How do braces work?

Page updated October 14, 2026. Medically reviewed by Dr. Abraham Thomas and Dr. Jennifer Loucks-Buren.

Braces work by putting gentle, constant pressure on your teeth. That pressure doesn't push teeth through bone like a nail through wood; it sets off a slow cycle in which bone is removed on one side of each tooth and rebuilt on the other. The AAO sums up what makes treatment succeed in three words: pressure, time and cooperation (AAO).

The parts of braces

Self-ligating braces skip the ligatures and hold the wire with a built-in clip or door instead (AAO); see Damon braces. More on the extras: power chains, rubber bands and spacers.

How teeth actually move

Each tooth sits in the jawbone, attached by the periodontal ligament, a thin layer of tissue between the root and the bone (Current Osteoporosis Reports review). When braces press on a tooth, one side of that ligament is squeezed (the "compression side") and the other is stretched (the "tension side"). A 2023 review in Current Osteoporosis Reports describes what happens next (Current Osteoporosis Reports review):

1. The pressure makes fluid move through the bone around the tooth, which sets off a local inflammatory response.
2. On the compression side, cells called osteoclasts break down bone, making room for the tooth to move into.
3. On the tension side, cells called osteoblasts lay down new bone, filling in behind the tooth.
4. Bone cells called osteocytes sense the load and coordinate both processes.

The review notes that bone resorption by osteoclasts takes around 3 weeks, while rebuilding by osteoblasts takes around 3 to 4 months (Current Osteoporosis Reports review). It also says the ideal amount of force is still debated, but that both the mechanical response and inflammation are needed for teeth to move (Current Osteoporosis Reports review).

That inflammation has a practical side. Cleveland Clinic recommends acetaminophen for braces soreness and says NSAIDs such as ibuprofen are best avoided, because they block prostaglandins and can interrupt the tooth movement process (Cleveland Clinic). Ask your orthodontist which pain reliever to use.

Why it takes months, not days

Because bone has to be removed and rebuilt, teeth can only move so fast. Slight corrections can take a few months, while complex cases can take years; most people wear braces for 12 to 24 months (AAO). Cleveland Clinic gives an average of about 2 years, with some people finishing in under 12 months and others needing up to three years (Cleveland Clinic).

Adults often take a little longer, because adult teeth are more firmly set in the jaw (AAO). See how long braces take for the full timeline.

What happens at adjustments

To keep the teeth moving, the orthodontist adjusts the brackets and archwires over the course of treatment (AAO). Visits are every 4 to 12 weeks, depending on where you are in treatment (AAO); the AAO's guide to how braces work says many patients go every six to ten weeks (AAO). Self-ligating braces can allow longer gaps between visits (AAO).

Why braces feel sore

The pressure and the bone remodeling it triggers are why teeth feel tender after braces go on and after each adjustment. The AAO says discomfort is usually strongest in the first 24 to 48 hours (AAO). Cheeks, lips and tongue can also be irritated while they get used to the brackets (Cleveland Clinic). See do braces hurt for relief tips.

What braces can fix

Braces treat a wide range of problems. The AAO lists (AAO):

• Crooked or crowded teeth
• Bite problems: overbites, underbites and crossbites
• Teeth that are hard to brush and floss, or that make you bite your tongue or cheek
• Jaw discomfort or clicking, and problems chewing
• Missing or extra teeth, and adult teeth that arrive late

Problems with the jaw bones themselves can be beyond what moving teeth can fix; severe cases may need jaw surgery alongside braces (Cleveland Clinic).

How different types of braces work

All of them rely on the same biology. Aligners only work while they're in, so they need to be worn at least 22 hours a day (AAO). Compare prices in types of braces.

Appliances that help braces work

Other tools may be added to speed up treatment or improve the result: palatal expanders, temporary anchorage devices and rubber bands (AAO), and for some patients headgear (AAO). A palate expander widens the upper jaw (Cleveland Clinic), and elastics help with jaw alignment (AAO). See palate expanders and headgear.

Your part: pressure, time and cooperation

The AAO says braces need your cooperation as much as the orthodontist's skill (AAO):

• Keep teeth clean, and see your general dentist every 3 to 6 months (AAO)
• Avoid foods that can break brackets, and limit sugary drinks (AAO)
• Wear elastics exactly as prescribed (AAO)
• Never skip adjustment appointments (AAO)

Call promptly about a broken bracket or loose wire: the sooner it's repaired, the less likely it adds time (AAO). Our guide to taking care of braces covers the daily routine.

Why you need a retainer afterward

When the teeth reach their planned positions, the braces come off and you're usually fitted with a removable or permanent retainer (AAO). Without one, teeth can shift back (Cleveland Clinic). Compare the options in types of retainers and their prices in retainer cost.