title: Oral health condition in southern Chinese after radiotherapy for nasopharyngeal carcinoma: extent and nature of the problem.
abstract: OBJECTIVE
  To measure the oral health status of southern Chinese nasopharyngeal carcinoma (NPC) survivors 1-4 years after radiotherapy.
  
  
  METHODS
  A total of 109 subjects participated in this cross-sectional study. Thirty-eight subjects were NPC survivors, 40 subjects were patients newly diagnosed with NPC and 31 were healthy subjects. Verified clinical examination techniques were used to assess limitation of jaw opening, the presence of mucositis, candidiasis, dental caries, periodontal disease [community periodontal index (CPI)] including attachment loss (ALoss) and prosthetic status/need. Differences among three groups were tested by chi-squared and Kruskal-Wallis tests. Relationships between selected clinical variables and radiation parameters were analysed using Spearman's rank correlation coefficients.
  
  
  RESULTS
  The NPC survivors attended for dental treatment more frequently than the other groups (P < 0.01). NPC survivors had significant xerostomia (92%, P < 0.01), trismus (29%, P < 0.01), a higher prevalence of clinical candidiasis (24%, P < 0.01), a greater DMFT (16.4 +/- 7.0, P < 0.01), more decay/filled roots (2.1 +/- 2.9, P = 0.01) compared with new NPC patients and controls. No difference was found in CPI, ALoss, prosthetic status and need between groups. Dry mouth and tooth hypersensitivity were the most common oral problems perceived by the NPC survivors.
  
  
  CONCLUSIONS
  Despite having regular dental follow-ups, oral health was compromised in NPC survivors 1-4 years postradiotherapy.
authors.affiliation: Oral Rehabilitation, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR. ehnpow@hkusua.hku.hk
authors.forename: E H N
authors.initials: EH
authors.lastname: Pow
authors.forename: A S
authors.initials: AS
authors.lastname: McMillan
authors.forename: W K
authors.initials: WK
authors.lastname: Leung
authors.forename: D L W
authors.initials: DL
authors.lastname: Kwong
authors.forename: M C M
authors.initials: MC
authors.lastname: Wong
mesh_terms: D002180:Candidiasis, Oral / Q000145:classification; D002277:Carcinoma / Q000532:radiotherapy*; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D004245:DMF Index; D003731:Dental Caries / Q000145:classification; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009059:Mouth Diseases / Q000145:classification*; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D017622:Periodontal Attachment Loss / Q000145:classification; D010510:Periodontal Diseases / Q000145:classification; D010512:Periodontal Index; D017213:Root Caries / Q000145:classification; D018709:Statistics, Nonparametric; D014076:Tooth Diseases / Q000145:classification*; D014313:Trismus / Q000145:classification; D014987:Xerostomia / Q000145:classification