What are the Causes & Risk Factors of Pericoronitis?:

The most common site of
pericoronitis is impacted or partially erupted lower 3rd

The most common cause behind
peri-coronal inflammation is the entrapment of
plaque and food debris between tooth crown and overlying
operculum (gum flap).  
This is an ideal area for the growth of bacteria and it is difficult to keep clean; also,
there is the constant possibility of acute inflammation of
peri-coronal (around the
crown of the tooth) sites.  It may be due to trauma, occlusion or entrapment of
foreign body below the
peri-coronal flap / operculum.

Risk Factors:

•        Presence of unerupted / partially erupted tooth / teeth in communication with
       the oral cavity.  Lower 3rd molars (which are
vertically and disto-angularly
impacted) are most commonly affected
•        Presence of
periodontal pocket adjacent to unerupted / partially erupted
•        Opposing tooth / teeth in relation to
peri-coronal tissues surrounding
        unerupted / partially erupted tooth / teeth
•        Previous history of
•        Poor oral hygiene
•        Respiratory tract infections & tonsillitis
•        Age (20 - 29 year age group; the condition was rarely seen before 20 or
       after 40).
•        Emotional stress
Last Updated 28th September 2018
Photos of Pericoronits / Operculitis effecting Lower Jaw Wisdom Teeth
Pathogenesis of Pericoronitis
Pericoronitis is inflammation in the soft tissues (such
as the
gingiva and dental follicle) surrounding the
crown of a partially erupted tooth, usually the lower
3rd molar (wisdom tooth).

It generally does not arise in teeth that erupt normally;
usually, it is seen in teeth that erupt very slowly or become
impacted and it most commonly affects the lower 3rd

Once the
follicle of the tooth communicates with the oral
cavity, it is thought that bacterial infiltration into the
follicular space initiates the infection.

The soft tissue covering over a partially erupted tooth is
known as
peri-coronal flap or gingival operculum.  
Maintenance of oral hygiene in such area can be very
difficult to achieve by normal methods of oral hygiene.

There was no significant difference between the sexes.

A seasonal variation is noted with peak incidences
occurring in June and December.

Bilateral (both sides)
pericoronitis is rare and suggests
infectious mononucleosis (Glandular Fever).
According to the International Classification of Diseases, pericoronitis can be
classified as an
acute and chronic pericoronitis.


Acute pericoronitis is of sudden onset, short lived but having significant symptoms,
such as varying degrees of inflammatory involvement of the
pericoronal flap. There
is also a presence of systemic involvement. Usually, the
acute form of pericoronitis
is seen in the patients having poor oral hygiene.

Acute Pericoronitis – Clinical Features

•        Caused 2nd to occlusal trauma from maxillary (upper) 3rd molar on
        retro-molar region (area behind the lower wisdom tooth)
Operculitis (Inflammation of the operculum)
•        Severe redness + soreness
•        Continuous severe pain
•        Localised intra-oral swelling
Trismus (limited mouth opening)
Fœtor ex ora (bad breath)
Lymphadenitis ++
Pyrexia (fever) & malaise
•        Dysphagia (problems eating)
Pyrexia (fever) associated with tachycardia (increased heart rate) if

Sub-Acute Phase of Pericoronitis – Clinical Features

•        Intra- & Extra-oral swelling
•        Severe
•        Pyrexia & malaise
•        Fœtor ex ora
•        Severe pain in retro-molar region
•        Inflammation of
masticatory muscles (chewing muscles)
Dysphagia, pyrexia & tachycardia are severe
Operculum ulceration
Lymphadenitis +++
Peri-coronal pus ++
Fascial space infections of neck & mandible (Ludwig’s Angina, Para-
pharyngeal abscess)


Pericoronitis may also be classified as chronic / recurrent.  Acute pericoronitis
occur repeatedly and periodically.  It may cause few symptoms but some signs are
visible at the time of intra-oral examination.  The
chronic type mostly seen with
good-moderate oral hygiene.

The main complaint is of a dull pain or mild discomfort lasting a day or two, with
remission lasting many months.  
Cacogeusia (bad taste) may also be present.  
Pregnancy and fatigue are associated with an increased occurrence of

Chronic Pericoronitis – Clinical Features

•        Localised tissue swelling & redness
•        Soreness
•        Continuous dull pain
•        Localised rise in temperature
Lymphadenitis +

These include debridement of plaque and food debris, drainage of pus, irrigation
with sterile saline,
chlorhexidine or hydrogen peroxide & elimination of occlusal

In the past the use of caustic agents such as
chromic acid, phenol liquefactum,
glacial trichloroacetic acid or Howe’s ammoniacal solution was advocated to
control pain by placing a small amount on a cotton pledget under the

The resultant
chemical cauterisation of the pain nerve endings in the superficial
tissues gave rapid pain relief; however, the use of these toxic chemicals in the oral
cavity is no longer encouraged.

Ozone has been put forward as a local antimicrobial that might be a useful adjunct
in the treatment of
pericoronitis; however, there is no research available to show
its efficacy as yet.

In addition to local pain and swelling, if the patient is exhibiting regional or systemic
signs and symptoms, antimicrobial therapy (such as
metronidazole) is
recommended; however, it should be emphasised that it is as an adjunct rather
than a 1st line treatment.  These are all active against anærobic bacteria, which
are the predominant microflora found in

Once the
acute phase of the pericoronitis has passed, operculectomy has been
used as a preventive measure.