Prognathism

Prognathism is a positional relationship of the mandible or maxilla to the skeletal base where either of the jaws protrudes beyond a predetermined imaginary line in the coronal plane of the skull.

In the case of mandibular prognathism (never maxillary prognathism), this is often also referred to as Habsburg chin, Habsburg's chin, Habsburg jaw or Habsburg's jaw especially when referenced with the context of its prevalence amongst historical members of the House of Habsburg.

Mandibular prognathism is typically pathological, whereas maxillary prognathism is often the result of normal human population variation.

In general dentistry, oral and maxillofacial surgery, and orthodontics, this is assessed clinically or radiographically (cephalometrics). The word prognathism derives from the Greek πρό (pro, meaning 'forward') and γνάθος (gnáthos, 'jaw'). One or more types of prognathism can result in the common condition of malocclusion, in which an individual's top teeth and lower teeth do not align properly.