It depends really
1st of all, your jaw must be wide? long? enogh to accomodate the
new tooth and not mess up the arrangement of the pre-existing
teeth.
2nd, the tooth must be growing correctly, ie straight Up for lower
jaw, or Down for upper Jaw
If not, especially if its growing sideways into the side of ur
pre-existing molars, damn chia lat... They call this impacted
wisdom teeth, and SHOULD be extracted.
In the case of impacted wisdom teeth, it will be surgically
removed, which means the dentist jabs you with anesthetics in the
gum, then cuts/saws the tooth into pieces to remove... dun worry,
only the anesthetic jabbing hurts... and also once it wears off
after about 2hrs... But thats why God created pain-killers!! damn
effective.