The Lingering Effects of Infancy: Positional Plagiocephaly
Positional plagiocephaly, also known as "flat head syndrome," is the most common reason for a flattened skull shape that persists into adulthood. During the first few months of life, a baby's skull is soft and malleable, allowing it to grow and expand. If an infant spends extended periods with their head resting in the same position, such as sleeping on their back, on their side, or in a car seat, the constant pressure can cause a flattening on that part of the skull.
How Infant Head Shape Becomes an Adult Feature
While the condition is treatable in infancy with repositioning techniques or helmet therapy, many cases go unnoticed or untreated. For individuals born before the "Back to Sleep" campaign began in the 1990s, the practice of placing babies on their stomachs to sleep was common, but the increased awareness of SIDS has led to more babies sleeping on their backs, increasing the incidence of plagiocephaly.
- The skull bones fuse and harden significantly by the end of the first year of life.
- If the head shape was already asymmetrical by this point, the underlying bone structure becomes permanent.
- Changes to the head shape after this time are rare and typically require significant trauma or surgical intervention.
A Deeper Medical Cause: Craniosynostosis
While much less common, craniosynostosis is a medical condition that can also lead to an abnormal head shape. This is a congenital defect where one or more of the fibrous joints (sutures) between the bones of a baby's skull fuse prematurely. This premature fusion prevents the skull from expanding normally in that area, forcing it to grow in another direction and resulting in a misshapen head.
Plagiocephaly vs. Craniosynostosis
| Feature | Positional Plagiocephaly | Craniosynostosis |
|---|---|---|
| Cause | External pressure on the infant's skull. | Premature fusion of skull sutures. |
| Effect | Cosmetic flattening of the skull. No effect on brain growth. | Misshapen head, potential for increased pressure on the brain. |
| Treatment | Repositioning, helmet therapy, physical therapy. | Surgical intervention to separate the fused bones. |
| Symptoms | Flat spot on one side or the back of the head. | Often accompanied by a noticeable ridge along the fused suture. |
Other Contributing Factors
- Genetic Predisposition: Some people may simply inherit a skull shape that is flatter at the back. This is not a medical condition but a natural variation in human anatomy.
- Torticollis: A condition in which a newborn's neck muscles are tight or imbalanced, causing their head to tilt and turn to one side.
- Uterine Constraints: A tight fit in the womb can place pressure on the fetus's head, which can lead to a flattened shape at birth.
Is a Flat Head in Adulthood a Problem?
For most adults, the question of why is the back of my head so flat in adulthood? is purely cosmetic. In the vast majority of cases stemming from positional plagiocephaly, there are no associated health problems, neurological issues, or developmental delays.
- Cosmetic Concerns: The primary concern for adults with a flat spot is their appearance, and it may be a source of self-consciousness.
- Hair Loss: A prominent flat spot may sometimes be more prone to hair thinning or baldness, making the area more noticeable.
- Eyeglass Fit: In some rare cases, a significantly asymmetrical head shape can affect the fit of certain items like eyeglasses or protective headgear.
Can a Flat Head in Adulthood Be Corrected?
Correcting a flat head in adulthood is a complex matter. Unlike in infancy, when the skull is still developing, an adult's skull is fully formed and rigid, and non-surgical options are ineffective.
- Surgical Intervention: For those who find the cosmetic appearance of their flat head distressing, there are craniofacial surgeries available.
- Hair and Styling: A more common and less invasive approach is to use hair styling to camouflage the flattened area.
- Lifestyle Changes: For those with minor asymmetry, adjusting sleep positions (though less effective than in infancy) can help to some degree, but will not reverse the underlying bone structure.
When to Consult a Medical Professional
If you have questions about your head shape, or if you suspect it may be a more serious issue than cosmetic plagiocephaly, it's a good idea to consult a doctor. A general practitioner can provide an initial assessment and, if necessary, refer you to a specialist such as a craniofacial surgeon. This is especially important if there are any associated symptoms such as headaches or other neurological issues, though these are extremely rare in cases of simple positional flattening.
For more detailed information on plagiocephaly, consult authoritative sources like the National Institutes of Health.
Conclusion
In conclusion, if you are an adult with a flat spot on the back of your head, it is most likely a benign cosmetic issue resulting from positional plagiocephaly in infancy. While the window for non-surgical correction closes in early childhood, understanding the cause can provide peace of mind. Genetic factors can also play a role, and in rare instances, a medical condition like craniosynostosis could be the cause. For those with significant cosmetic concerns, a medical professional can offer guidance on potential options, but for most, it is a harmless and common variation in skull shape.
