Clinical classification of non-syndrome congenital ossicular chain malformations

BACKGROUND: The existing classifications of congenital ossicular chain usually take the motility of the stapes footplate for differentiation, with a lack of attention on the concurrent malformations of facial nerve. OBJECTIVES: To explore the distribution of different types of congenital ossicular chain malformations and to propose a new classification for the guidance of clinical treatment. MATERIAL AND METHODS: Preoperative examinations and intraoperative findings of patients with congenital ossicular chain malformations from 2014 to 2025 were retrospectively collected. Based on the traditional Teunissen and Yang classification, a new classification was further proposed according to the key anatomical structures concerned in clinical diagnosis and treatment. RESULTS: A total of 119 patients with ossicular chain malformations were included in this study, 135 ears in total. The classification of patients in this study based on this new classification was as follows: 19 ears (14.1%) of type Ia, 60 ears (44.4%) of type Ib, 7 ears (5.2%) of type IIa, 33 ears (24.4%) of type IIb, 11 ears (8.1%) of type IIIa, and 5 ears (3.7%) of type IIIb. CONCLUSIONS AND SIGNIFICANCE: Based on a large cohort study, this innovative classification that centering on abnormal stapes and facial nerve contributes much to clinical diagnosis and treatment of non-syndrome congenital ossicular chain malformations.