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Computerized planimetric method for clinical plaque measurement
Author(s) -
Söder PerÖsten,
Jin Li Jian,
Söder Birgitta
Publication year - 1993
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.1993.tb01640.x
Subject(s) - dental plaque , dentistry , orthodontics , computer science , medicine
A computerized planimetric method for plaque area measurement has been developed. Using a computerized image analysis system (CIAS), the plaque area and tooth area on color slides were digitized and the number of pixels automatically counted. The proposed Plaque Percent Index (P% Index) expresses plaque area as a percentage of tooth area. The reproducibility of this method was tested and the influence of photographic technique on the P% Index was determined. The association of the Turesky modified Quigley‐Hein plaque index (Q‐H Index) and the P% Index was assessed. The present method was highly reproducible for the P% Index with an intraexaminer variation of 0.28% and intraexaminer correlation coefficient of 0.99. The results show that highly reproducible P% Index values with an error of less than 3.0% were obtained when the photographs were taken under the following conditions. For the buccal surfaces of anterior teeth, the slides were photographed within a 20‐degree range in the horizontal plane and a 30‐degree range in the vertical plane; and for the lingual/palatal surfaces of anterior teeth and the buccal or lingual/palatal surfaces of posterior teeth, the slides were photographed with an image of the whole tooth surfaces in the photographic mirrors. The comparison of the Q‐H Index and the P% Index revealed that for each score of the Q‐H Index the corresponding values of P% Index were wide with a significant crossover value, although a strongly positive correlation was found between the Q‐H Index and the P% Index (r = 0.92, P <0.01). This study indicates that the proposed P% Index, quantitatively expressed on an interval scale, has high reproducibility and discriminative power.