Anatomy of the Fetal Skull

Composed of several bones: frontal, parietal, temporal, occipital, and sphenoid.
Fontanelles: soft spots where bones have not yet fused.
- Anterior fontanelle: largest, located between frontal and parietal bones.
- Posterior fontanelle: smaller, located between parietal and occipital bones.
Basic structure includes:
- Neurocranium: encases the brain.
- Viscerocranium: forms the face.
Mandible is articulated in two halves.

Early Development (Weeks 1-8):
- Initial bone formation begins.
- Neural tube closure occurs.
Mid Gestation (Weeks 9-20):
- Rapid growth and ossification take place.
- Distinct cranial features develop.
Late Gestation (Weeks 21-40):
- Further ossification and bone fusion.
- Fontanelles remain for flexibility during birth.

Fontanelle examination can indicate hydration status and intracranial pressure.
Abnormalities can lead to conditions like:
- Craniosynostosis: premature fusion of skull sutures.
- Hydrocephalus: abnormal accumulation of cerebrospinal fluid.
Examination helps assess growth and neurological development during infancy.

Asymmetry: Common due to pressure during fetal position.
Molding: Changes in shape during birth process to fit the birth canal.
Size: Variation in head circumference can occur; requires monitoring.
Positioning: Occipital and frontal bone differences may be noted; typically resolves.

Fibrous joints that connect the bones of the skull.
Major sutures include:
- Coronal suture: connects frontal and parietal bones.
- Sagittal suture: runs along the midline, connecting the two parietal bones.
- Lambdoid suture: connects parietal bones to the occipital bone.
- Squamous suture: connects temporal bones to parietal bones.
Sutures allow for growth and flexibility during birth.

Composed of several bones: frontal, parietal, temporal, occipital, and sphenoid.
Fontanelles are soft spots where skull bones have not fused, allowing flexibility during birth.
Anterior fontanelle is the largest, located between the frontal and parietal bones.
Posterior fontanelle is smaller, situated between the parietal and occipital bones.
Basic structure includes:
- Neurocranium, which encases the brain for protection.
- Viscerocranium, responsible for forming the facial structure.
Mandible is articulated in two halves, providing movement for chewing and speaking.

Early Development (Weeks 1-8):
- Initial bone formation begins, crucial for skeletal development.
- Neural tube closure is a vital process preventing congenital defects.
Mid Gestation (Weeks 9-20):
- This period features rapid growth and ossification of cranial bones.
- Distinct cranial features, such as eye sockets and nasal structure, begin to take shape.
Late Gestation (Weeks 21-40):
- Further ossification occurs, solidifying the skull structure.
- Fontanelles remain unossified for flexibility during the birthing process.

Fontanelle examination is critical in assessing hydration status and intracranial pressure in neonates.
Abnormalities in the skull can lead to conditions like:
- Craniosynostosis, characterized by the premature fusion of skull sutures.
- Hydrocephalus, which involves abnormal accumulation of cerebrospinal fluid in the brain.
Regular examination of the skull helps monitor growth and neurological development during infancy.

Asymmetry in skull shape is common, often due to the pressure exerted in the fetal position.
Molding refers to the changes in skull shape during the birth process to facilitate passage through the birth canal.
Head circumference can vary; deviations require monitoring for potential issues.
Positioning differences between occipital and frontal bones are typically transient and resolve over time.

Skull sutures are fibrous joints connecting the bones of the skull, allowing for growth.
Major sutures include:
- Coronal suture, connecting frontal and parietal bones.
- Sagittal suture, running along the midline connecting the two parietal bones.
- Lambdoid suture, connecting parietal bones to the occipital bone.
- Squamous suture, connecting temporal bones to parietal bones.
Sutures provide flexibility during birth and accommodate brain growth in early childhood.

The fetal skull consists of several non-fused bones to provide flexibility during childbirth.
Major components include:
- Frontal Bone: Forms the forehead.
- Parietal Bones: Two bones that create the sides and roof of the skull.
- Temporal Bones: Located below the parietal bones and contain ear structures.
- Occipital Bone: Creates the back and base of the skull.
Fontanelles: Soft spots between bones critical for skull molding during delivery.
- Anterior Fontanelle: Diamond-shaped.
- Posterior Fontanelle: Triangular-shaped.

Early Development: Starts as a cartilage model around 6 weeks gestation; ossification begins at week 7.
Mid-gestation: Characterized by rapid growth and initial hardening of cranial bones.
Late Gestation: Fontanelles remain open to support additional brain growth, with full ossification usually completed by ages 2-3.

Molding: The ability of the fetal skull to adapt its shape during labor to facilitate passage through the birth canal.
Intracranial Pressure: Skull shape abnormalities or early suture closure may indicate increased intracranial pressure.
Hydrocephalus: Condition that causes skull enlargement due to excess cerebrospinal fluid, resulting in distinct skull features.

Shape Changes: Skull shape can differ based on fetal position (e.g., breech versus vertex).
Size Variability: Variation in head circumference is normal; however, significant discrepancies may signal underlying health issues.
Suture Patterns: Variations exist in the timing and patterns of suture closures.

Definition: Fibrous joints connecting cranial bones that allow for growth and flexibility.
Major sutures include:
- Coronal Suture: Between the frontal and parietal bones.
- Sagittal Suture: Between the two parietal bones.
- Lambdoid Suture: Between the parietal and occipital bones.
- Squamous Suture: Between the parietal and temporal bones.
Function: Facilitates skull growth during infancy and enables the molding process during delivery.