In antomy of middle ear i've read , peri sinus cells areound the sinus plate .what does sinus plate mean here ? .

Details, Details: In general, think of a plate as something relatively wide & thin like a dinner plate or the flat part of dentures (the dental plate), etc. So a sinus plate is a thin layer of bone that will separate one area from another, like the medial wall of the ethmoid sinus from the nasal area or the small thin-lined sinus air cells from the larger thin sinus plate that surrounds them to define that sinus.