Variations and anomalies of the external ear are quite frequent and range from slight asymmetries to serious deformities or even complete lack of development of the external ear. The incidence of external ear malformations is between 1:6,000 and 1:6,830 newborns. Severe malformations can be expected in a ratio of 1:10,000 to 1:20,000 newborns, severe malformations or aplasia in 1:17,500 newborns. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay The cause of ear malformations can be genetic or acquired. Congenital malformations of the auricle are the product of a sequence of insults during the embryological development of the auricular cartilage. This is why knowledge of the embryology of the ear is fundamental to understanding the causes of the variations. Various common anomalies described in the literature include protruding ears, narrowed ears, microtia, anotia, auricular atresia, preauricular pits and cysts, as well as accessory auricular appendages. These abnormalities result in varying degrees of functional impairment and severity, which may or may not require surgical intervention. Some of these anomalies cause only cosmetic imperfections while others can affect the function and physiology of the external ear. Furthermore, these aberrations may be linked to other congenital syndromes, although they are usually found in isolation. Some examples of congenital syndromes associated with ear malformations include craniofacial dysostosis (e.g. Crouzon syndrome), otofacial dysostosis (e.g. Treacher-Collins syndrome, Goldenhar syndrome) otocervical dysostosis (e.g. Klippel-Feil syndrome, Wildervanck), otoskeletal dysostosis (e.g. van der Hoeve -de-Kleyn) and chromosomal syndromes such as trisomy 13 (Paetau syndrome), trisomy 18 (Edwards syndrome), trisomy 21 (Down syndrome) and 18q. Acquired ear malformations can originate from injuries that occur during pregnancy or throughout a person's life. . Lesions during pregnancy can be due to infections (rubella, cytomegalovirus, herpes simplex virus), irradiation, chemical agents, malnutrition, Rh incompatibility, changes in atmospheric pressure, hypoxia as well as exposure to noise. Bleeding in the early part of pregnancy and metabolic disorders such as diabetes must be taken into consideration. Among the chemical agents that can cause ear malformations, drugs play a predominant role, a notable example is thalidomide, which in the early 1960s led to a notable increase in the frequency of malformations. Environmental agents such as herbicides, fungicides containing mercury and lead can also exert teratogenic effects on the external ear. Some of the most common causes of external ear malformations throughout a person's life include sports-related malformations such as cauliflower ear which is common among wrestlers, split earlobes due to large or heavy earrings, and traumatic ear deformities ear resulting from injury. Furthermore, the cause of various anatomical variations and malformations remains unknown due to the inability of thousands of patients to undergo genetic analysis and inadequate knowledge about the genetics of many of these variations. Furthermore, the clinical data and history relating to the exogenous influences of the patients involved may not be entirely clear and therefore it is not possible to identify a certain cause. Ultimately, regardless of etiology, variations in the anatomy of the external ear can result in the orientation, position, and size of the pinna..