Functional appliances
In some children the upper front teeth stick out well ahead of the lower teeth, often because the lower jaw sits further back. A functional appliance, such as a Twin Block, holds the lower jaw in a forward position while the child is growing. Over months, the teeth and jaws adapt, and the gap between the upper and lower front teeth (the overjet) reduces. It is most effective during the growth spurt, so timing matters. Braces usually follow to finish the alignment. At Suman Dental Care it is planned by Dr. Aashka Doshi, an orthodontist (MDS, orthodontics and dentofacial orthopaedics).
Step by step
- Before. The upper front teeth sit well ahead of the lower ones (a large overjet).
- Fit. An upper and a lower plate are fitted, each with a sloping block.
- Guide. Each time the mouth closes, the slopes guide the lower jaw forward, worn for months while the child grows.
- Result. The overjet reduces; braces usually follow to line up the teeth.
- 1Consultation and records
The orthodontist examines the bite and checks how much growth is left, using photographs, X-rays and impressions or a scan. If a wider X-ray is needed, you will be told where to have it taken.
- 2Make the appliance
A Twin Block is two plates, one upper and one lower, made to the model of the teeth. Each has a sloping block that meets the other when the mouth closes.
- 3Fit and practise
The plates are fitted. The slopes guide the lower jaw forward every time the teeth close. Your child practises putting them in, taking them out and speaking with them.
- 4Wear and review
The appliance is worn most of the day and night, often including meals once the child is used to it. Every 4–8 weeks the orthodontist checks the bite and adjusts or trims the blocks.
- 5Braces to finish
When the overjet has reduced, the appliance is usually worn for a further period to hold the new position. Braces then line up the teeth and settle the bite.
- A child whose upper front teeth stick out well ahead of the lower teeth (a large overjet)
- A lower jaw that sits further back than the upper jaw, in a child who is still growing
- Prominent upper front teeth at risk of injury in a fall or sport
- A child who can wear the appliance for most of the day, every day
- Adults: once growth has finished, the jaws no longer adapt this way, so braces, and sometimes jaw surgery, are discussed instead
The appliance feels bulky at first. Speech sounds different and the jaw can ache for the first week as the muscles get used to the forward position; both usually settle within one to two weeks.
Wear the appliance for the hours the orthodontist advises. Take it out to brush, clean it with a soft brush and cold water, and keep it in its case when it is out of the mouth. Avoid sticky and hard foods.
Call the clinic if the appliance breaks, stops fitting or rubs a sore spot.
- It only works when worn. Most of the change depends on how many hours a day the appliance is in.
- Growth varies: how much the jaws adapt differs between children, and some still need further treatment later.
- Jaw muscle ache and changed speech are common in the first weeks.
- Lost or broken appliances delay treatment.
- Decay and gum soreness can follow if teeth and the appliance are not cleaned well.
- The bite can partly relapse if retention is stopped too early.
What affects the cost
We don't publish prices online. After an examination you get a written estimate that lists each item.
Payment by card, cash or UPI.
Questions patients ask
Does a functional appliance make the lower jaw grow?
It holds the lower jaw forward while a child is growing, and the teeth and jaws adapt to that position. How much of the change comes from the jaw and how much from the teeth varies between children. Your orthodontist explains what to expect for your child.
Why does the timing matter?
These appliances work with growth, so they are most useful during the growth spurt. Too early can mean a long treatment, and too late can mean little effect. An orthodontic assessment helps choose the time.
Can my child eat with a Twin Block?
Many children wear it while eating once they are used to it, which helps it work. Your orthodontist will advise. Sticky and hard foods are avoided.
Will my child still need braces?
Usually yes. The functional appliance corrects the relationship between the jaws, and braces then line up the individual teeth and settle the bite.
Why fix prominent front teeth early?
Upper front teeth that stick out are more easily chipped or broken in a fall. Reducing the overjet can lower that risk, and some children also feel more comfortable with how their teeth look.
Questions about this treatment?
Send a WhatsApp message or book an examination. The dentist explains the options before anything starts.