Exposing an impacted tooth for orthodontics

What an impacted canine is

The canines are the corner teeth, sometimes called eye teeth. The upper canines usually come through at around 11 to 13 years of age. Sometimes one or both develop in the wrong position and stay under the gum, held in the bone. This is called impaction. After the wisdom teeth, the upper canines are the teeth most often impacted.

An impacted upper canine most often lies in the roof of the mouth, the palate, behind the front teeth. Less often it lies on the lip side. The baby canine is frequently still in place.

How it is found

During childhood check-ups, the dentist feels the gum above the baby canines. By about 10 or 11, a canine on its way down can usually be felt there as a small bump. When it cannot, or when the two sides differ, X-rays taken from two angles show where the tooth lies. A small three-dimensional scan is sometimes added. Regular check-ups in childhood are described in children's teeth.

The options

Which option suits a particular person depends on where the tooth lies, their age, the space available and whether they are willing to wear a fixed brace. The main options are:

• Removing the baby canine, in selected children whose permanent canine is not far out of place. This sometimes lets the canine find a better path;
• Exposure and orthodontic alignment: the tooth is uncovered in a small operation and brought into place with a fixed brace. This is the subject of this page;
• Leaving the tooth where it is, if it is causing no problems, and checking it on an X-ray from time to time;
• Removing the buried tooth, for example when it lies too far away to be moved or the person does not want a brace. Moving the tooth into its place in one operation, called transplantation, is considered only occasionally.

A plan shared by orthodontist and dentist

Exposure is one step within orthodontic treatment, planned together by the orthodontist and the dentist who carries out the operation. Often a fixed brace is fitted beforehand to make room for the canine; sometimes other teeth are removed to create that room. The dentist then uncovers the tooth, and the orthodontist uses the brace to guide it gradually into the space.

Moving an impacted canine is slow. The treatment needs a mouth that is otherwise healthy, and a patient willing to wear the brace and keep it clean for as long as it takes.

How the tooth is uncovered

There are two broad approaches. The choice depends mainly on how deep the tooth lies and on which side of the arch.

• Closed exposure. When the tooth is deeply buried, the gum is lifted, a small bracket with a fine gold chain is bonded to the crown, and the gum is stitched back over the tooth. Only the end of the chain comes through the gum, where the orthodontist can later connect it to the brace.
• Open exposure. When the tooth lies nearer the surface, a small window of gum, and sometimes a little bone, is removed over the crown so that the tooth stays uncovered. A gauze pack soaked in antiseptic, or a small plastic plate, may cover the area while it heals. On the lip side, the gum can instead be moved higher and stitched so that the crown is left showing.

Research has not shown either approach to be clearly better; the dentist and orthodontist choose the one that suits the tooth.

Before, on the day and afterwards

1. Before. The X-rays or scan show how close the tooth lies to the roots of its neighbours. The dentist explains the plan, the anaesthetic and the risks, and the patient, or a parent for a child, gives consent.

2. Anaesthetic. Either a local anaesthetic, sometimes with sedation, or a general anaesthetic as a day case.

3. The operation. The gum over the tooth is opened and, if needed, a thin layer of bone is removed. The crown is cleaned, and either the bracket and chain are bonded on or the crown is left uncovered, as planned. The gum is repositioned and stitched.

4. Afterwards. Soreness, a little swelling and some bleeding are common at the start. The dentist gives written aftercare advice, which usually covers pain relief, soft food, gentle brushing and mouthwashes, and care not to catch the chain when eating. Stitches either dissolve or are removed at a review.

5. Guiding the tooth. Once the gum has settled, the orthodontist connects the chain to the brace and applies a light, steady pull. The tooth moves slowly, and the brace is adjusted at regular visits. The dentist or orthodontist explains what to expect along the way.

Risks

Soreness, swelling, bruising and some bleeding are common and usually settle as the area heals. Less often:

• the wound becomes infected and needs treatment;
• the bracket or chain comes loose, and a second small operation may be needed to reattach it;
• the roots of neighbouring teeth are damaged during the operation, or, rarely, lose some of their length;
• the canine is fused to the bone and does not move, and may then need to be removed.

Exposure gives a buried tooth the chance to be brought into place, and it cannot promise that the tooth will move. The chances depend on the position of the tooth and the age of the patient, and the orthodontist and dentist explain them for each case.

If the canine cannot be kept

If a buried canine is removed, or a baby canine that was kept is lost in adult life, the gap can often be closed with a brace, or filled with a bridge, a denture or an implant. The other teeth often impacted are the wisdom teeth. Cleaning around the brackets and wires of a brace is explained in cleaning your teeth.