The bregma is the anatomical point on the skull at which the coronal suture is intersected perpendicularly by the sagittal suture.
Structure
The bregma is located at the intersection of the
coronal suture and the
sagittal suture on the superior middle portion of the calvaria.
It is the point where the
frontal bone and the two
meet.
Development
The bregma is known as the anterior fontanelle during infancy. The anterior fontanelle is membranous and closes in the first 18-36 months of life.
Clinical significance
Cleidocranial dysostosis
In the
birth defect cleidocranial dysostosis, the anterior fontanelle never closes to form the bregma.
Surgical landmark
The bregma is often used as a reference point for stereotactic surgery of the
brain.
It may be identified by blunt scraping of the surface of the skull and washing to make the meeting point of the sutures clearer.
Neonatal examination
Examination of an infant includes palpating the anterior fontanelle.
It should be flat, soft, and less than 3.5cm across.
A sunken fontanelle indicates dehydration, whereas a very tense or bulging anterior fontanelle indicates raised intracranial pressure.
Height assessment
Cranial height is defined as the distance between the bregma and the midpoint of the
foramen magnum (the basion).
This is strongly linked to more general growth.
This can be used to assess the general health of a deceased person as part of an archaeological excavation, giving information on the health of a
population.
Etymology
The word "bregma" comes from the Ancient Greek βρέγμα (
brégma), meaning the bone directly above the brain.
[Liddell & Scott, Greek-English Lexicon]
== Additional images ==
External links
