İrregularly aligned or and congested teeth, intermaxillary pasition problems of jaws relating to each other are the indication of orthodontic treatment. And also; difficulty in chewing, non nasal breathing pressing the tongue against the anterior teeth, finger sucking habit, may also require orthodontic treatment.
Often the necessity of orthodontic treatment may not be easily understood.  The best approach is to take your child to a dental clinic regularly (every 6 months) from an early age. In this way, your dentist can refer you to the orthodontist (the dentist who treats dental irregularities) before it is too late. With early intervention, many problems can be prevented before proceeding.