Classification of congenital anomalies of the ear and associated deformities

Abstract

Every patient presenting with congenital anomalies of the ear may present with one, two, three, or several other abnormalities nearby or in other organs and regions along the body. The auricle is at the center of the anomalies that involve neighboring structures. The congenital deformities of the ear involving cartilage reduction or its complete absence are classified as anotia, agenesis of the ear, and microtia. Among microtia there are two groups of deformities: Severe microtia and Moderate microtia. The group of moderate microtia presents two groups: moderate eutopic microtia and moderate ectopic microtia. My classification is the result of embryological, clinical, anatomical, functional, and surgical fundaments. It is an embryological fundament because the external ear is developed from the ectoderm. The middle and inner ear are developed from mesoderm. Therefore every patient classified with anotia, agenesis of the auricle, and moderate ectopic microtia always present congenital defects on other organs and regions caused by combined undevelopment of ectoderm and mesoderm. For these reasons patients in those groups present with anomalies of the external ear associated with complex deformities on neighboring regions and on internal organs of the chest and abdominal cavity, on the thoracic wall, on column, and lower and upper extremities. However, patients with severe microtia and moderate eutopic microtia present with only minor anomalies on neighboring regions without deformities on other organs because of undevelopment of the ectoderm. The clinical, anatomical, functional, and surgical fundaments are important aspects to evaluate the deformities and to choose the adequate technique for reconstruction.