As Assistant Professor in Facial Plastic and Reconstructive Surgery at Philadelphias prestigious Thomas Jefferson University, Dr. Krein is considered to be an outstanding teacher and lecturer. He routinely gives lectures and teaches courses on many of the intricacies of facial plastic surgery to both medical students, residents and other physicians. His practice encompasses the entire spectrum of facial plastic and reconstructive surgery, including rhinoplasty, eyelid surgery, facial rejuvenation surgery, fat transfers, facial augmentation, wrinkle treatment, corrective surgery for facial defects, ear reshaping, microtia repair, microsurgery and reconstruction of cancer patients and extensive post-traumatic deformities. He also is considered to be one of the experts when it comes to Botox and injectable fillers (Restylane, Juvaderm, Radiesse, Sculptra).