Correlations Among Clinical Phenotypes, Radiological Examination Indexes, and Hearing Status in Congenital Microtia.

Microtia is a congenital malformation of the external ear that often presents with other anatomical abnormalities and ipsilateral hearing loss (HL). The aim of this study was to present the correlation among important phenotypic abnormalities in microtia and their relationship with HL in a clinical population in China. In this study, a retrospective analysis was conducted on 307 patients diagnosed with microtia who visited the Department of Auricular Reconstruction of the Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, for surgical auricle reconstruction from April 2021 to April 2022. Standardized classification of ear malformations, craniofacial CT scans, and pure tone audiometric data were collected, and statistical analyses were performed using the rank sum test, Kruskal-Wallis test, and Spearman's rank correlation coefficient. The results showed that group differences between ear malformation and variations in the development of mandible, external auditory canal (EAC), and mastoid pneumatization were statistically significant and each had a positive correlation. Among them, the correlation between development of ear and EAC was the most significant (Ρ=0.72). Besides, the severity of HL (97% were conductive) was positively correlated with ear and EAC dysplasia with or without mandibular hypoplasia. Based on the statistical analysis of the correlation between ear malformation and HL, the authors strongly recommend that facial phenotype reconstruction and hearing improvement of microtia should be considered comprehensively, regardless of whether children with microtia show HL or not, early diagnosis of audiology evaluation and appropriate intervention measures should be implemented.

Structure and Mechanical Performance of Biomimetic Costal Cartilage Models for Ear Framework Handcrafting Simulation.

SUMMARY: Ear framework handcrafting simulation using costal cartilage models is crucially important for ear reconstruction surgery education. Fabrication of proper models that are mechanically and structurally comparable to their native counterparts is an unmet challenge. The authors developed structure and mechanical performance biomimetic costal cartilage models for practicing and simulating handcrafting of ear frameworks. High-tensile silicone and three-dimensional techniques were used to fabricate biomimetic models. The models well-replicated the three-dimensional structure of human costal cartilage. Comprehensive mechanical tests showed that high-tensile silicone models had stiffness, hardness, and suture retention ability similar to those of their native counterparts, and they were distinctly superior to commonly used materials for costal cartilage simulation. This model satisfied surgeons and contributed to creation of outstanding ear frameworks. The recreated models were used in ear framework handcrafting workshops. Novices' surgical simulation performance with different models was compared and analyzed. People who used high-tensile silicone models have greater progress and confidence after training. Using high-tensile silicone costal cartilage models is an excellent choice for practicing and simulating the fabrication of ear frameworks manually. The models benefit practitioners and students in practicing handcrafting ear frameworks and surgical skills.