Vinay Naresh Mistry1, Mohamed Imran Suida2, Deborah Kirkham3, Michael Wing Sung Ho2,4. 1. Oral and facial specialties, Mid Yorkshire Hospitals NHS Trust, Pinderfields Hospital, Wakefield, UK vins_mistry@hotmail.com. 2. Oral and facial specialties, Mid Yorkshire Hospitals NHS Trust, Pinderfields Hospital, Wakefield, UK. 3. The Northern Sexual Health, Contraception and HIV Service, Central Manchester University Hospitals NHS Foundation Trust, The Hathersage Centre, Manchester, UK. 4. Oral and Maxillofacial Surgery, Leeds Teaching Hospitals NHS Trust, Leeds Dental Institute, Leeds, UK.