Orthodontics

Orthodontics — Braces, Aligners and the Parts That Move a Tooth

Teeth move when a light, constant force is held against them long enough for the bone around the root to remodel. Everything in this category exists to apply that force and steer it: an appliance fixed to the teeth or worn over them, a wire or a tray that stores the force, and the small parts that hold it all together and adjust it visit by visit. What changes between cases is how the force is delivered — bonded metal and wire, or a sequence of clear trays — and this page lays out the parts of each.

Two ways to move a tooth

Brackets, tubes and the bond that holds them

A fixed appliance starts with an attachment on every tooth. Brackets are bonded to the front teeth in metal, ceramic or self-ligating form, and the back molars carry a OrthoMetric Bondable Molar Tube or a cemented band. A kit such as the ET Dental MBT 022 Mini Brackets Kit gives the prescription — the built-in tip and torque — while the bracket’s slot receives the wire.

The adhesive underneath

None of it stays on without the bond. Enamel is etched, primed and the bracket seated in a light-cure resin that is set with a curing light, giving the operator time to position each bracket exactly before it locks. The Anabond Orthofix Light Cure Adhesive Kit is a full bonding system for that step.

Archwires — where the movement comes from

The wire is the engine. A springy nickel-titanium wire is placed first — it takes up the curve of crooked teeth and pulls them toward the arch as it tries to straighten. Later stages step up to stiffer stainless-steel and beta-titanium wires that close spaces and set torque. The UU Ortho Super Elastic NiTi Archwires cover that first aligning stage.

Ligatures, elastics and chains

The wire has to be tied into each bracket, and that is the job of the small elastic or wire ties changed at every visit. Preformed steel ligatures like the UU Ortho Preformed Ligature Wire lock the wire down, while elastic O-rings and power chain add colour and pull teeth together.

Space closure and traction

Beyond tying the wire, elastics do active work. A stretched OrthoMetric Power Chain (E-Chains) drags teeth along the wire to shut a gap, and intermaxillary elastics run from the upper arch to the lower to correct how the jaws bite together.

Clear aligners — the removable route

For milder crowding and spacing, a series of transparent trays moves the teeth in small steps, each worn about two weeks before the next. Clinics that make their own trays thermoform them over printed models from sheets such as the UU Ortho TriAlign Pro Aligner Sheets.

The pliers that adjust it all

Fixed treatment is hands-on at every visit — bending wire, placing stops, seating bands, removing brackets. A plier like the Waldent How Pliers holds wire and auxiliaries where the fingers cannot, and sits alongside cutters, band seaters and debonding pliers on the bracket tray.

The sequence across a case

• Bonding brackets and molar tubes at the start of fixed treatment
• Etching, priming and light-curing the adhesive under each bracket
• Placing a light NiTi wire to level and align crowded teeth
• Tying the wire in with elastic or steel ligatures at every adjustment
• Stepping up to stainless-steel wire for space closure and finishing
• Running power chain and elastics to close gaps and correct the bite
• Thermoforming or fitting clear aligners for suitable cases
• Bonding a retainer or fitting a removable one once the braces come off

Matching the appliance to the case

1. Slot size — 0.018″ or 0.022″ — the 0.022″ slot takes heavier finishing wires and is the common all-rounder; 0.018″ gives finer control at light force. Pick one system and stay in it, because wires are sized to the slot.
2. Bracket material — metal is the durable, low-friction default; ceramic is discreet for adults but more brittle; self-ligating brackets drop the ligature step and cut chair time.
3. Wire by stage — springy NiTi for early alignment, stiffer stainless steel for closing and finishing, beta-titanium in between for torque; match the wire to where the case is, not to habit.
4. Band or bonded tube on the molar — a cemented band resists heavy occlusal load and suits banded auxiliaries; a bonded tube skips the separation visit and suits tight contacts.
5. Fixed or aligner — fixed braces handle complex movements and severe cases; aligners suit mild-to-moderate crowding and spacing where the patient will wear them the full day.

Who makes what here

Brackets, tubes and archwires run from OrthoMetric, ET Dental, UU Ortho and Penta Orthodontics across metal and self-ligating systems. Elastomerics, ligatures and power chain come from OrthoMetric and UU Ortho, with aligner sheets and retainer wire from the U Ortho lines and bonding adhesive from Anabond.

Pliers, cutters and the wider instrument tray are led by Waldent, which also supplies band seaters, bite blocks and debonding pliers, so a practice can equip both the bonding appointment and the adjustment chair from one category.

Keeping a case supplied to the finish

Orthodontic treatment is a long run of short appointments, and one missing consumable — a wire size, a chain colour, the adhesive for a rebond — is enough to postpone a visit. Ordering the brackets, wires, ligatures, elastics, adhesive and aligner stock from a single category means the next item a case needs is already on hand, so no patient slips off their adjustment schedule between bond-up and retention.

How do braces actually move teeth?

They apply a light, continuous force through the archwire and elastics. That pressure signals the bone on one side of the root to dissolve and the bone on the other side to rebuild, so the tooth drifts through the jaw and the new position becomes stable. The force has to stay gentle and constant — too much simply hurts and can damage the root rather than speed things up.

Why does the wire get changed so many times during treatment?

Because each stage needs a different wire. Treatment starts with a thin, springy NiTi wire that can flex into badly aligned brackets and coax them into line. As the teeth straighten, the operator moves up to thicker and stiffer wires that no longer bend to the teeth but instead impose a precise arch shape, close spaces and set the final tip and torque. One wire cannot do both jobs.

Metal braces or clear aligners — which suits a case?

It depends on the movement required and the patient’s discipline. Fixed metal braces handle the full range, including rotations, big space closures and bite correction, and work regardless of patient effort. Clear aligners suit milder crowding and spacing and are far less visible, but only work if worn around twenty-two hours a day. Complex cases are usually faster and more predictable on fixed appliances.

What is the difference between a molar band and a bonded tube?

Both give the back molar its attachment, but a band is a steel ring cemented right around the tooth, while a tube is bonded flat onto the outer surface. A band grips hard under heavy chewing load and carries banded auxiliaries like expanders, but needs a separation appointment first. A bonded tube is quicker to place and kinder to tight contacts, though it debonds more readily than a band lets go.

Do teeth stay straight once the braces come off?

Only with retention. Teeth have a strong tendency to drift back toward where they started in the months after treatment, so a retainer holds them while the bone and gum fibres settle. That may be a thin wire bonded behind the front teeth, a removable clear retainer worn at night, or both. Retention is effectively lifelong if the result is to be kept.