The relations of the mastoid segment of the facial canal to surrounding structures in congenital middle ear malformations

Congenital Anomalies of the Ear Canal

Congenital anomalies of the external auditory canal (EAC) are classically divided into congenital aural atresia (CAA) and congenital aural stenosis (CAS). CAA can present as an isolated anomaly, unilateral or bilateral, or in the setting of a craniofacial syndrome. Hearing testing (ABR with air and bone conduction thresholds for both ears) early in the perinatal period is important to document hearing thresholds. Hearing status thus informs parent counseling on options for hearing habilitation: Bone conducting technology is a must for children with bilateral CAA to support normal speech and language development. Bone conducting technology should be considered for children with unilateral CAA; benefits are unclear. In select candidates, atresia repair can provide improved hearing with a clean, dry, epithelialized ear canal. First branchial cleft cyst or sinus is rare; high index of suspicion is needed to diagnose along with high-resolution CT. Congenital aural stenosis (CAS) is a rare condition, and hearing testing should be similar to that in children with CAA. Early (age 4-5) CT imaging is recommended in the setting of a canal <2 mm or pinpoint canal to evaluate for trapped skin/ear canal cholesteatoma.