title: The effects of the number of natural teeth and posterior occluding pairs on the oral health-related quality of life in elderly dental patients.
abstract: OBJECTIVE
  To compare between the oral health-related quality of life (OHRQoL) of Thai elderly dental patients at the Faculty of Dentistry, Chulalongkorn University with at least 20 natural teeth (NT) and those with less than 20 NT, and between those with at least 4 posterior occluding pairs (POP) and those with less than 4 POP.
  
  
  BACKGROUND
  Thai government recommended that elderly people should have at least 20 NT and 4 POP.
  
  
  METHODS
  The participants comprised 240 Thai elderly dental patients who were interviewed and had their OHRQoL determined using the Oral Impacts on Daily Performances Index (OIDP). Higher OIDP score indicates poorer OHRQoL. We counted the functional NT and POP in each participant.
  
  
  RESULTS
  Participants with less than 20 NT or less than 4 POP had significantly higher OIDP scores than those with at least 20 NT or at least 4 POP. Moreover, when we evaluated one by one tooth loss, we found the first and the last significant differences between the OIDP scores in the participants with at least 23 teeth and with less than 23 teeth, and those in the participants with at least 5 teeth and with less than 5 teeth, in consequently.
  
  
  CONCLUSIONS
  Thai elderly participants with at least 20 NT or at least 4 POP had greater OHRQoL than those with less than 20 NT or less than 4 POP, and in our study sample, we observed that 5 teeth may be an important clinical threshold for Thai elderly dental patients' quality of life.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Kwanrutai
authors.initials: K
authors.lastname: Somsak
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Orapin
authors.initials: O
authors.lastname: Kaewplung
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D001294:Attitude to Health; D003430:Cross-Sectional Studies; D003729:Dental Care; D003830:Denture, Partial, Fixed / Q000523:psychology; D003832:Denture, Partial, Removable / Q000523:psychology; D004435:Eating / Q000502:physiology; D005260:Female; D006304:Health Status; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009066:Mouth, Edentulous / Q000453:epidemiology* / Q000523:psychology; D009909:Oral Health / Q000706:statistics & numerical data*; D009910:Oral Hygiene; D011788:Quality of Life; D012494:Sampling Studies; D012890:Sleep / Q000502:physiology; D012904:Smiling / Q000523:psychology; D013060:Speech / Q000502:physiology; D013785:Thailand / Q000453:epidemiology; D016388:Tooth Loss / Q000523:psychology
keywords: elderly dental patients; number of natural teeth; number of posterior occluding pairs; oral health-related quality of life.