Oral And Maxillofacial Surgery, Oral medicine and radiology

What is Pericoronitis

Definition of Pericoronitis: It is defined as the inflammation of soft tissues covering the crown of the partially erupted or impacted tooth and is caused by Normal Oral flora or the inflammation of gingiva in relation to the crown of a partially erupted tooth most commonly seen in the Mandibular third molar regions (38 and 48)

Pericoronitis or Operculitis

Synonyms of Pericoronitis:

  1. Acute pericoronal infection
  2. Operculitis
  3. Folliculitis

Age: 17-24 years of age

History of Pericoronitis:

  • 1844 – Gunnel termed it “Painful affection”
  • End of 19th century – Painful affection changed to “Folliculitis” as the erupted tooth breaches the follicle.
  • 20th Century – Term “Pericoronitis”

Difference between Pericoronitis and Supracoronitis:

Pericoronitis is the inflammation of soft tissues covering the crown of the partially erupted or impacted tooth and is caused by Normal Oral flora.

Supracoronitis is the inflammation seen in the soft tissue covering tooth which are undergoing normal eruption, which is local inflammation and degradation of tissue which allows the eruption of tooth and inflammation is gone after eruption of tooth.

Differential Diagnosis:

  1. Trismus
  2. Tonsilitis
  3. Dentigerous Cyst
  4. Odontogenic Cysts
  5. Peridontitis

Predisposing or Causative Factors:

  • As we already read above the Normal Oral Flora are the causative organisms for Pericoronitis. Hence pericoronitis is caused mainly when the host defenses are compromised  ex: During minor illnesses like influenza, upper respiratory tract infection and severe fatigue. Thus we can see that even after impaction of teeth we do not see pericoronitis in all the cases, if the patient experiences a mild transient decrease in host defenses pericoronitis will occur.

Predisposing factor for pericoronitis

  • Minor trauma from Maxillary third molar – the operculum will be traumatized as it comes in between the upper and lower third molars which causes swelling and inflammation as it can get easily traumatized.
  • The operculum gets swollen and the upper third molar impinges on the tissue after the swelling has decreased and inflammation reoccurs which is a cycle of inflammation and decrease in infalmmation  which can be interupted only by extraction of the impacted third molar.
  • Entrapment of food under the operculum: During chewing there will be entrapment of a small amount of food under the opeculum which is very difficult to clean due to the lack of access in the corner of the mouth. Bacteria invade the impacted  food in the pocket under the operculum and the decay will lead to inflammation.

Causative Organisms:

  • Streptococci
  • Anaerobic Bacteria
  • And most normal oral flora


Pathogenesis is the explanation of the procedure in which Pericoronitis Starts and the complications caused due to it.  This is a flowchart which depicts the predisposing factors, clinical features and the complications caused due to pericoronitis.

perichoronitis pathogenesis
pericoronitis pathogenesis – ((Click on the image for zooming in))

Clinical Features:

Mild Pericoronitis: 

  • Localized Tissue Swelling and Redness
  • Soreness
  • Continuous dull pain
  • Localized Increase in temperature
  • Localized Enlargement of Lymph nodes

Acute Pericoronitis:

  • Caused due to trauma from the upper maxillary molar occlusion at the retromolar region.
  • Inflammation of the Operculum
  • Severe Redness, Soreness
  • Continuous severe localized pain
  • Localized intra oral swelling
  • Trismus
  • Pungent odor and halitosis
  • Tenderness and Enlargement of lymph node locally
  • Fever and Malaise
  • Leucocytosis
  • Dyspahgia, Pyrexia associated with tachycardia can be seen if neglected

pericoronitis - pericoronal pouch or operculum

Sub Acute Phase of Pericoronitis:

  • Intra Oral and Extra Oral Swelling is seen
  • Severe Trismus
  • Fever and Malaise
  • Severe Pain and tenderness in the retromolar region
  • Inflammation extends to the muscles of mastication
  • Halitosis
  • Dysphagia, Pyrexia and Tachycardia are severe
  • Ulceration of the Operculum is more prominently seen
  • Regional Lymphnode Tederness and Enlargement
  • Pericoronal Pus Discharge
  • Fascial Space infections of he mandibular Ramus and Lateral Neck

Chronic Pericoronitis:

  • Recurring inflammation and infection in the pericoronal region
  • Dull pain in the pericoronal region
  • Halitosis and bad taste in the oral cavity

Histologic Features:

Epithelium of the Operculum has:

  • Increased Vascularity
  • Hyperplasia
  • Intercellular edema
  • Leukocytic infiltration
  • Diffused infiltration of plasma cells
  • Diffused infiltration of lymphocytes

Management or Treatment of Pericoronitis:

Mandibular third molar should not be extracted until the signs and symptoms of pericoronitis have been completely resolved. As the incidence of Post operative complications like dry socket and post-op infection increase due to extraction during active infection.

Prevention of Pericoronitis:

  • Extraction of Impacted tooth
  • Operculectomy

Prevention of pericoronitis can be achieved only by removal of the impacted 3rd molar. Some dentists hace suggested removal of the soft tissue covering the tooth without removal of the impacted tooth which is called as “Operculectomy” which is very painful and usually does not succeed in removing the symptoms as it recurs immediately due to regrowth of the operculum .

Mild Pericoronitis:

  • Irrigation with Hydrogen Peroxide: H2O2 is used to mechanically debride the large periodontal pocket that exists under the operculum as it acts as a irrigating solution. Hydrogen Peroxide not only mchanically removes bacteria with its foaming action, it also reduces the number of anaerobic bacteria by releasing oxygen into the usually anaerobic environment of the oral cavity.
  • Other irrigating solutions: Chlorhexidine, Iodophors
  • Curettage is also adviced in case of mild pericoronitis by the dentist.

Sub Acute Pericoronitis:

  • Operculectomy
  • Extraction of the maxillary third molar opposing the affected tooth if not impacted
  • Local irrigation using Hydrogen peroxide or other irrigating solutions
  • Antibiotic regimen (Pencillin) should be started in case of Mild fever inflammation and swelling.

Patients who have had an episode of pericoronitis although managed successfully with antibiotic regimen will continue to have recurring episodes of pericoronitis, until the offending third molar has been extracted.

Patient should be admitted to the Hospital when we see the following symptoms:

  • Fascial Space infections of the mandibular Ramus and Lateral Neck
  • Trismus – inability to open mouth more  than 20mm
  • High Temperature > 110 F
  • Facial Swelling, Pain and Malaise



  2. are you talking about something around the crown of the tooth or something around between the tooth and its periodontal ligament?

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