The effect of local anesthesia with vasoconstrictor on gingival blood flow during Le Fort I osteotomy

Purpose: In earlier studies, it has been documented that maxillary gingival blood flow (GBF) decreased significantly during the intraoperative course of a Le Fort I osteotomy. It was not clear, however, whether the observed decrease in GBF was caused by the osteotomy or by the use of local anesthetic with vasoconstrictor (LA + V). The purpose of this study was to measure the effect of LA + V on GBF during Le Fort I osteotomy using laser Doppler flowmetry (LDF). Patients and Methods: Using a randomized clinical trial study design, patients undergoing Le Fort I osteotomy were assigned to either a treatment (group 1, LA + V used) or a control group (group 2, LA + V not used). The predictor variable was group assignment (LV + V used or not used). The outcome variable was mean maxillary GBF. Maxillary GBF was recorded at predetermined times during the operation. Other study variables included age, sex, single- or double-jaw surgery, estimated blood loss, direction and magnitude of maxillary movements, temperature, pulse, mean blood pressure, O-2 saturation, and duration of operation. Results: There were 19 patients in group 1 (LA + V used) and 15 patients in group 2 (LA + V not used). In both groups, mean maxillary GBF decreased significantly during the operation (group 1, 33.3 +/- 13.1 to 16.9 +/- 16.1 mL/min/100 g tissue, P =.015; and group 2, 48.2 +/- 17.1 to 15.5 +/- 7.6 mL/min/ 100 g tissue, P =.001). The decrease in GBF occurred much earlier in group 1. By an average of 2.3 hours into the operation, the mean GBF was equivalent in both study groups (group 1, 10.6 +/- 8.6, and group 2, 13.1 +/- 9.4 mL/min/100 g tissue, P =.44). Conclusions: The results of this study confirm earlier findings that mean maxillary GBF decreases significantly during the intraoperative course of a Le Fort I osteotomy. In addition, LA + V significantly affects GBF during the early phase of the operation. Its effect, however, dissipates between the time of soft tissue dissection and maxillary downfracture.