title: Mandibular bone changes in sickle cell anemia: fractal analysis.
abstract: OBJECTIVE
  The radiographic changes of mandibular bone texture was evaluated in patients with sickle cell anemia (SCA) and healthy controls. Fractal analysis was employed.
  
  
  METHODS
  Thirty-five individuals (age range 11 to 40 years) who had been diagnosed as having homozygous SCA were enrolled as the patient group. Twenty-six healthy individuals within the same age range constituted the controls. Panoramic radiographs of all subjects were obtained using analog film and then digitized. All procedures for calculation of the fractal dimension were performed using Image J version 1.34s software (National Institutes of Health, Bethesda, MD). ROIs were selected as 64 x 64 pixel-sized squares, which were located between the first molar and second premolar teeth of the right mandibular segment. The fractal dimension (FD) was calculated by using the box-counting function. FD values of SCA and control groups were analyzed statistically by using Student t tests; alpha was set at 0.05.
  
  
  RESULTS
  The FD values for SCA patients were different from those of the healthy controls (mean FD SCA = 1.6855; mean FD controls = 1.7196); with a significance of P = .050. FD values for the SCA group had higher standard deviations (SD) than was the case for the healthy controls (SCA SD = 0.0859, control SD = 0.0459). When individuals were subclassified according to their age being younger than 20 or 20 years and over, the mean FD values of patients under 20 years of age were significantly lower than both the SCA patients over 20 years of age and all of the healthy controls (P < .05).
  
  
  CONCLUSIONS
  SCA patients under age 20 years showed lower FD values than the controls and this finding pointed to scarcity of trabecular bone in this group.
authors.affiliation: Ege University School of Dentistry, Department of Restorative Dentistry, Izmir, Turkey.
authors.forename: Ayşegül Kaya
authors.initials: AK
authors.lastname: Demirbaş
authors.forename: Selin
authors.initials: S
authors.lastname: Ergün
authors.forename: Pelin
authors.initials: P
authors.lastname: Güneri
authors.forename: B Oğuz
authors.initials: BO
authors.lastname: Aktener
authors.forename: Hayal
authors.initials: H
authors.lastname: Boyacioğlu
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000473:pathology*; D015519:Bone Density; D016022:Case-Control Studies; D002648:Child; D005260:Female; D017709:Fractals; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008334:Mandible / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology*; D011862:Radiography, Panoramic