Deformities of the outer ear: causes, symptoms, diagnosis, treatment

Deformations of the outer ear include changes in the shape and size of the auricle and external auditory canal, which can be both congenital and acquired as a result of trauma or inflammatory-destructive diseases. Congenital defects of the outer ear mainly refer to developmental anomalies and are often combined with anomalies in the development of the auditory and vestibular apparatus, as well as with other abnormalities of the development of the skull, such as the mandibular dystostosis of Najera and Renier, craniofacial dysostosis of the Cruson, congenital paralysis of the facial musculature, etc. These changes , according to J. Portman, occur during the embryonic development of the gill arches.

There is also the view that these disorders can occur as a result of intrauterine infection (rubella in the mother) or trauma.

Defects in the development of the auricle. J.Robin (1923, 1929), a prominent French specialist in the field of congenital head and maxillofacial defects, divides all the defects in the development of the auricle into congenital and acquired ones - partial and complete, as well as anomalies in form, position and number. Acquired deformities of the auricle are determined by the type of injury or disease and are described above.

Congenital malformations of the auricle are divided into the following species.

• Protruding anuricle (one or both) at their normal size or when combined with a macro. The protrusion of the ear can be of two types: total and partial. In the first case, the deformation also concerns the entrance to the external auditory canal, which can be covered by the bottom of the ear cavity; in the second case, the bend of the auricle anteriorly can touch only the area of the curl, which is caused by the reduction of the scaphoid fossa.
• Macrotonia is characterized by a sharp increase in one or both of the auricles at their normal position.
• Microtia is characterized by a significant decrease in the size of the auricle, its atrophy, and a combination with defects in shape.
• Polyotia is characterized by the presence in the preco-caecal region of several skin formations containing inside the rudiments of cartilaginous tissue.
• Splitting of the lobe (coloboma) can be congenital or acquired (in women) as a result of perforation of the lobe, wearing heavy earrings.
• Giantism of the lobe is represented as a sharply increased lobe on one or both sides.
• Aging of the auricle is the total absence of an inoculum of an innate character.
• Dystopia of the auricle, often combined with the syndrome of Robin; is characterized by displacement of the urine downwards and posteriorly, combined with aplasia of the lower jaw.

Defects in the development of the external auditory canal.

Pathological anatomy. P.Robin divides all the defects in the development of the external auditory canal into congenital constrictions, membranous and bony atresia, as well as to defects in form. The membranous atresia is located on the border between the membranous cartilaginous and bony parts of the external auditory canal where an original full or partial diaphragm is preserved, covered on both sides with skin sheets, between which a thin layer of mesenchymal tissue is retained.

Bone congenital atresia are also complete and partial and are often combined with defects in the development of the structure of the tympanum.

Symptoms. Incomplete atresia of the external auditory canal is not manifested by any subjective signs, however, when the narrow hole is blocked by the products of the dermis's vital activity, there is a hearing impairment according to the type of sound production. Complete atresia are manifested by pronounced hearing loss on one or both ears.

Diagnostics. In determining the indications for surgical treatment, it is important to diagnose the shape of atresia, for which the bone form of this developmental disorder should be excluded. In modern conditions, the most effective diagnostic method is computed tomography with the removal of the structures of the external auditory canal and the tympanum.

Treatment. The goal of the treatment is to restore the lumen of the external auditory canal to ensure sound production and normalization of the auditory function. Treatment consists in surgical plastic of the external auditory canal.

In the presence of membranous atresia, a scroungic approach is applied to the patchwork of the external auditory canal with the excision of the subcutaneous tissue and the formation of the canal of the external auditory canal.

In the postoperative period, a dilated tube is inserted into the newly formed external auditory canal from an areactive synthetic material, which is extracted only for a few minutes during the toilet of the external auditory canal. The newly formed external auditory meatus has a pronounced tendency to scarring and stenosis due to the preserved connective tissue, so the dilator in the external auditory canal is retained for a long time (a month or more).

In bone atresia, surgical treatment is indicated only in the presence of normal structures of the tympanum and inner ear (integrity of the auditory ossicles, normal development of the cochlea and organs of the vestibule), and there should also be normal hearing indicators for tissue sound production. Otherwise, surgical treatment is meaningless.

[1], [2], [3], [4]