When a child grows teeth, the incisors are found to be crooked. Clinically, there are several cases of crooked incisors: 1, when a child starts to grow incisors, they are found to be crooked, and with the growth and development, the crookedness is slowly relieved and grows right after 1-2 years, which is a normal physiological replacement; 2, the crookedness becomes more and more serious with the growth, often accompanied by other diseases, such as retention of milk teeth leading to abnormal position of permanent teeth replacement, resulting in crookedness; 3, there are ambiguous multiple teeth above the incisors, crowding the position of permanent teeth eruption, resulting in permanent teeth growing out crooked, and the teeth growing crooked are relatively complicated.