Question

why the space in maxillary or upper arch close faster than mandible or lower arch

Answer 1

contains about 2.5 mm of what is called leeway space, while in the maxillary arch, about 1.5 mm is available on the average. When the second primary molars are lost, the first permanent molars move forward (mesially) relatively rapidly, using the leeway space.

Answer 2

Answer:

please elaborate the question