Background: In some cases, there is insufficient external auditory canal (EAC) skin to cover the reconstructed canal wall after canal wall down (CWD) mastoidectomy. Acellular dermal matrix (ADM) can help to repair the skin, mucosa and other epidermal tissue defects.Aims: To investigate the repair effect of xenogeneic ADM (xeno-ADM) for EAC skin defects.Material and Methods: We retrospectively analyzed 28 patients who underwent open mastoidectomy combined with canal wall reconstruction and mastoid obliteration in our hospital. The xeno-ADM was used to repair the EAC skin defect. The epithelialization time, dressing change times, complications and hearing improvement post-operation were summarized and analyzed.Results: Reasons for using xeno-ADM included: 11 (39.3%) cases suffered from extensive middle ear cholesteatoma, three (10.7%) cases suffered from advanced EAC cholesteatoma, eight (28.6%) cases to solve the cavity-related problems, and six (21.4%) patients had a narrow EAC. The postoperative epithelialization time was 5.8 ± 1.6 weeks, and the number of dressing changes was 4.8 ± 1.6 times. There was no xeno-ADM rejection and related complications, the postoperative hearing improvement was statistically significant (p = .013).Conclusions and Significance: Xeno-ADM could be a safe, effective and simple method for repairing skin defect in the reconstruction of EAC after CWD mastoidectomy.

CONCLUSIONS: This study validates that a finite element model of the human ossicular chain and tympanic membrane can be used as an effective surgical assessment tool in clinics.
OBJECTIVE: The present study was performed to investigate the application of a finite element model of ossicular chain and tympanic membrane for fabrication of individualized artificial ossicles.
METHODS: Twenty patients (20 ears) who underwent surgery for middle ear disease (n = 20) and 10 healthy controls (10 ears) were enrolled in the hospital. Computed tomography (CT) and pure tone audiometry were performed before and after surgery. A finite element model was developed using CT scans, and correlation analysis was conducted between stapes displacement and surgical methods. An audiometric test was also performed for 14 patients before and after surgery.
RESULTS: Stapes displacement in the healthy group (average = 3.31 × 10-5 mm) was significantly greater than that in the impaired group (average = 1.41 × 10-6 mm) prior to surgery. After surgery, the average displacement in the impaired group was 2.55 × 10-6 mm, which represented a significant improvement. For the patients who underwent the audiometric test, 10 improved hearing after surgery, and stapes displacement increased in nine of these 10 patients.