[1] Aintree Univ Hosp NHS Fdn Trust, Reg Maxillofacial Unit, Liverpool L9 7AL, Merseyside, England
[2] Univ Liverpool, Sch Canc Studies, Liverpool L69 3BX, Merseyside, England
[3] NHS Fdn Trust, Univ Hosp Aintree, Dept Oral Pathol, Liverpool L9 7AL, Merseyside, England
[4] Univ Liverpool, Dent Hosp, Dept Oral Med, Liverpool L69 3BX, Merseyside, England
[5] Edge Hill Univ, Fac Hlth, Evidence Based Practice Res Ctr EPRC, Ormskirk, Lancs, England