What is the medical term for a flattened occiput?

Medical Term for Flattened Occiput

The medical term for flattened occiput is positional plagiocephaly or deformational plagiocephaly when it occurs due to external forces, and occipital plagiocephaly when referring specifically to the flattened occipital region. 1, 2

Types of Occipital Flattening

There are two main types of occipital flattening:

1. Deformational/Positional Plagiocephaly:

   • Asymmetric flattening of one side of the occipital region
   • Results in a parallelogram-shaped skull
   • Most common form (>99% of cases with occipital flattening) 3
   • Caused by external pressure on the developing skull

2. Deformational Brachycephaly:

   • Symmetric flattening of the entire occipital region
   • Results in a foreshortened head in the anterior-posterior dimension
   • Wider than normal skull 2

3. Lambdoid Synostosis:

   • Extremely rare (approximately 1% of cases with occipital flattening) 3
   • Caused by premature fusion of the lambdoid suture
   • True craniosynostosis requiring surgical intervention

Distinguishing Features

Deformational Plagiocephaly:

• Ipsilateral ear is anteriorly displaced in 97% of cases 4
• May be associated with torticollis (neck muscle tightness)
• More common on the right side (61%) than the left (30%) 4
• Often presents with minor contralateral frontal flattening (52%) 4
• Male:female ratio of 3:1 4

Lambdoid Synostosis:

• Ear position is variable (can be anterior, posterior, or symmetric) 4
• Requires CT imaging for definitive diagnosis
• Represents only 3.4% of all primary operations for craniosynostosis 4

Diagnostic Approach

Clinical examination is typically sufficient for diagnosis of deformational plagiocephaly. Imaging is rarely necessary except when clinical diagnosis is equivocal or true lambdoid synostosis is suspected 2.

When imaging is needed:

• 3D cranial topographical imaging
• Skull x-rays
• Ultrasound
• CT scanning (reserved for suspected lambdoid synostosis) 2

Clinical Significance

Positional plagiocephaly is associated with supine sleeping position (OR: 2.5) and is most likely to result from:

• Not varying the infant's head position during sleep
• Insufficient supervised tummy time
• Limited upright positioning when awake 1

In healthy children, the incidence of positional plagiocephaly decreases spontaneously from 20% at 8 months to 3% at 24 months of age 1.

Management

For deformational plagiocephaly:

1. Repositioning and physical therapy:

   • First-line treatment for mild to moderate cases
   • Includes neck stretching exercises for associated torticollis
   • Supervised tummy time when awake 1, 2

2. Cranial molding helmets:

   • For moderate to severe cases or when repositioning fails
   • More effective when started before 6 months of age
   • Treatment typically continues until 12 months or correction plateaus 2
   • Provides more rapid and greater degree of correction than repositioning alone 2

For lambdoid synostosis:

• Surgical correction is required 5, 3

Prevention

• Supervised tummy time while awake
• Alternating the infant's head position during sleep (right/left)
• Avoiding prolonged time in car seats, swings, or bouncy seats
• The American Academy of Pediatrics recommends against using positioning pillows due to SIDS risk 1, 2

Early identification and intervention for occipital flattening is important, as treatment initiated before 6 months of age yields better outcomes 2.