Some people worry that although their teeth look good now but will they get worse?
The answer to this can only be based on long term clinical studies and these show that in general your upper teeth remain fairly stable but your lower teeth do crowd slowly as you get older.
Why do they crowd is still uncertain but in about 10% of cases the lower erupting wisdom teeth are thought to be responsible, the remaining cases are thought to be due to a process called late stage growth this occurs between 21 to 28 as is mainly vertical growth of the face. this causes the lower incisors to lean back slightly as they lean back they begin to crowd.
The important point here is that this crowding will happen whether you have orthodontic treatment or not – all that happens is that you begin with a better starting point after treatment i.e. with straight teeth, however if you wear your retainers long term you will resist the growth effects on your teeth and your teeth will remain straight.
How long is long term retention, this unfortunately means forever on a nightly basis certainly between the ages of 20 to 30, because your face is continually growing - although very slowly in a vertical direction