In order to maintain your teeth in their proper position you will need to wear a form of a retainer for life. Our bodies are alive and are in constant movement and so are our teeth, they tend to move forward and inward as we get older.
If you have a fixed lingual retainer, this is enough to hold your teeth in place and a night time retainer is not required after the first year.
If you choose not to have a fixed lingual placed you will need to wear your retainer 12-22 hours a day for the first 2 months, then 12 hours a day for up to a year. Once the first year has passed, we recommend wearing your retainer 3-5 nights a week.