Prognathism, also called Habsburg jaw or Habsburgs' jaw primarily in the context of its prevalence amongst members of the House of Habsburg, 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 general dentistry, oral and maxillofacial surgery, and orthodontics, this is assessed clinically or radiographically (cephalometrics). The word prognathism derives from 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.