Sphenopalatine ganglion (SPG) block is used for a variety of craniofacial pain syndromes either through the trans-nasal route or via the infrazygomatic approach. Intraoperative imaging can identify the pterygopalatine fossa (PPF) but not the exact position of the SPG. Accurate localization of the PG requires knowledge of the relevant anatomical landmarks.

Thirty mid sagittal head and neck cadaveric sections were studied and the morphometric data was te correct SPG localization via trans-nasal roach and infrazygomatic approach.

The sphenopalatine foramen (SPF) was located at an average distance of 55 mm from the anterior nasal spine at a mean angle of 22°. It was at or just superior to the midpoint of a line joining the skull base and the hard palate. The SPG was located 4 mm posterior and 4.7 mm lateral to the SPF at a mean distance of 6.3 mm from the SPF at an inclination of about 50° in both the sagittal and coronal planes. In the infrazygomatic approach, the SPG was between 4.5 and 6.3 cm the skin and an angle of about 7° posterior and inferior.

These morphometric measurements will be of help to the clinician for accurate electrode or needle placement for SPG block and in avoiding complications related to inaccurate needle placement.

Gupta T, Aggarwal A, Sahni D. Anatomic Landmarks and Morphometric Measurements for Accurate Localization of the Sphenopalatine Ganglion via the Transnasal and Infrazygomatic Approaches: A Cadaveric Study. J Postgrad Med Edu Res 2014;48(1):14-18.