This depends on the age of the patient and how big the open bite is:
For adult patients with moderate open bite “2-3 mm”, it will take between 18-24 months
For growing patients with moderate open bite “ 2-3 mm”, it will take between 12-18 months
If the open bite is more than 4 mm or the use of mini-implants is needed; 24-28 months and more.