Tympanic membrane perforations: a critical analysis of 1003 ears and proposal of a new classification based on pathogenesis.

Purpose: To present a large series ears with tympanic membrane perforations (TMP), to describe their characteristics, and to propose a new classification system based on the pathogenesis of TMP.

Methods: This cross-sectional study was conducted at a tertiary university hospital with 1003 ears (792 consecutive patients with TMP in at least 1 ear). Otoendoscopy and audiometry were performed. Perforation measurements and their locations were digitally assessed. TMP with no suggestive signs of previous retraction were classified as Group 1, and those with possible previous retraction were classified as Group 2. Signs of retraction previous to the TMP, symptom length, perforation size and location, status of the contralateral ear, and hearing status were compared.

Results: Group 1 comprised 63.5% of the included ears. Compared to Group 2, Group 1 presented a higher rate of central perforations (99% vs. 53%), a shorter duration of symptoms, smaller perforations (mean area: 18.5% vs. 41.4%), a higher rate of perforations in the anterior quadrants, better hearing levels (mean tritonal gap: 23.9 dB vs. 29.2 dB), and a lower rate of abnormal contralateral ears (28% vs. 66%).

Conclusion: The classification of TMP into two groups based on signs of previous retractions is feasible and indicates two different levels of disease severity. While the group without previous signs of retraction comprises ears with more limited disease, membranes with previous retraction seem to show more severe disease and, consequently, a less functional middle ear.