While performing external ethmoidectomy, anterior ethmoidal artery is located at frontoethmoidal suture line. Its distance from anterior lacrimal crest is:

Anterior ethmoidal artery is located approximately 24 mm posterior to anterior lacrimal crest along the frontoethmoidal suture. Posterior ethmoidal artery is situated further back, i.e. 12 mm from the anterior ethmoidal artery. Optic nerve is situated 6 mm still posterior to posterior ethmoidal artery.Relationship between anterior and posterior ethmoidal vessels and optic nerve.