Tympanomastoid surgery is needed for the chronic draining ear or in the case of a cholesteatoma. This surgery involves the middle ear space as well as the mastoid and usually the incision may be through the tympanic membrane (eardrum) or behind the ear. 1 = Mastoid Bone 2 = Middle Ear 3 = Tympanic membrane (eardrum).his surgery involves the middle ear space as well as the mastoid and usually the incision may be through the tympanic membrane (eardrum) or behind the ear. 1 = Mastoid Bone 2 = Middle Ear 3 = Tympanic membrane (eardrum).
After WW1, they built the Maginot Line, along their border with Germany. This was a massive defensive fortifiations with underground bunkers that could be used for troops and support and command and control. In 1940, the Germans defeated this defensive line by attacking through Belgium and going around it.
Summary. At Munich in 1938, Chamberlain had appeased Hitler by giving him the Sudetenland areas of Czechoslovakia, but in March 1939, Chamberlain promised to defend Poland if the Nazis invaded. The main reason for this was because on 15 March 1939, Hitler had invaded Czechoslovakia a non-German country.