Congenital Auricular Malformations: Description of Anomalies and Syndromes

Abstract

Half of the malformations in the ear, nose, and throat region affect the ear. Malformations of the external ear (pinna or auricle with external auditory canal [EAC]) are collectively termed microtia. Microtia is a congenital anomaly that ranges in severity from mild structural abnormalities to complete absence of the external ear (anotia). Microtia occurs more frequently in males (∼2 or 3:1), is predominantly unilateral (∼70-90%), and more often involves the right ear (∼60%). The reported prevalence varies geographically from 0.83 to 17.4 per 10,000 births. Microtia may be genetic (with family history, spontaneous mutations) or acquired. Malformations of the external ear can also involve the middle ear and/or inner ear. Microtia may be an isolated birth defect, but associated anomalies or syndromes are described in 20 to 60% of cases, depending on study design. These generally fit within the oculo-auriculo-vertebral spectrum; defects are located most frequently in the facial skeleton, facial soft tissues, heart, and vertebral column, or comprise a syndrome (e.g., Treacher Collins syndrome). Diagnostic investigation of microtia includes clinical examination, audiologic testing, genetic analysis and, especially in higher grade malformations with EAC deformities, computed tomography (CT) or cone-beam CT for the planning of surgery and rehabilitation procedures, including implantation of hearing aids.

A unique anomaly of the ear: Oculo‐auriculo‐vertebral spectrum or an isolated disruption?

“…Due to the variable expressivity, there is no consensus regarding the minimum diagnostic criteria for OAVS . Generally, the minimal criteria for OAVS are considered to be unilateral microtia, hypoplasia of the mandible, epibulbar dermoids, and anomalies of the cervical spine . Nearly all patients with OAVS have some degree of hemifacial microsomia, resulting from maxillary and/or mandibular hypoplasia.…”

Ear mould for congenital auricular deformities: a protocol for systematic review and meta-analysis

“…Although Matsuo K et al [8] in Japan found that different types of CADs have the tendency of natural improvement, there is still a lack of high-quality studies to demonstrate the degree of natural improvement. Therefore, it is suggested that treatment and correction should be carried out as early as possible [9][10][11].…”

Target sequencing of 307 deafness genes identifies candidate genes implicated in microtia

“…Grade III displays only soft tissue rudiments, with no definable structures of the auricle. Grade IV is the extreme case in which the external ear and auditory canal are absent, a condition called anotia [ 7 ].…”

“…In addition, many syndromic microtia patients present with inner ear malformations, including branchio-oculofacial, branchio-oto-renal/branchio-otic, CHARGE (coloboma, heart defects, choanal atresia, retarded growth and development, genital abnormalities, ear anomalies), Nager (preaxial acrofacial dysostosis), Treacher Collins, Wildervanck (cervico-oculo-acoustic), LAMM (congenital deafness, inner ear agenesis, microtia, microdontia) and lacrimo-auriculodento-digital (LADD) syndromes, among others. The frequent malformations of the inner ear are common cavity, cochlear aplasia, Mondini defect, enlarged vestibular aqueduct, abnormal/absent semicircular canals, and bulbous IAC (internal auditory canal) [ 7 ]. Conductive hearing loss, sensorineural hearing loss, and mixed hearing loss can all be found in microtia patients [ 7 ].…”

“…The frequent malformations of the inner ear are common cavity, cochlear aplasia, Mondini defect, enlarged vestibular aqueduct, abnormal/absent semicircular canals, and bulbous IAC (internal auditory canal) [ 7 ]. Conductive hearing loss, sensorineural hearing loss, and mixed hearing loss can all be found in microtia patients [ 7 ]. Given these observations, we propose that malformations of the external/middle ear and inner ear may reflect the actions of certain genes in common.…”