Garry qualified as a dentist in 1990 having attained a Bachelor of Dental Surgery at the University of Liverpool. Garry then held resident maxillofacial Senior House Surgeon appointments for two and a half years at The Bristol Dental Hospital and Bristol Royal Infirmary, Bristol and The Royal Devon and Exeter Hospital, Exeter. Garry was then appointed Senior House Surgeon in Children's Dentistry and Orthodontics at The Manchester Dental hospital. Between 1993 and 1994 Garry practised as General Dental Practitioner in St Helens, Merseyside and in 1994 was appointed Registrar in Orthodontics at the Eastman Dental Hospital and Institute, London where he spent three years gaining orthodontic postgraduate training.
Garry obtained the Fellowship in Dental Surgery from the Royal College of Surgeons of England in 1993, a Masters Degree from the University of London in 1996 and the Membership in Orthodontics of the Royal College of Surgeons of England in 1997.