Reverse pull facemask: early underbite (Class III) treatment for growing children

Key facts

• External appliance worn at home, often evenings and overnight
• Pulls the upper jaw forward in growing children with an underbite
• Works best around ages 6 to 10
• Often combined with a palatal expander
• Growth is monitored until the teenage years end

Understanding Class III and underbite

Orthodontists call it a Class III relationship when the lower jaw and teeth sit forward relative to the upper jaw. Signs include an underbite, where the lower front teeth bite in front of the upper teeth, front teeth that meet edge-to-edge, a concave or 'dished' profile and a flat midface. The cause can be a lower jaw that is large, an upper jaw that is small or set back, or a combination. Some children have a functional shift, where the jaw slides forward to bite. Working out which pattern is present matters, because a facemask aims to influence the upper jaw and is most useful when upper-jaw deficiency is part of the problem.

How the facemask works

The facemask rests on the forehead and chin with a crossbar in front of the mouth. Elastics run from the crossbar to hooks on an appliance fixed inside the mouth, usually a palatal expander bonded to the upper teeth, or in selected cases to miniscrew anchorage. The elastics apply a gentle forward pull on the upper jaw. In growing children, the sutures around the upper jaw are still active, so this force can encourage the upper jaw to develop further forward and can improve the bite and profile. In adults the same correction usually needs jaw surgery, which is why timing in childhood is so important.

The ideal age: why 6 to 10 matters

The facemask works best early, typically between about six and ten years of age, when the sutures of the upper jaw respond most readily. Results tend to be less predictable as the child gets older, although some older children may still benefit. Because of this, an orthodontic check around age seven is valuable, especially if a parent or sibling has an underbite, as Class III patterns can run in families. Dr. Pacha confirms diagnosis and growth stage with a clinical examination, scans and X-rays before recommending a facemask, and explains the likely benefits and limits honestly so families can make an informed choice.

Hours of wear and combining it with expansion

The facemask is worn at home, usually in the evening and overnight, for the number of hours prescribed — commonly many hours a day — and not at school. Consistent wear is essential, because the effect depends on steady force over months. Expansion is often combined with protraction: the expander widens a narrow upper jaw, corrects any crossbite, and provides a solid anchor for the elastics. Some plans alternate expansion and constriction to mobilise the sutures. Children usually adapt within a week or two; mild pressure on the teeth and chin is normal. Skin on the chin and forehead should be kept clean and dry to avoid irritation.

Results, follow-up and the long-term view

Many children show improvement in the bite and profile over several months of consistent wear, but outcomes vary, and the active phase is typically followed by a holding phase. Because the lower jaw can continue to grow forward through the teenage years, Class III patterns need monitoring until growth is complete. Some children need further orthodontic treatment, braces or, in a minority of cases with strong lower-jaw growth, jaw surgery in adulthood; early treatment may reduce the chance of surgery but cannot rule it out. Contact the clinic if the intraoral appliance loosens, elastics cause sore spots, or the facemask breaks, so wear is not interrupted.

An orthodontic check around age seven can identify crossbites, narrow jaws, habits and crowding while the jaws are still growing. Some problems are easier to correct at this stage; others are simply monitored.

Prepared by the Manhal Medical Center editorial team · Updated: 2026-10-18 · Treating specialist: Dr. Moaiyad Pacha

This page is general information and does not replace a consultation. Suitability, risks and results vary between patients.