Please see MedicineNet site on orthodontic treatment for information on this subject. ... (12 Dec 1998) ... 
[n] - dental treatment that corrects irregularities of the teeth or of the relation of the teeth to surrounding anatomy
noun dental treatment that corrects irregularities of the teeth or of the relation of the teeth to surrounding anatomy; treatment is usually by braces or mechanical aids; `orthodontic treatment of facial abnormalities`