Introduction: The extraction of premolars as a practical form of orthodontic therapy has been accepted for many years. but there remains a controversy regarding the effect of premolar extraction to improve esthetics as well as dentoskeletal relationship. The esthetic impact of the soft-tissue profile might play a major role in deciding on premolar extraction or non-extraction treatmen... https://www.roneverhart.com/RME-Fireface-UFX-III-Audio-Interface-p32300/