Anterior Nasal Spine
Also written as: ANS — Anterior Nasal Spine
A bony projection at the base of the nasal septum, visible on periapical and cephalometric films as a sharp radiopaque landmark in the midline maxillary region.
Full Definition
The anterior nasal spine (ANS) is a pointed, midline bony prominence at the inferior margin of the nasal aperture, formed by the fusion of the two maxillary bones. On dental radiographs, it appears as a distinctive radiopaque V-shaped or spine-like projection superimposed over the roots of the upper central incisors. It is a key skeletal landmark used in cephalometric tracing and analysis. Editors working on radiology reports must avoid confusing it with the incisive foramen or nasal septum, which appear in the same region. It is routinely abbreviated ANS in cephalometric reports.
Usage
Usage note: When abbreviated, use 'ANS' on second reference after the full term is established. Do not confuse with 'PNS' (posterior nasal spine) in cephalometric reports.
In Context
- "The anterior nasal spine was clearly visible as a radiopaque projection superimposed between the apices of teeth 11 and 21." — Periapical radiograph report
- "ANS was identified and traced as part of the skeletal analysis in the lateral cephalogram." — Cephalometric analysis report