Prognathism
Pronunciation: prog-NAY-thiz-um
A condition in which the jaw (maxilla, mandible, or both) protrudes beyond the normal antero-posterior relationship with the skull base, assessed clinically and cephalometrically.
Full Definition
Prognathism describes the forward protrusion of one or both jaws relative to the cranial base, classified as maxillary prognathism (excessive forward position of the upper jaw) or mandibular prognathism (excessive forward position of the lower jaw). In orthodontic and orthognathic records, accurate qualified use—'mandibular prognathism' versus 'maxillary prognathism'—is essential. The term is distinct from 'protrusion,' which typically refers to individual tooth position rather than jaw-base position. Editors should ensure the qualifying adjective is always present to avoid ambiguity.
Usage
Usage note: Always qualify as 'mandibular' or 'maxillary' prognathism. Do not use interchangeably with 'proclination,' which describes tooth inclination rather than jaw-base position.
In Context
- "The patient presented with mandibular prognathism and a significant negative overjet, requiring combined orthodontic and surgical management." — Initial assessment letter
- "The author uses 'prognathism' without qualification on three occasions; clarify whether mandibular or maxillary prognathism is intended each time." — Manuscript query