Pterygomaxillary Fissure
Pronunciation: teh-RIG-oh-mak-SIL-uh-ree
A vertical gap between the posterior wall of the maxillary tuberosity and the pterygoid process of the sphenoid bone, used as a cephalometric landmark.
Full Definition
The pterygomaxillary fissure (Ptm) is a cephalometric reference point located at the juncture of the maxillary tuberosity and the pterygoid plates of the sphenoid bone, visible on lateral cephalograms as a teardrop-shaped radiolucency. It is used to locate the pterygoid vertical, a reference line in the analysis of sagittal jaw relationships, particularly in the Ricketts cephalometric analysis. Editors must note the correct hyphen-free spelling 'pterygomaxillary' and the abbreviation 'Ptm.' Its anatomical complexity makes it a frequent source of mislabelling in manuscripts. Confusion with related structures such as the pterygoid fossa or pterygopalatine fossa should be flagged.
Usage
Usage note: Spell as one unhyphenated word: 'pterygomaxillary.' Abbreviate as 'Ptm' in cephalometric notation.
In Context
- "The Ricketts analysis required identification of the pterygomaxillary fissure to establish the pterygoid vertical." — Cephalometric analysis report
- "The author mislabelled the pterygomaxillary fissure as the pterygopalatine fossa; the editor corrected this anatomical error." — Manuscript revision