Depending on the age group and the type of closure, the time required for closure varies, as follows: 1) Teenagers and children’s teeth move faster, so the time required for closure is shorter, from the beginning of closure to the end of closure is generally about 1 year; 2) Adults need longer time for closure, because the movement of teeth and bone reconstruction will take some time, generally about 1.5 years It takes about 1.5 years to close the gap. For different types of gaps, the time required is also different. If a large tooth is missing, the successor tooth needs to be pulled into place to replace the missing large tooth, and the approximate time required to move each tooth is about 1 year. If the first big tooth is lost, the back big tooth can be moved forward to the normal position, so that the back big tooth can be pulled forward to fill the vacant space. However, since the roots of the big teeth are very large and long, it may take 1 year to move each big tooth, and 2 big teeth in a row, it will take about 2 years just to move the big teeth, and the whole orthodontic treatment may take about 4 years.