[1] Univ Sheffield, Sch Clin Dent, Unit Oral & Maxillofacial Pathol, Sheffield S10 2TA, S Yorkshire, England
[2] Royal Hallamshire Hosp, Dept Histopathol, Sheffield S10 2JF, S Yorkshire, England
[3] Sheffield & Barnsley Teaching Hosp Natl Hlth Serv, Dept Oral & Maxillofacial Surg, Sheffield, S Yorkshire, England