Teacher:Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.
Teacher: Now, understand the problem? Solve this instance: Abstract: A modification of Patterson's external antro-ethmoidectomy operation is described which provides a more direct and simpler approach than the transantral operation for decompression of the orbit.
Student:
Ethmoid Bone