Change of mastoid operation in tympanoplasty during last twelve years was reviewed. The tympanoplasty without mastoidectomy or with mastoidectomy of limited extent had been enthusiastically accepted because of easy postoperative care and satisfactory hearing result. About a decade of experience was needed to establish that such tympanoplasty should not be applied to the ear having cholesteatoma or active infection. Recurrence of disease, particularly cholesteatoma, retraction or adhesion of the grafted membrane, and deterioration of the tissue utilized for reconstruction not infequently occurred for long postoperative period. In order to avoid these delayed failures and to preserve the important structures for hearing improvement, either single or staged tympanoplasty using intact canal wall technique has been recognized to be a reliable procedure. The value of tympanoplasty with radical mastoidectomy combined with mastoid obliteration has remained unchanged or even increased because of its enduring safety. The analysis of the findings in reoperation of 104 ears indicated that a more careful eradication of the disease was needed in the perilabyrinthine, perifacial, mastoid tip cells, tympanic sinus, and hypotympanic cell in order to achieve one of the objectives of tympanoplasty, elimination of the disease and restoration of the safe ear.
