Unusual orthodontic correction of bilateral maxillary canine-first premolar transposition. 
Tooth transposition is a subject that intrigues orthodontists because of the associated treatment planning.  Approximately 0.3-0.4% of the population has this type of tooth disharmony, and in the literature, most authors are in disagreement about the treatment approach.  In this article, a case is presented of bilaterally maxillary canine-first premolar transposition associated with bilaterally upper lateral incisor agenesis treated in a very unusual way.  The transposed teeth were orthodontically reversed to their normal sequence and the missing lateral incisor spaces closed.  We choose this approach because once the decision was made to close the upper lateral incisor agenesis spaces, it was inadequate to position the upper first premolars in contact with the central incisors.