The dangerous type chronic otitis media occurs with pars flaccida and marginal perforations. 慢性中耳炎的危险型可出现鼓膜松弛部的穿孔和鼓膜边缘性穿孔。
Pars flaccida perforation were found in 4 cases with invasion of the cholesteatoma into the tympanic cavity, the ossicular chains were compressed or destroyed. 其中4例鼓膜松弛部穿孔,胆脂瘤侵入鼓室,听骨链受压、内移,或不同程度破坏。