title: Assessment of local hemodynamics in periodontal inflammation using optical spectroscopy.
abstract: BACKGROUND
  Among the newly emerging diagnostic approaches for periodontitis, optical spectroscopy is a promising complementary diagnostic tool. The objective of this study is to verify the reproducibility of this method at a geographically distinct location (Suzhou, China) to a broader patient population using similar instrumentation to that in a previous report.
  
  
  METHODS
  Using a portable optical near-infrared spectrometer, optical spectra were obtained, processed, and evaluated from healthy (n = 62), gingivitis (n = 98), and periodontitis (n = 47) sites from a total of 51 patients. A modified Beer-Lambert unmixing model that incorporates a non-parametric scattering loss function was used to determine the relative contribution of oxyhemoglobin and deoxyhemoglobin to the overall spectrum. The balance between tissue oxygen delivery and oxygen use in periodontal tissues was then assessed.
  
  
  RESULTS
  Tissue oxygenation decreased significantly from healthy sites to sites with gingivitis (P <0.01) and between gingivitis and periodontitis (P = 0.015). This is largely caused by a significant increase in deoxyhemoglobin between normal and gingivitis (P <0.01) and a concomitant decrease in oxyhemoglobin between gingivitis and periodontitis (P = 0.02).
  
  
  CONCLUSIONS
  This study supports previous findings that tissue oxygenation as measured by optical spectroscopy is significantly decreased in periodontitis and that optical spectroscopy can simultaneously determine multiple inflammatory indices related to periodontal disease directly in gingival tissues in vivo.
authors.affiliation: Department of Stomatology, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Zili
authors.initials: Z
authors.lastname: Ge
authors.forename: Kan-Zhi
authors.initials: KZ
authors.lastname: Liu
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Xiang
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Hui
authors.forename: Elicia
authors.initials: E
authors.lastname: Kohlenberg
authors.forename: Michael G
authors.initials: MG
authors.lastname: Sowa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D005881:Gingiva / Q000098:blood supply / Q000378:metabolism*; D005891:Gingivitis / Q000175:diagnosis* / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D010108:Oxyhemoglobins / Q000378:metabolism; D010518:Periodontitis / Q000175:diagnosis* / Q000378:metabolism; D012016:Reference Values; D012039:Regional Blood Flow; D019265:Spectroscopy, Near-Infrared; D055815:Young Adult
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin