THE FONTANELLES

In the skull of the newborn, there are some gaps in the vault of the skull that are filled by membrane. These gaps are called FONTANELLES or FONTICULI. They are located in relation to the angles of the parietal bone as follows:

The fontanelles disappear (by growth of the bones around them) at different ages after birth.

FONTANELLE: ANTERIOR (Bregma)

CHARACTERISTIC:

• Diamond shape
• Largest fontanelle
• Lies between 2 parietal & 2 frontal bones

TIME OF CLOSURE:18-24 months

FONTANELLE: POSTERIOR (OCCIPITAL)

CHARACTERISTIC:

• Triangular shape
• Lies between 2 occipital & parietal bones

TIME OF CLOSURE: 2-3 months after birth

FONTANELLE: ANTEROLATERAL (Sphenoidal)

CHARACTERISTIC:

Present in relation to the antero-inferior angle of the parietal bone

TIME OF CLOSURE: 2-3 months

FONTANELLE: POSTEROLATERAL (Mastoid)

CHARACTERISTIC:

Present in relation to the postero-inferior angle of the parietal bone

TIME OF CLOSURE: 12-18 months

[NOTE: Anterior fontanelle is the last to close and has a high variation in the time of closure

Reference:

1.Textbook of HUMAN OSTEOLOGY (Inderbir Singh, 3rd Edition)