Ortho Appliances - Quad Helix

A quad helix is an orthodontic appliance that is used for the upper teeth. It is attached to the molars by two bands and contains two or four active helix springs. The springs widen the arch of the mouth with the goal of creating additional room for crowded teeth or to correct a posterior cross-bite. A posterior cross-bite occurs when the lower teeth are outside the upper teeth. The quad helix is typically made from a 38 mil stainless steel wire. The appliance is inserted into attachments which are then welded onto the bands. This gives the orthodontist the ability to adjust the appliance without entirely removing the bands.

Prior to the introduction of the quad helix, the coffin spring was used. Similar devices such as the tri-helices and bi-helices were also used.

The quad helix expander works by slowly pushing the teeth out which eventually widens the upper arch. A quad helix expander is typically used for patients who have a narrow top jaw, a cross bite and/or crowded teeth.

The quad helix can be constructed as a fixed or a removable appliance. It works by widening the arch form with the assistance of helixes which are bent at the four corners of the appliance and lingual wires. The quad helix appliances are bent from straight wire allows customization of the vault while maintaining the integrity of the wire. The device is commonly used for the following situations: cross bites that need expansion, mild expansion for mixed dentition cases, Class III cases which need expansion, Class II cases and patients with a cleft palate. A tongue crib and facemask hooks can also be incorporated into the design, if needed.

Treatment & Care

There are two different methods used to activate the quad helix prior to placing it in the mouth. In 1979 it was suggested to activate the appliance with a three-pronged pliers which incorporated expansion and molar-rotating force. Another method which was suggested in 1995 uses an arch form which is chosen from a pentamorphic chart and serves as a pattern to regulate the quad helix.

The appliance should be cleaned twice daily with toothpaste and a soft toothbrush. It is important for patients to thoroughly clean around the appliance, gums, teeth and bands in order to maintain proper hygiene and prevent inflammation.

Care at Home

• Take over-the-counter pain medication, as needed
• During the first week or two, moderate sensitivity and pressure is normal. Contact the orthodontist if excessive pain or swelling occurs
• Avoid hard, sticky and sweet foods which can damage the appliance
• It is critical to keep the quad helix clean. A water-pik and frequent mouth rinsing can be helpful in addition to regular brushing

Common Concerns

• It can take some time to get used to a quad helix. The tongue may get irritated or feel swollen at first
• You may feel as though they cannot swallow. With some practice, you will get used to swallowing without any issues
• Your teeth may feel uncomfortable. This can be especially noticeable on the outside of the back teeth
• Speech may be challenging and you may have a slight lisp during your first few days with the appliance. With practice, you will learn to articulate around the appliance