The bregma is the anatomical point on the skull at which the

coronal suture The coronal suture is a dense, fibrous connective tissue joint that separates the two parietal bones from the frontal bone of the skull. Structure The coronal suture lies between the paired parietal bones and the frontal bone of the skull. ...

is intersected perpendicularly by the

sagittal suture The sagittal suture, also known as the interparietal suture and the ''sutura interparietalis'', is a dense, fibrous connective tissue joint between the two parietal bones of the skull. The term is derived from the Latin word ''sagitta'', mean ...

Structure

The bregma is located at the intersection of the

and the

on the superior middle portion of the calvaria. It is the point where the

frontal bone The frontal bone is a bone in the human skull. The bone consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, pa ...

and the two

parietal bone The parietal bones () are two bones in the skull which, when joined at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named ...

s meet.

Development

The bregma is known as the

anterior fontanelle The anterior fontanelle (bregmatic fontanelle, frontal fontanelle) is the largest fontanelle, and is placed at the junction of the sagittal suture, coronal suture, and frontal suture; it is lozenge-shaped, and measures about 4 cm in its anter ...

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 A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities c ...

cleidocranial dysostosis Cleidocranial dysostosis (CCD), also called cleidocranial dysplasia, is a birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close togethe ...

, the

never closes to form the bregma.

Surgical landmark

The bregma is often used as a reference point for stereotactic surgery of the

brain The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head ( cephalization), usually near organs for special ...

. 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

. 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 foramen magnum ( la, great hole) is a large, oval-shaped opening in the occipital bone of the skull. It is one of the several oval or circular openings (foramina) in the base of the skull. The spinal cord, an extension of the medulla oblonga ...

(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 In archaeology, excavation is the exposure, processing and recording of archaeological remains. An excavation site or "dig" is the area being studied. These locations range from one to several areas at a time during a project and can be cond ...

, giving information on the health of a

population Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using ...

Etymology

The word "bregma" comes from the Ancient Greek βρέγμα (''brégma''), meaning the bone directly above the brain.Liddell & Scott, ''Greek-English Lexicon''