The study of orthodontia is indissolubly connected with that of art as related to the human face. The mouth is a most impotent factor in making or marring the beauty and character of the face, and the form and beauty of the mouth largely depend on the occlusal relations of the teeth.

Our duties as orthodontists force upon us great responsibilities, and there is nothing which the student of orthodontia should be more keenly interested that in art generally, and especially in its relation to the human face, for each of his efforts, whether he realises it or not, makes for beauty or ugliness; for harmony or inharmony; for perfection or deformity of the face. Hence it should be one of his life studies.

Edward Angle (1907)