1. Cleft Palate Center, Department of Orthodontics, and in the Department of Speech and Hearing Disorders, the University of Heidelberg, Heidelberg, Germany.
2. Department of Orthodontics, University of Würzburg, Würzburg, Germany
3. Department of Speech and Hearing Disorders, the University of Heidelberg, Heidelberg, Germany.
4. Department of Medical Psychology, the University of Heidelberg, Heidelberg, Germany.
5. Department of Orthodontics, the University of Heidelberg, Heidelberg, Germany.