The crown of the head is an anatomical landmark that represents the highest point of the human skull, a region with significance that changes from infancy to adulthood. This area is often vaguely defined in everyday conversation, yet it is a complex intersection of bone, protective tissue, and specialized hair follicles. Understanding the crown’s precise location, underlying structures, and common health issues provides a clearer picture of its role in both development and overall health.
Defining the Crown of the Head
The crown is commonly identified as the uppermost, rounded part of the skull, situated superior to the temporal regions and posterior to the forehead. Anatomically, this area is also referred to as the vertex, meaning the highest point. It can be located by tracing an imaginary line from ear to ear and another from the nose to the back of the neck; the crown is where these lines intersect at the top of the head.
This region is often recognized for the characteristic spiral or whorl pattern of hair growth. Establishing the boundaries of the crown is important because it dictates the location for features like skeletal joints and patterns of hair loss.
Unique Anatomical Structures
The adult crown is formed by the fusion of several flat cranial bones, which together create the protective vault for the brain. The primary skeletal components include parts of the two parietal bones and the superior edge of the occipital bone, held together by immovable joints known as sutures.
The crown is the meeting point for significant sutures. The sagittal suture runs along the midline, joining the two parietal bones. The coronal suture separates the frontal bone from the parietal bones, while the lambdoid suture connects the parietal bones with the occipital bone at the back.
Overlying this bony structure is the scalp, which is composed of five distinct layers that act as a protective barrier. The three outermost layers—the skin, dense connective tissue, and the tough aponeurosis—are securely bound together. This structure provides mechanical protection and is rich in blood vessels and nerves.
Developmental Significance of the Crown
In infants, the crown is not a solid bony structure but a flexible area marked by the largest of the “soft spots,” the anterior fontanelle. This diamond-shaped membranous gap is located where the frontal and parietal bones meet. It allows the bone plates to overlap during birth, enabling the head to pass through the narrow birth canal.
The anterior fontanelle is essential for accommodating the rapid growth of the infant brain. This soft spot typically measures between 0.6 and 3.6 centimeters at birth and usually closes completely between nine and eighteen months of age. Pediatricians closely monitor this area, as its appearance indicates health status.
A slight, visible pulse or a soft, flat feel is normal. A sunken appearance can be a sign of dehydration, while a bulging or tense fontanelle, especially when the infant is not crying, may suggest increased intracranial pressure. The fontanelle provides a direct window for assessing an infant’s hydration and neurological health.
Common Health Concerns
The crown of the head is a susceptible site for common dermatological and hair-related conditions. The most well-known concern in adults is androgenetic alopecia, or pattern baldness. This condition is genetically determined and linked to the hair follicles’ sensitivity to the hormone dihydrotestosterone (DHT).
In men, hair loss frequently begins or is most pronounced at the crown (vertex), often progressing to a horseshoe-shaped pattern. DHT causes the miniaturization of hair follicles, leading to shorter, thinner strands and eventual hair loss. In women, pattern hair loss often presents as diffuse thinning or widening of the center part at the crown, usually preserving the frontal hairline.
In infants, a common condition affecting the crown is seborrheic dermatitis, known as “cradle cap.” This manifests as thick, greasy, and yellowish scaly patches on the scalp. It is thought to involve an overgrowth of the Malassezia yeast combined with excess oil production. Cradle cap is harmless and typically clears up on its own within the baby’s first year of life.