When a child's top front teeth stick out well past the bottom ones because the lower jaw sits too far back, a Herbst appliance is one of the tools that may be suggested. It is fixed to the back teeth and holds the lower jaw slightly forward around the clock, so it keeps working without the child having to remember to put anything in. How much it achieves depends heavily on when it is used, which is why timing gets most of the attention in planning.
It works best while the jaw is still growing
A Herbst appliance is a type of functional appliance, designed to make use of a child's natural growth. A 2006 systematic review of functional appliances by Cozza and colleagues in the American Journal of Orthodontics and Dentofacial Orthopedics found that extra lower jaw growth was noticeably larger when treatment was carried out at the pubertal peak in skeletal growth. Of the appliances studied, the Herbst showed the highest rate of change per month.
In a child who has not yet reached that growth spurt, or in an adult who has finished growing, the effect on the jaw itself is much smaller. That is why a developing overbite is worth having checked during the primary school years, even if treatment is not due to start for a while. A dentist can monitor growth and the bite, then plan the right window.
How the appliance holds the jaw forward
The Herbst has metal frameworks or bands cemented to the upper and lower back teeth, joined on each side by a small telescopic arm, a little like a piston. The arms let the mouth open and close but stop the lower jaw from sliding back into its old position. Over the treatment period, the gap between the upper and lower front teeth (the overjet) reduces.
Some of that correction comes from the lower jaw, and a good deal comes from the teeth moving within the jaws: the lower teeth tend to move forward and the upper teeth backward. Families sometimes expect the appliance to reshape the jaw dramatically. The skeletal change is real but usually modest, and results differ from child to child.
What the evidence says about treating an overbite
A 2018 Cochrane review (Batista and colleagues) looked at treatment for prominent upper front teeth in children and adolescents. It found low-quality evidence that functional appliances used in adolescence reduce how far the upper front teeth stick out compared with no treatment. Starting treatment earlier, before adolescence, mainly helped by reducing the chance of the front teeth being injured, with no other clear advantage over waiting. The review analysed fixed and removable functional appliances as groups, so it does not single out the Herbst as better or worse than others.
Living with a Herbst appliance
The first week or two are the hardest. Cheeks rub on the new metal, the jaw can ache from its new position, chewing feels awkward and speech may sound slightly different. Most children settle into it, and orthodontic wax helps with any rubbing spots.
Because nothing comes out, the appliance cannot be forgotten in a lunchbox, but it does need care. Hard and sticky foods can bend the arms or loosen the bands, so foods like toffee, ice and hard crusts are best avoided or cut up. Plaque collects around the bands, so brushing slowly around every part of the appliance, and cleaning between the teeth, matters for the whole treatment. Regular reviews let the dentist check the fit and make adjustments.
The Herbst phase usually lasts a matter of months rather than years, and your dentist will give an estimate based on the bite. It is commonly the first part of a two-stage plan, with braces or aligners afterwards to line the teeth up. Our guide to what to expect with braces explains the second stage.
Fixed or removable
A twin block is a removable functional appliance that works on a similar principle. It can be taken out for eating and cleaning, but it only works when it is worn, and wear time can be difficult for some children to keep up. The Herbst removes that problem by being fixed, at the cost of being harder to keep clean and needing more care with food. Neither is simply better; the choice depends on the bite, the child's age and growth, and how well a removable appliance is likely to be worn. Our article on twin block appliances covers that option.
Functional appliances are not a replacement for jaw surgery in an adult with a severe skeletal difference. Adults with a significant overbite are usually offered other approaches.
What families ask about the Herbst
Does it hurt?
Expect tenderness and some rubbing for the first week or two, similar to new braces. After that it is usually comfortable, though a loose band or bent arm should be checked promptly.
Can my child play sport with it?
Usually yes, with a mouthguard suited to orthodontic appliances. Ask your dentist which type fits around the appliance.
What does it cost?
The Herbst is usually priced as part of a full orthodontic plan, which depends on whether braces or aligners follow, so a written treatment plan with fees after assessment is the most reliable guide. See our current deals page for any offers.
Having your child's bite checked
Lumi Dental provides orthodontic treatment with fixed braces and clear aligners. Our dentists are general dentists, and more complex bite problems may be referred to a registered orthodontist. If your child has a developing overbite, our team in Melrose Park can assess the bite, discuss timing and explain the options. Our guides to overbite, underbite and crossbite and early orthodontic treatment for children are useful reading before an appointment.
