Wikipedia
Otocephaly
Otocephaly (from the Greek words οτο, meaning “ear”, and κεφάλη, meaning "head") is a type of head disorder ( cephalic disorder).
This is a lethal condition in which the primary feature is the total or virtual absence of the lower jaw (a developmental anomaly called agnathia). The “oto” in the name refers to the relationship of the ears to the face in this disorder.
The condition is considered lethal because of a poorly functioning airway.
In otocephaly, agnathia may occur alone or together with holoprosencephaly.