You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is All are true about Mastoid antrum except and explain in detail?
(B) It does not communicate with middle ear# Mastoid Antrum:> Is a large, air-containing space in the upper part of mastoid and communicates with the attic through the aditus.> Its roof is formed by the tegmen antri and is a continuation of the tegmen tympani and separates it from the middle cranial fossa.> The lateral wall of antrum is formed by a plate of bone which is on an average 1.5 cm thick in the adult.> It is marked externally on the surface of mastoid by suprameatal (MacEwen's) triangle.