title: Comparing clinical attachment level and pocket depth for predicting periodontal disease progression in healthy sites of patients with chronic periodontitis using multi-state Markov models.
abstract: OBJECTIVE
  To understand degeneration of healthy sites and identify factors associated with disease progression in patients with chronic periodontitis.
  
  
  METHODS
  Data on healthy sites from 163 American and Swedish subjects were analysed using two-three-state (health, gingivitis, chronic periodontitis) Markov models based on bleeding on probing (BOP), and either clinical attachment level (CAL) + BOP or pocket depth (PD) + BOP.
  
  
  RESULTS
  In 2 years, 10% (CAL + BOP) and 3% (PD + BOP) of healthy sites developed chronic periodontitis. On average, healthy sites remained healthy for 32 months before transiting in both models. Most transitions (87-97%) from health were to the gingivitis state. The expected duration of the gingivitis lesion was 4-5 months and sites recovered with a high probability (96-98%). Disease severity as measured by number of sites with CAL/PD > 4 mm at baseline and smoking, were associated with fast progression from health to chronic periodontitis within 6 months as were gingival redness in the PD + BOP model only. With age, the rate of disease progression to gingivitis decreased.
  
  
  CONCLUSIONS
  Transition probabilities for gingivitis and chronic periodontitis were higher with CAL + BOP than with PD + BOP. Smoking and disease severity were significant predictors for fast progression.
authors.affiliation: Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway.
authors.forename: Ibrahimu
authors.initials: I
authors.lastname: Mdala
authors.forename: Ingar
authors.initials: I
authors.lastname: Olsen
authors.forename: Anne D
authors.initials: AD
authors.lastname: Haffajee
authors.forename: Sigmund S
authors.initials: SS
authors.lastname: Socransky
authors.forename: Magne
authors.initials: M
authors.lastname: Thoresen
authors.forename: Birgitte Freiesleben
authors.initials: BF
authors.lastname: de Blasio
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D055113:Chronic Periodontitis / Q000145:classification / Q000503:physiopathology* / Q000628:therapy; D003131:Combined Modality Therapy; D018450:Disease Progression; D004198:Disease Susceptibility / Q000503:physiopathology; D005260:Female; D005544:Forecasting; D005891:Gingivitis / Q000503:physiopathology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000145:classification*; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification*; D011336:Probability; D012044:Regression Analysis; D012907:Smoking
keywords: antibiotics; chronic periodontitis; multi-state Markov models; periodontal therapy