A dent or depression on the head naturally triggers concern. Head indentations are real, presenting a spectrum of causes that range from common, temporary variations to signs of a more serious underlying condition. Understanding the physical nature of these depressions is the first step in assessing their importance. This article explains the different types of indentations, details the causes specific to infants and those affecting all ages, and outlines when medical evaluation is warranted.
Understanding Different Types of Head Indentations
What is perceived as a “head dent” generally falls into two categories: superficial or structural. A superficial dent involves the soft tissues covering the skull (skin, fat, or muscle) and does not affect the bone beneath. These indentations are often transient, resulting from localized pressure or temporary swelling that resolves on its own.
In contrast, a structural indentation involves the bony plates of the cranium itself. The skull is a collection of bones joined by fibrous joints called sutures. In infants, these sutures meet at wider, membranous spaces known as fontanelles, or soft spots.
The flexibility of developing bones means external forces or underlying growth issues can alter the contour of the skull. A dent that feels firm or fixed upon gentle touch is more likely to be structural. Differentiating between these two types is the initial step a healthcare provider takes during an examination.
Positional and Growth-Related Causes in Infants
The most frequent cause of an altered head shape in infants is the malleability of their rapidly growing skulls. This is commonly known as positional plagiocephaly, which presents as a flattening or indentation on one side of the back of the head. Since the “back to sleep” campaign began, this type of flattening has become widespread, affecting up to 25% of infants who sleep on their backs.
Constant pressure on the same area of the skull bone over time prevents its normal outward growth. Fortunately, positional plagiocephaly is a cosmetic issue that does not impact brain development or function.
A newborn’s head shape is also commonly affected by the journey through the birth canal, a process known as molding. The pliable skull bones temporarily overlap to facilitate delivery, which can result in an elongated or uneven appearance. This temporary deformation typically resolves quickly, often within the first six weeks of life.
Management often centers on repositioning therapy, encouraging the baby to spend less time with pressure on the flattened area. This includes supervised tummy time when awake and alternating the direction the baby faces in the crib to promote pressure relief. For older infants where the condition has persisted, a custom-fitted cranial molding helmet may be recommended between three and six months of age to gently redirect growth.
Traumatic and Pathological Causes
A dent that appears suddenly following an injury, especially in adults or older children, may indicate a depressed skull fracture. This occurs when a severe, localized blow forces a section of the skull bone inward toward the brain. The indentation is a direct sign of the bone breaking and sinking below the normal surface level.
This type of fracture is concerning because the inward-pressed bone fragment can place pressure on or lacerate the underlying brain tissue. Symptoms often include severe headache, confusion, nausea, or loss of consciousness, signaling a medical emergency. Neurosurgical consultation is required to assess the severity and determine if the fragment needs to be elevated.
Another structural cause, particularly in infants, is craniosynostosis, a rare birth defect where one or more of the skull sutures fuse prematurely. This early fusion prevents the skull from expanding normally, forcing the head to grow unevenly and resulting in abnormal shapes, which can manifest as a dent or ridge. This condition affects approximately one in every 2,500 live births and can be associated with increased pressure inside the skull if multiple sutures are involved.
In adults, structural dents can rarely be linked to certain systemic bone disorders or localized tissue conditions. Examples include Paget’s disease of bone, which interferes with bone replacement, or localized tissue atrophy where bone or soft tissue is slowly lost. A localized dent can also be a sign of a bone-destructive tumor.
When a Head Dent Requires Medical Attention
While many head dents are harmless cosmetic variations or temporary positional changes, certain signs require immediate medical attention. Any dent that appears suddenly after a significant fall or blow to the head must be evaluated immediately to rule out a depressed skull fracture. This is especially true if the dent is accompanied by symptoms like persistent vomiting, severe headache, slurred speech, or changes in vision or consciousness.
For infants, a dent that appears fixed, is accompanied by a failure to thrive, or involves a premature closing of the soft spot should be checked for craniosynostosis. In adults, a new dent that appears spontaneously, grows larger, or is associated with localized pain, fever, or unexplained neurological symptoms warrants a visit to a physician.
The diagnostic process begins with a detailed physical examination and medical history. If a structural issue is suspected, a physician will typically order imaging studies. A Computed Tomography (CT) scan is often the preferred tool, as it provides highly detailed images of the bone structure to accurately assess the extent of any fracture or premature suture fusion.