 The Oral Health Impact Profile OHIP-20 questionnaire will be used to assess oral health-related quality of life. This 20-item questionnaire measures self-reported impairment in edentulous populations within seven domains: functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability and handicap. The items will be rated on six-point Likert scales never 1, rarely 2, occasionally 3, often 4, very often 5 or all of the time 6. OHIP-20s total range is therefore 20-120 points, lower scores indicating better oral health-related quality of life 4, 18, 19. 