[Analysis on characters of 220 cases of tympani membrane perforated]

220 cases of tympani membrane perforated were summarized retrospectively. The tympani membrane perforated of injury was different from otitis media's because they had marked or extreme marked difference in sex, age, ear distinction, shape, position, size, degree of hearing damaged, time of healing, cause of perforating and adhesive substance. This difference was relative to mechanism of tympani membrane perforated. The distinction gist of two sorts of tympani membrane perforated was expounded through comparison and analysis. It would be of great value to clinical forensic medical examination.