Prognathism is the positional relationship of the mandible and/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 pro (forward) and γνάθος gnathos (jaw). One or more types of prognathism may result in the common condition of malocclusion, in which an individual's top teeth and lower teeth do not align properly.