——"World Orthodontic Health Day" Oral Health Care Series Science Popularization (2)
Zeng Juan, Department of Stomatology, Characteristic Medical Center (formerly 306 Hospital).
Edited by Liu Yan/Cui Yan, Medical Science Popularization Center
It is rumored that the "black triangle" and the braces face are the two major killers of orthodontics, causing countless harms, and people will be planted under their hands if they are not careful. Although the braces face is menacing, we still have a chance to recover after being hit, but the "black triangle" is a trick, hurting people invisibly, and it is difficult for anyone who is hit to heal.
Is there any way to avoid the assassination of the Black Triangle? The so-called knowing oneself and knowing one's opponent is invincible. Today, we will unveil the full face of the killer "Black Triangle" for you.
The name "Black Triangle" is the name of the flower given to it by our braces, and its real name was originally called the open interdental wedge, which actually means that although the most protruding points of adjacent teeth are in contact with each other, the gums between them cannot completely cover the gap between the contact point of the two teeth and the neck of the tooth. This creates a triangular void that looks hollow black, hence the name "black triangle".
The "black triangle" will reduce the aesthetic value, resulting in exposed tooth roots, loss of periodontal support tissue, food impaction, bacterial accumulation, and more difficult oral cleaning, which will further affect periodontal health.
In the final analysis, where did the "black triangle" come from?
The direct cause of the formation of the "black triangle" is the vertical distance between the contact point between adjacent teeth and the alveolar ridge. When the vertical distance from the top of the alveolar ridge to the point of contact is less than or equal to 5 mm, there is almost no black triangle; When this value is 7 mm, nearly half of the patients will have a black triangle; When the value is greater than 7 mm, most patients will be attacked by a "black triangle". It can be seen that the contact point between adjacent teeth is too high and the height of the alveolar crest is reduced, which are two important factors leading to the occurrence of black triangle.
Conditions such as the length and narrowness of the crown and the tilt of the tooth root can lead to too high contact points between adjacent teeth; Conditions such as gingival recession and alveolar bone resorption can lead to a decrease in the height of the alveolar crest.
Let's start with the contact points of adjacent teeth, and the labial surface of the crown can be divided into square, oval, and pointed. The probability of black triangle occurrence is relatively low in square round teeth, while the pointed round teeth are relatively long and narrow, and it is believed that the tooth contact point is relatively high, and it is more likely to have "black triangle". The more dispersed the roots, the greater the probability of the occurrence of the "black triangle", and the more parallel the roots, the more the contact point moves towards the root, and the closer it is to the alveolar crest, the smaller the probability of the occurrence of the black triangle. Alveolar bone loss and gingival recession can lead to a decrease in the height of the alveolar crest. In addition, their causes are also related to age, periodontal inflammation, and thin periodontal biotype, which are also one of the main causes of the formation of the black triangle.
Speaking of this, some people can't help but feel a little incomprehensible. Let's talk about it simply, to prevent the "black triangle", for doctors, reasonable afterburner is needed in the correction process to prevent gingival recession and root resorption caused by improper afterburner, and at the same time can effectively control the movement of teeth, ensure that the roots are parallel after orthodontics, and avoid root tilting or root dispersion.
For patients, the first thing is to find a good doctor, and it is especially necessary to pay attention to oral hygiene during the orthodontic process. In addition to toothbrushes, it is also necessary to learn to correctly use interdental brushes, oral irrigators, dental floss and other auxiliary cleaning tools, and carry out comprehensive cleaning of teeth with all kinds of weapons, so as to avoid periodontal disease caused by plaque accumulation and minimize the probability of "black triangle".
In short, the "Black Triangle" is a preventable but difficult to reverse guy, although there are examples of braces enjoying the "Black Triangle" self-recovery, but not everyone is so lucky, the most important thing is to do a good job of prevention.
If there is an irreversible "black triangle", the first step is to strengthen cleaning to prevent it from continuing to deteriorate, and later you can also change the tooth shape by proximal surface enamelment, increase the contact area between teeth, cooperate with orthodontics to close the gap, or cover up the "black triangle" area by resin filling.
(The picture comes from the Internet)