No! Many orthodontic problems can and should be addressed prior to the loss of the last of the baby teeth. The timing for tooth eruption can also vary significantly between people. Waiting for the eruption of all of the adult teeth can sometimes make the treatment required more complicated. In many cases, successful orthodontic treatment is timing critical as it involves manipulation of the jaw development for correction of bite problems.
Different problems require treatment at different ages and stages of physical and dental development. Your orthodontist is best qualified to advise you on the best timing for treatment. Remember, an early consultation does not necessarily mean early treatment but it will give you the peace of mind of knowing where you stand in terms of dental development.