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.
Fractal dimensions were estimated using the modified pixel dilation method.
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).
The fractal dimension is useful as a numeric grading of the complexity of the ductal pattern and the progression of parotid disease.