Wiktionary
retrognathism
n. (context anatomy English) The quality of being retrognathic.
Wikipedia
Retrognathism
Retrognathia (or retrognathism) is a type of malocclusion which refers to an abnormal posterior positioning of the maxilla or mandible, particularly the mandible, relative to the facial skeleton and soft tissues.
A retrognathic mandible is commonly referred to as an overbite, though this terminology is not used medically.