Anterior Cranial Base
The portion of the cranial base from the sella turcica to the nasion, used in cephalometric analyses as a stable reference structure for measuring facial growth.
Full Definition
The anterior cranial base (commonly denoted S-N on cephalometric tracings) spans from the sella turcica (centre of the pituitary fossa) to the nasion (frontonasal suture). Because this region completes growth relatively early, it serves as a widely accepted reference plane in longitudinal studies of dentofacial development. Editors working on cephalometric reports must ensure that 'anterior cranial base' is not conflated with the broader term 'cranial base' or the posterior cranial base. The structure is central to the derivation of SNA, SNB, and SNPg angles and is routinely abbreviated S-N in technical text.
Usage
Usage note: Hyphenate when used as a compound modifier: 'anterior-cranial-base length'. Use the abbreviation S-N only after first full use in a document.
In Context
- "Growth rotations were assessed relative to the anterior cranial base across four serial cephalograms." — Research article
- "The anterior cranial base length (S-N) was within the normative range for the patient's chronological age." — Clinical case report