title: Changes in CT cerebral blood flow and volume associated with rapid maxillary expansion in a rabbit model.
abstract: OBJECTIVE
  To evaluate hemodynamic changes of the brain under the high forces of a rapid maxillary expansion (RME) appliance in a rabbit model.
  
  
  METHODS
  Twenty-four male New Zealand white rabbits were selected (12 weeks old, mean weight 3.01 ± 0.22 kg). A modified acrylic resin bonded RME appliance was used for expansion. A series of perfusion computed tomography examinations was performed before expansion (T0), on the fifth day of expansion (T1), at the end of the expansion process (T2), and after 10 days of retention (T3). Cerebral blood flow, cerebral blood volume, and mean transit time maps were recorded and parametrics evaluated. Statistical analyses were performed with analysis of variance with post hoc tests.
  
  
  RESULTS
  Mean cerebral blood flow showed an increase from T0 to T2 and then a decrease from T2 to T3, but the change was not statistically significant. Mean cerebral blood volume and mean transit time increased significantly from T0 to T2, and all perfusion parameters increased from T0 to T3.
  
  
  CONCLUSIONS
  RME is a safe orthopedic method despite the high expansion force. Perfusion computed tomography is effective for evaluating the hemodynamic changes of the brain caused by some orthopedic therapies. The increase in both cerebral blood volume and cerebral blood flow may help to explain why RME could alleviate the symptoms of enuretic children.
authors: Institute of Stomatology, Nanjing Medical University, Department of Orthodontics, Affiliated Hospital of Stomatology, Nanjing, PR China.
authors: Qingyi
authors: Q
authors: Li
authors: Wei
authors: W
authors: Wang
authors: Qingbo
authors: Q
authors: Zhang
authors: Lin
authors: L
authors: Wang
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001810:Blood Volume; D001921:Brain / Q000098:blood supply*; D002560:Cerebrovascular Circulation; D003799:Dental Stress Analysis; D008297:Male; D010155:Palatal Expansion Technique / Q000295:instrumentation; D055420:Perfusion Imaging / Q000379:methods; D011817:Rabbits; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods