What is an impacted tooth? Which impacted teeth are removed and which are monitored

Why do teeth stay impacted?

Lack of space in the jaw, a tooth developing at the wrong angle, a primary tooth falling out late, obstacles such as cysts or extra teeth, and genetic factors prevent eruption. With the shrinking of modern jaws there is usually not enough room for wisdom teeth; most of the population has at least one impacted wisdom tooth.

Types

• Fully impacted: Within bone, gum closed over it.
• Partially erupted: Part of the tooth is exposed in the mouth; food and bacteria collect under the gum flap — the type that causes the most trouble.
• Angle: Tilted forward (mesioangular, the commonest), vertical, horizontal, tilted backward.

Symptoms

Pain and pressure at the back of the jaw, swollen red gum (pericoronitis), difficulty opening the mouth, bad taste and odour, pain radiating to the ear and throat, decay and pain in the tooth in front. Many impacted teeth cause no symptoms for years and are noticed on a panoramic X-ray.

The decision to extract: when is it needed?

• Recurrent pericoronitis (infection of the gum flap)
• Decay, root resorption or bone loss in the tooth in front
• A cyst or tumour-like appearance around the tooth
• As part of an orthodontic plan (gaining space, preventing crowding)
• Prosthetic planning
• A partially erupted tooth whose own decay cannot be restored

Can be monitored: Teeth fully within bone, causing no symptoms and not affecting the neighbouring tooth, very close to the lower jaw nerve; followed with yearly X-rays. "Every wisdom tooth must be removed" is not true; but teeth expected to cause trouble heal more easily when removed young (18–25). More: When should wisdom teeth be removed?

Impacted canines

If an upper canine has not erupted by 11–13 and appears impacted on X-ray, it is usually not removed: the orthodontist exposes the tooth with a small surgical procedure, bonds a bracket and pulls the tooth into place over months. Early diagnosis (an examination and panoramic at 9–10) shortens the process. Extraction is considered only for teeth that cannot be brought in or that damage the neighbours. See Orthodontics for children: when?

Assessment

A panoramic X-ray shows the tooth's position, its relationship to the neighbouring teeth and its closeness to the nerve canal. If the root tip is near the nerve canal, a 3-D CBCT scan pinpoints the position; this sets the operative plan and the risk of altered sensation.

The operation

1. Local anaesthesia; sedation can be discussed for anxious patients.
2. The gum is opened, bone is removed if needed, and the tooth is sectioned and removed.
3. The site is irrigated and sutured. Duration 20–60 minutes.

Recovery

Swelling and pain peak in the first 2–3 days and largely settle within a week. Temporary limitation of mouth opening is normal. No smoking, straws or rinsing for the first 72 hours because of the dry-socket risk. Numbness of the lip and chin in the lower jaw is rare and usually resolves within weeks. Full aftercare list: Extractions and oral surgery.