Changes in bone blood flow in segmental LeFort I osteotomies

Objective The aim of the present study was to investigate the effect of segmentation and different movements of the segments in LeFort I osteotomies on the bone blood flow (BBF). Material and methods The study sample of the prospective cohort study was composed of subjects scheduled to undergo 3-piece LeFort I osteotomies and simultaneous BSSO for correction of developmental skeletal deformities. The primary predictor variables were: time (T1, before LeFort I osteotomy; T2, after LeFort I osteotomy; T3, after segmentation and fixation of the maxilla) and magnitude of maxillary movement in the sagittal, vertical, and transverse planes measured in millimeters (mm). The subjects were assigned to 2 risk groups (high/low) depending on the amount of the movement. The primary outcome variable was maxillary bone blood flow measured with a laser Doppler at 4 sites: premaxilla, right and left maxillary lateral segments, and the mandible. Results No significant difference was observed among the 3 maxillary regions. The mean decrease of the maxillary BBF between T1 and T2 as well as the reduction of BBF between T2 and T3 were statistically significant for all regions ( P = .028 to P = .005 for T1/T2; P = .003 to P = .028 for T2/T3). No significant difference could be found between the 2 risk groups of maxillary movements. Conclusions Multisegmental maxillary osteotomies lead to a significant reduction of BBF. Moderate maxillary movements have no significant influence on the blood supply.