaws, between the upper and lower teeth, and between the teeth and the jaws. >>>More