Mark, is a Staff Specialist in Oral Medicine at Westmead Hospital, a role he has undertaken for over 25 years, with clinical appointments in the Westmead Centre for Oral Health, the Blood and Bone Marrow Transplant Unit, the Head and Neck Cancer Clinic and Oral Immunology Clinic. Mark is also in private specialist practice with the Skin Hospital, Darlinghurst. Mark is also the Head of the Oral Medicine Specialist Training Program of the University of Sydney, which he inaugurated, and has overseen the training (bar one) of all the current oral medicine specialists in New South Wales.