<prompt> Lines of Sebileau pass throughFloor of orbit and maxillary antrumFloor of nasal cavity and maxillary antrumFloor of orbit and nasal cavityFloor of orbit and roof of mouth  <response>: Ledermans classification of carcinoma of the maxillary sinus is using two lines of Sebileau, one passing through the floor of maxillary antrum the other through the roof of antrum or floor of orbit dividing area into Supra structure, Mesostructure and Intra structure. Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 233 