The clinical course of chronic periodontitis: V. Predictive factors in periodontal disease.
BACKGROUND
The factors associated with initial periodontitis are not well understood and cannot be identified by cross-sectional studies.


OBJECTIVE
To identify the factors associated with the initiation of chronic periodontitis using ante-dependence modelling.


METHODS
A 26-year longitudinal study of the natural history of periodontitis served as the basis for the study. In 1969, 565 Norwegian men aged 16-34 years were surveyed. Subsequent surveys were performed in 1971, 1973, 1975, 1981, 1988 and finally in 1995, with 223 remaining subjects. Plaque (PlI), gingival (GI) and calculus indices (CI) and loss of attachment (LoA) were recorded. Ante-dependence modelling using a Markov chain enabled the results of this sequence of examinations to be analysed longitudinally, taking into account serial dependence, describing temporal changes in patients' levels of disease and allowing for both progression and regression between disease categories.


RESULTS
With age, the rate of disease regression decreased. Increasing calculus accumulation and smoking increased the rate of disease progression, while increasing GI increased the rate of regression.


CONCLUSIONS
Increased mean CI and smoking were significant predictive covariates for progression, while increased mean GI and younger age predicted regression of initial periodontitis.
Schätzle
Marc
M
Universitiy of Zurich, Zurich, Switzerland.
Faddy
Malcolm J
MJ
Cullinan
Mary P
MP
Seymour
Gregory J
GJ
Lang
Niklaus P
NP
Bürgin
Walter
W
Anerud
Age
A
Boysen
Hans
H
Löe
Harald
H
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D055113:Chronic Periodontitis / Q000503:physiopathology*; D015331:Cohort Studies; D003728:Dental Calculus / Q000145:classification; D003774:Dental Plaque Index; D018450:Disease Progression; D005544:Forecasting; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008390:Markov Chains; D008954:Models, Biological; D009911:Oral Hygiene Index; D017622:Periodontal Attachment Loss / Q000145:classification; D010512:Periodontal Index; D010518:Periodontitis / Q000503:physiopathology; D012307:Risk Factors; D012907:Smoking; D013997:Time Factors; D055815:Young Adult