He received training at many prominent institutions including Massachusetts General Hospital, Harvard University, the Children’s Hospital of Philadelphia, the University of Pennsylvania, and Vanderbilt Medical Center and University before moving to Toronto. He served as the Medical Director of the Craniofacial Program in Toronto from 1986 to 1992 and during that period, was incredibly prolific, publishing over 100 papers resulting from his work at the Hospital for Sick Children and established the institution as a centre of excellence and one of the top places to train. As the Medical Director of the Craniofacial Program, he established autonomy for the program as an entity separate from the Cleft Lip and Palate Program and initiated the Craniofacial Program registry in 1987 and since that time, over 4,000 patients with craniofacial disorders have been enrolled. He is the author of Orthognathic Surgery: Principles and Practice and Craniofacial and Maxillofacial Surgery: In Children and Young Adults, considered to be one of the best books detailing the sub-specialty of pediatric craniomaxillofacial surgery. He was recruited to Georgetown University Medical Center in 1992, and continues his private practice in the Washington D.C. area.
Jeff Posnick was appointed as the Medical Director of the Craniofacial Program at the Hospital for Sick Children in 1986 following the departure of Dr. Ian Munro. He was unique in having training in both dentistry (DMD from Harvard University) and medicine (MD from Vanderbilt University) and is board certified in both Oral-Maxillofacial Surgery and Plastic Surgery.