Angus C. Cameron, BDS (Hons) MDSc (Syd) FDSRCS(Eng) FRACDS FICD, Head, Department of Paediatric Dentistry & Orthodontics, Westmead Hospital, Sydney; Clinical Associate Professor and Head, Paediatric Dentistry, The University of Sydney; Visiting Senior Specialist, The Children’s Hospital at Westmead, Australia and Richard P. Widmer, MDSc,FRACDS, Paediatric Dentist, Head of Department & Senior Staff Specialist, Paediatric Dentistry; Assistant Professor, University of Sydney,The Children’s Hospital at Westmead, Sydney, Australia