[1] Kings Coll London, Dent Inst Guys, London, England
[2] St Thomas Hosp, Div Populat & Patient Hlth, London, England
[3] Queen Mary Univ London, Inst Dent, Barts & London Sch Med & Dent, London, England
[4] Queen Mary Univ London, Wolfson Inst Prevent Med, Barts & London Sch Med & Dent, London, England