The anatomy of the middle ear cleft is extremely important in combined approach tympanoplasty. It relies on an accurate knowledge of the relationship between the facial nerve in its vertical portion and the chorda tympani. Indeed it is the bony triangle between them that is drilled in order to open up the channel between the mesotympanum and mastoid regions. It is referred to as the posterior Tympanoplasty Surgery. In all other respects the anatomy of the middle ear cleft is as for any other operation.