title: Auto-fluorescence spectra of oral submucous fibrosis.
abstract: BACKGROUND
  Oral submucous fibrosis (OSF) is a chronic oral mucosal disease characterized by progressive deposition of collagen in the subepithelial connective tissue and epithelial atrophy. Previous studies have shown that at 330-nm excitation, the 380- and 460-nm emission peaks of the auto-fluorescence spectra for oral mucosal tissues reflect the collagen content in the subepithelial connective tissue and the nicotinamide adenine dinucleotide phosphate (NADH) content in the epithelial cells, respectively. Therefore, at 330-nm excitation OSF mucosa may have a higher 380-nm emission peak and a lower 460-nm emission peak than the normal oral mucosa (NOM).
  
  
  METHODS
  To test the above hypothesis, we measured the in vivo auto-fluorescence spectra of 59 OSF mucosal sites and compared the measured spectra with auto-fluorescence spectra obtained from 15 NOM samples from 15 healthy volunteers, five samples of friction hyperkeratosis (histologic diagnosis, hyperkeratosis and acanthosis) on OSF buccal mucosa (FHOSF), and 29 samples of oral leukoplakia (histologic diagnosis, hyperkeratosis and acanthosis) on OSF buccal mucosa (OLOSF).
  
  
  RESULTS
  We found that the spectrum of the OSF mucosa had a significantly higher 380-nm emission peak and a significantly lower 460-nm emission peak than the spectra of NOM, FHOSF, and OLOSF samples. When the mean (+/-SD) fluorescence intensities at 380 +/- 15 nm (I380 +/- 15 nm) and 460 +/- 15 nm (I460 +/- 15 nm) emission peaks and the mean ratio of I460 +/- 15 nm/I380 +/- 15 nm were compared between groups, we found that OSF group had a significantly higher mean value of I380 +/- 15 nm, a significantly lower mean value of I460 +/- 15 nm, and a significantly lower mean ratio of I460 +/- 15 nm/I380 +/- 15 nm than the NOM, FHOSF, and OLOSF groups (P < 0.001). However, no significant differences in the mean values of I380 +/- 15 nm, I460 +/- 15 nm, and ratio of I460 +/- 15 nm/I380 +/- 15 nm were found between NOM and FHOSF or OLOSF samples as well as between FHOSF and OLOSF samples (P > 0.05).
  
  
  CONCLUSIONS
  Because OSF mucosa has a very unique pattern of auto-fluorescence spectrum, we conclude that auto-fluorescence spectroscopy is a good method for real-time diagnosis of OSF.
authors.affiliation: School of Dentistry, College of Medicine, Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Hsin-Ming
authors.initials: HM
authors.lastname: Chen
authors.forename: Chih-Yu
authors.initials: CY
authors.lastname: Wang
authors.forename: Chin-Tin
authors.initials: CT
authors.lastname: Chen
authors.forename: Hsiang
authors.initials: H
authors.lastname: Yang
authors.forename: Ying-Shiung
authors.initials: YS
authors.lastname: Kuo
authors.forename: Wan-Hong
authors.initials: WH
authors.lastname: Lan
authors.forename: Mark Yen-Ping
authors.initials: MY
authors.lastname: Kuo
authors.forename: Chun-Pin
authors.initials: CP
authors.lastname: Chiang
mesh_terms: D000293:Adolescent; D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects; D001114:Areca / Q000009:adverse effects; D005453:Fluorescence; D006801:Humans; D008875:Middle Aged; D009061:Mouth Mucosa / Q000737:chemistry; D009914:Oral Submucous Fibrosis / Q000175:diagnosis* / Q000209:etiology; D012907:Smoking / Q000009:adverse effects; D013050:Spectrometry, Fluorescence; D018709:Statistics, Nonparametric