Sphenopalatine Ganglion Block in Bimaxillary Orthognathic Surgery

"To perform an SPG block, the ultrasound linear probe is placed parallel to the zygomatic bone, facing anteriorly, to obtain an image that includes the ramus of the maxilla and mandible and the pterygoid process of the sphenoid bone.~A 23-gauge, 50 mm needle is inserted just behind the posterior orbital rim and advanced in an antero-caudal direction over the zygomatic arch. When the needle reaches the pterygopalatine fossa at approximately 5 cm, aspiration is performed to check for blood. If no blood is seen, 4 mL of 0.5% bupivacaine is injected.~The procedure is performed on both sides"

"To perform a Sham block, the ultrasound linear probe is placed parallel to the zygomatic bone, facing anteriorly, to obtain an image that includes the ramus of the maxilla and mandible and the pterygoid process of the sphenoid bone.~A 23-gauge, 50 mm needle is inserted just behind the posterior orbital rim and advanced in an antero-caudal direction over the zygomatic arch. When the needle reaches the pterygopalatine fossa at approximately 5 cm, aspiration is performed to check for blood. If no blood is seen, 4 mL of %0,9 NaCl is injected.~The procedure is performed on both sides."