Reading your baby's head shape
Your chiropractor handed you a measurement sheet. This page explains what the numbers mean, why timing matters, and what active care looks like during the window when it makes the most difference.
What you measured
Two measurements. Both tell you more than head shape. They show how the jaw, palate, and nervous system are developing alongside the skull.
CVAI
Measures side-to-side asymmetry. Catches flat spots and shifting patterns before they become obvious. Reported as a percentage — lower is more symmetric.
CI
Measures overall proportion: long and narrow, balanced, or short and wide. Reported as a percentage — it tells you the ratio of width to length, not severity.
What the numbers mean
Severity bands come from published clinical scales. The label describes the pattern. It doesn't predict outcomes on its own.
CVAI — asymmetry
| Label | Range | What it means |
|---|---|---|
| Balanced | < 3.5% | Both sides match closely. |
| Mild | 3.5 – 6.25% | Slight side-to-side difference. Often improves with positioning and tummy time. |
| Moderate | 6.25 – 8.75% | Noticeable asymmetry. 6.25% is the helmet-therapy consideration threshold. |
| Severe | 8.75 – 11% | Active intervention is the typical recommendation. Earlier is better. |
| Very severe | ≥ 11% | Coordinated chiropractic and craniofacial team care. |
CI — head shape
| Label | Range | What it means |
|---|---|---|
| Long & narrow | < 76 | Longer front-to-back than typical (dolichocephaly). |
| Typical | 76 – 81 | Within the proportionate range (mesocephaly). |
| Short & wide | 81 – 85.5 | Wider side-to-side, often associated with prolonged back-laying (brachycephaly). |
| Very short & wide | ≥ 85.5 | Pronounced flat-back proportion (hyperbrachycephaly). |
Why head shape matters
Head-shape changes aren't just cosmetic. They reflect deeper patterns of tension and imbalance that often show up as:
- Mouth-breathing, snoring, or congestion
- Feeding difficulties and reflux
- Torticollis or a strong head-turning preference
- Sensory or emotional dysregulation
- Delayed milestones, restless sleep, or trouble self-soothing
Left unaddressed, the same patterns can carry into later childhood as orthodontic problems, speech delays, or TMJ dysfunction.
The growth window
The skull is most adaptable, and the nervous system most receptive, between 4 and 9 months of age. Earlier is always better.
The goal during this window is to guide your baby toward the most balanced head shape possible. Positioning, tummy time, movement support, and chiropractic care all play a role.
What to do next
Bring the measurement sheet to your next visit and ask your chiropractor what the pattern means specifically for your baby. The numbers are a starting point. Your baby's history, posture, and movement tell the rest of the story.
Early care typically includes a hands-on assessment of the cranial bones and upper neck, positioning and tummy time guidance, support for feeding and sleep, and follow-up measurements to track progress through the growth window.