title: Fractal dimensions of ductal patterns in the parotid glands of normal subjects and patients with Sjögren syndrome.
abstract: OBJECTIVE
  The sialographic ductal patterns of the parotid glands in patients with Sjögren syndrome were compared with those of normal patients by measuring the fractal dimensions.
  
  
  METHODS
  Fractal dimensions were estimated using the modified pixel dilation method.
  
  
  RESULTS
  The mean fractal dimension was 1.64 +/- 0.06 for the normal glands and 1.39 +/- 0.10 for the glands with Sjögren syndrome (P < .005). No correlation between the age or sex and fractal dimension was observed for both groups. In Sjögren syndrome, a significant difference in the fractal dimension was observed between the subgroup having punctuate fillings with a diameter less than 1 mm and the subgroup from 1 to 2 mm (P < .001).
  
  
  CONCLUSIONS
  The fractal dimension is useful as a numeric grading of the complexity of the ductal pattern and the progression of parotid disease.
authors.affiliation: Department of Dental Radiology and Radiation Research, Faculty of Dentistry, Tokyo Medical and Dental University, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Honda
authors.forename: M
authors.initials: M
authors.lastname: Domon
authors.forename: T
authors.initials: T
authors.lastname: Sasaki
authors.forename: N
authors.initials: N
authors.lastname: Obayashi
authors.forename: M
authors.initials: M
authors.lastname: Ida
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging*; D011859:Radiography; D012859:Sjogren's Syndrome / Q000000981:diagnostic imaging*