Retrognathism
Pronunciation: ret-roh-NAY-thiz-um
A skeletal condition in which the mandible or maxilla is positioned abnormally far posterior relative to the cranial base and facial profile.
Full Definition
Retrognathism is the opposite of prognathism and describes the rearward positioning of the mandible (mandibular retrognathism, a key feature of Class II skeletal relationships) or maxilla (maxillary retrognathism, contributing to a Class III appearance). Mandibular retrognathism, colloquially called a 'receding chin' or 'weak jaw,' is among the most common skeletal deformities treated in dentofacial orthopedics. Editors must pair it accurately with the correct jaw: mandibular or maxillary retrognathism, not simply 'retrognathism' without qualification in clinical documents. It should not be confused with the dental term 'retrusion.'
Usage
Usage note: Always specify 'mandibular' or 'maxillary' retrognathism unless the broader skeletal pattern is self-evident from context. Distinguish from dental retrusion.
In Context
- "Mandibular retrognathism was identified as the primary skeletal etiology of the patient's Class II malocclusion." — Orthodontic diagnosis report
- "The editor corrected 'retrognathism' to 'mandibular retrusion' after confirming the text referred to tooth position, not jaw position." — Copy-editing annotation