Why does my child grind teeth at night?

Can you hear your child grinding their teeth through the bedroom wall? That grating, crunching sound is more common than most parents realise, and it can carry on into the teenage years. Tooth grinding, or bruxism to give it its clinical name, wears down precious enamel, leaves the jaw stiff and sore in the morning, and breaks up the deep sleep growing children need. The good news is that once you understand the reasons behind it, there is usually a lot you can do.

Because it happens in sleep, most children have no idea they grind their teeth. You might be the first to notice, either from the sound or from a child who wakes with a headache or an aching jaw. Teenagers clench and grind too, often when they are wound up about school, friends or exams. A wonky bite, breathing problems, sleep apnoea or even a stressful day can play their roles in teeth grinding, but what gets talked about far less is nutrition. In my thirty years in clinic I have seen again and again that certain nutrient shortfalls keep a child’s nervous system on high alert through the night, and teeth grinding is one way this tension shows up. Here is what I look at first.

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Vitamin D and the sleeping brain

Vitamin D does far more than build strong bones. Receptors for it sit throughout the brainstem and the sleep centres of the brain, which is why a shortfall in vitamin D can unsettle the whole night. In one case controlled study, adults with sleep bruxism had significantly lower vitamin D levels and higher anxiety scores than those who did not grind their teeth, and low vitamin D made grinding several times more likely. A second study found that the more severe the grinding, the lower the vitamin D blood level tended to be.

Children run low in vitamin D most easily in winter and early spring, when the sun sits too low in the UK for our skin to make any. If your child grinds their teeth more in the colder months, vitamin D supplementation is worth exploring. There is some vitamin D in oily fish, egg yolks, grass fed meat and fortified foods, though food alone rarely fills the gap in a British winter. This is why the UK recommends that all children over one year of age take 10 micrograms (400IU) of vitamin D daily during the autumn and winter months.

Magnesium, the great muscle relaxer

Magnesium is the mineral I recommend most often when a child grinds their teeth. Magnesium is a vital mineral that is involved in around 300 reactions in the body, and one of its key jobs is helping muscles let go after they contract. When there is a shortfall in magnesium, muscles are tight and twitchy, the jaw included, and the nervous system struggles to shift out from a high alert state to calm at bedtime. Magnesium also helps regulate melatonin, the hormone that guides the sleep cycle, so you can see why not consuming enough might show up as a clenched, grinding jaw.

Getting enough magnesium into a small child through food alone is really hard. The best sources are dark green leafy vegetables, nuts, seeds, wholegrains, beans and a little dark chocolate, none of which feature heavily in the average child’s day. This is where a targeted top up through supplements, or a warm magnesium salt bath before bed, can help, often quite quickly. The gentler forms such as bisglycinate are kinder on a young tummy.

Iron and restless nights

Iron is one of the most important minerals for a healthy central nervous systemso when iron stores dip a child’s whole demeanour can shift. Low iron is one of the key drivers of restless, broken sleep in children, and teeth grinding comes along with that restlessness. Studies from paediatric sleep clinics show that children with fidgety, disturbed sleep very often have low ferritin, the marker for the body’s iron stores, and that topping iron back up settles their nights. Ferritin can be low well before a standard test finds anaemia, so a child can be affected while still appearing to have a normal blood count.

Children who eat little red meat or few greens are the most likely to fall short of enough iron. Good sources include red meat, liver, beans, lentils, tofu and dark leafy greens, and a little vitamin C alongside, such as a few berries, helps the body absorb the iron from plants.

Consider threadworm

Here is one that surprises many parents. Threadworm, and less often roundworm, is a possible trigger of teeth grinding that is well worth ruling out in younger children. It is extremely common in UK primary schools and nurseries, so this is no reflection on a clean and happy home, simply a fact of childhood.

The research picture is still a mixed one. Some studies in children have found more teeth grinding among those with intestinal parasites, while others have found no clear link, so I would never call worms a confirmed cause.

It seems to work indirectly: the worms cause nighttime itching around the bottom that disturbs sleep and puts the nervous system on edge, and heavy infestations can nibble away at the very nutrients, iron and magnesium among them, that keep the jaw calm. The reason I mention it is that it is so easy to check and to sort out. If your child has an itchy bottom at night, is unusually restless, or has started grinding their teeth out of the blue, it is worth crossing it off the list, and your pharmacist can point you to a simple remedy for the whole family.

Round up

Tooth grinding in children and teenagers is common, and while it can be alarming to listen to, it is very often your child’s body signalling that something is out of balance, and that something is frequently nutritional.

The reassuring part is that these are all things we can look into properly. A little testing shows where your child’s nutrient levels are at, so any change to their diet or any top up can be matched to their age and needs. If your child is grinding their teeth at night and you would like to get to the root of it, the NatureDoc Children team would be glad to help. And if you know another worn out parent lying awake to that all too familiar sound, do share this with them.