A pillow that is too tall for a child pushes the head forward and rotates the chin toward the chest, which narrows the space at the front of the neck and makes it easier for the mouth to fall open. The right height keeps the head in line with the spine, so the jaw is not being pulled anywhere.
This is the least discussed part of a child's sleep and the easiest to check. You can see it from the bedroom door tonight.
The geometry, in one paragraph
Lying on your back, the job of a pillow is to fill the gap between the back of the head and the mattress so the neck keeps its natural curve. Too little and the head tips back. Too much and the head is pushed forward, the neck flexes, and the chin travels toward the chest. On your side, the job changes: the pillow now has to fill the distance from the ear to the point of the shoulder, which is a much bigger gap in an adult than in a child.
That last sentence is the whole problem. Adult pillows are built for adult shoulders.
Try it on yourself
Sit upright and bring your chin down toward your chest. Hold it there. Now try to breathe quietly through your nose with your lips together.
You can do it. It takes more effort, the front of your throat feels compressed, and if you stay there long enough your mouth will want to open.
Now lift your head so your ears sit over your shoulders and do the same thing. Notice the difference in how much work it is.
That is the difference between two pillow heights, and a child holds whichever one they are given for eight hours.
Why children get this wrong more than adults do
Three reasons compound.
The pillow is usually inherited. Standard bedding comes in one size. A child gets the same pillow their parents use, often the spare from a set, because there is no obvious alternative on the shelf.
The proportions are different. A child's head is large relative to their shoulders, and the shoulder-to-ear distance that a side-sleeping pillow has to fill is much shorter. A height that supports an adult neck overfills a child's.
Nobody checks. Pillow height is not on any checklist. It is not part of a dental visit, a paediatric review or a sleep conversation. It is invisible precisely because it is so ordinary.
How to check your own child tonight
Wait until they are asleep and look from the side, at eye level with the bed.
- On their back: is the chin roughly level, or is it tipped down toward the chest? You are looking for the line from the chin to the throat to stay open, not folded.
- On their side: is the nose in line with the middle of the chest, or is the head tipped up toward the ceiling or dropped down toward the mattress?
- Either way: are the lips together or apart?
- In the morning: is there a damp patch on the pillow, and are the lips dry?
If the chin is folded and the mouth is open, you have found something you can change.
What changing it does and does not do
Let us be precise, because this is where pillow marketing usually stops being honest.
What it changes: the position of the head and the angle of the jaw for the hours the child is asleep. That is a genuine variable and it is one of the few that can be altered without asking anything of the child.
What it does not change: an enlarged adenoid, an allergy, a deviated septum, a narrow arch, or a habit that has already formed. If the nose is physically blocked, a better pillow does not unblock it. Position is one contributing factor among several, and it is the geometric one.
Anyone telling you a pillow resolves mouth breathing is overselling it. What a pillow can do is stop the night from working against everything else.
Getting the height right
Height should be matched to the child's frame, not their age. Ages on a size chart are shorthand for typical shoulder width, and children are not typical.
The rule we use: go by shoulder width and the bed rather than the birthday. If the shoulders are wider than the pillow is deep, take the larger size. A six-year-old on a full-size single bed is usually in the larger one.
The Little Otter Pillow comes in two sizes — 30 × 50 cm for ages three to six, and 40 × 60 cm for ages seven to fourteen — both contoured to 7 cm at the neck. It is designed around the position problem described above and nothing else.
It supports orthodontic treatment and replaces no part of it. It is not a medical device, and it does not treat, cure or prevent any condition. Not suitable for children under three.
Medically reviewed by Dr Helen Woods, airway-focused pediatric dentist, with seventeen years specialising in pediatric airways.