Teeth move in mysterious ways

ID-100144805I had braces when I was a teenager. Not the fancy metal braces with colours that everyone gets these days … just a removable plastic brace with weird clips and springs.

I liked going to my appointments. The instruments neatly laid out on the bracket table, the glimpse of mysterious and shiny things in an opened drawer, my orthodontist calmly humming to himself as he tightened my brace (how did he know how much to bend the wires?).

I once asked “How do the teeth actually move?”. He peered from under his (impressively bushy) eyebrows and mumbled something into his mask about “the wires”, before returning to the brace tweaking. Fair enough, I thought, he’s clearly a busy man…I won’t push it.

Bone is not bony

If you’ve ever touched a “dead” bone from a skeleton, it feels hard, dry and brittle. But that’s not how bone is in the living body.

“Living” bone has blood vessels, cells and elastic fibres which you can see under a microscope.

The elastic fibres keep the bone springy. The cells remodel it throughout your life, nibbling away at bone here, laying it down there…so that your bone re-shapes gradually over time.

In older people, there are fewer cells and fibres, making bone more brittle which is why hip fractures in the elderly can heal very slowly. Children have much springier bone which heals much quicker.

Stick in the sand

When your orthodontist tightens your brace, a wire might press on a tooth from behind. This causes bone cells in front of the tooth to nibble away at the bone, and cells behind the tooth to produce bone. That allows the tooth to move forwards without becoming loose.

Imagine a stick in the sand on the a beach. To move the stick forwards through the sand without it falling over, you could scoop sand from in front, and then as you move the stick forwards, fill in sand behind it.

Gently does it

Your orthodontist has to be careful how much force is put on teeth. Gentle forces are best as they allow the teeth to move quickly, which for orthodontic treatment is 1mm a month. If we start pushing on teeth too hard, they won’t move at all.

So if you think your brace isn’t “tight enough”, don’t panic. We are probably just being very gentle…in this game, less is sometimes more!

Image courtesy of Stuart Miles / FreeDigitalPhotos.net