Pericoronitis During Orthodontic Treatment

What is pericoronitis?

Pericoronitis is inflammation of the pericoronal tissues — the gum tissue surrounding a partially erupted tooth. The overlying gum flap, known as the operculum, creates a space that collects food debris and bacteria and is difficult to clean, creating ideal conditions for polymicrobial infection. Lower wisdom teeth (lower third molars) are by far the most commonly affected because they frequently erupt partially and remain partially covered by gum for months or years. The infection can range from mild local inflammation producing tenderness and bad taste, to severe infection with diffuse facial swelling, trismus (difficulty opening the mouth), fever, and systemic illness. Severe pericoronitis spreading into the fascial spaces of the neck is a dental emergency requiring hospital management.

Why braces increase pericoronitis risk

Orthodontic fixed braces significantly increase pericoronitis risk in patients with partially erupted wisdom teeth for several reasons. Plaque accumulation around brackets and wires is substantially greater than around natural teeth, and the debris accumulates throughout the arch including in the posterior region. Posterior brackets and molar bands — if present — create additional plaque traps close to the partially erupted wisdom tooth. Cleaning the distal aspect of the lower second molar is always difficult, but the presence of brackets and wires makes it considerably harder. The dietary changes associated with braces — softer foods and altered chewing patterns — may also cause food to collect differently. Patients with wisdom teeth beginning to erupt during brace treatment are at heightened risk throughout that period.

How pericoronitis presents during orthodontic treatment

Patients typically notice throbbing pain in the lower back of the mouth, often initially attributed to orthodontic soreness from a recent adjustment. The pain is usually worse on biting, on touching the area, and when swallowing. Bad taste and halitosis are common. Examination reveals a tender, swollen, red operculum over the wisdom tooth, often with pus expressible from beneath the flap. Trismus — reduced mouth opening — indicates spread of infection into the adjacent muscles and connective tissue. Cervical lymphadenopathy and systemic features (fever, malaise) indicate a more serious infection requiring urgent assessment. Orthodontic patients who cannot attend their usual orthodontist should access an NHS urgent dental care service.

Acute management of pericoronitis

First-line management involves irrigation of the pericoronal space under the operculum to remove debris and bacteria. This is performed with a blunt-ended irrigating syringe using warm saline or chlorhexidine solution. Patients are instructed in home irrigation between clinical visits. Oral hygiene instruction specific to the wisdom tooth area is reinforced. Antibiotics are prescribed when there is evidence of spreading infection, systemic involvement, trismus, or failure to respond to local measures alone. Metronidazole is the antibiotic of choice for pericoronitis because of its efficacy against anaerobic organisms; amoxicillin is added when broader coverage is needed. Operculectomy — surgical removal of the gum flap over the tooth — is an option where recurrent episodes occur and the wisdom tooth has sufficient eruption to be worth retaining, though in practice extraction is usually the more definitive solution for lower third molars.

Should orthodontic appointments continue during active pericoronitis?

Orthodontic adjustment appointments should be deferred during an acute episode of pericoronitis with systemic features — fever, trismus, or facial swelling. There is little clinical benefit in attempting archwire changes or adjustments when the patient is in pain, cannot open adequately, and may be on antibiotics. Once the acute infection has resolved — typically within five to ten days of starting antibiotics and irrigation — orthodontic appointments can resume. Mild pericoronitis without systemic involvement does not necessarily require cancellation but the wisdom tooth area should be professionally irrigated at the appointment and oral hygiene reinforced. The orthodontist should document the episode and discuss its implications for wisdom tooth planning.

Wisdom tooth extraction timing relative to orthodontic treatment

A single episode of pericoronitis is a clear indication to reconsider the long-term management of the wisdom tooth. Lower third molars that have caused pericoronitis are commonly recommended for extraction, because recurrence is frequent — studies suggest that up to 60% of patients will have a second episode within a year. For patients in the middle of orthodontic treatment, the timing of extraction matters. Ideally, an uncomplicated lower wisdom tooth extraction can be undertaken during active treatment without disrupting orthodontic mechanics, provided good soft tissue healing is given time before the next heavy activation. In some cases, orthodontists will proactively recommend extraction of lower third molars at the start of treatment — particularly in crowded cases where the wisdom tooth's position could contribute to relapse of the lower incisors — thereby preventing pericoronitis arising during treatment.

Prevention during orthodontic treatment

Patients with partially erupted wisdom teeth beginning brace treatment should be counselled specifically about pericoronitis risk. A soft-bristled brush angled distally past the lower second molar bracket, a Tet-range interdental brush in the space behind the last bracket, and a water flosser directed under the operculum are all useful adjuncts. Warm saline rinses are a simple and effective method of keeping the pericoronal crevice clean. Chlorhexidine mouthwash used periodically — not indefinitely because it stains — is appropriate during high-risk periods such as increased eruption activity. Regular hygiene appointments with professional cleaning around the wisdom tooth region are more valuable in brace patients than in the general population.

Useful related pages

This guide is for general information only. It is not a diagnosis, treatment plan, or substitute for advice from a registered dentist or orthodontist.