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Oral & Dental Health

Acute Periapical Abscess (Dental Abscess)

A localized collection of pus at the apex (tip) of the tooth root, typically resulting from infection spreading from necrotic dental pulp (sequel to caries/pulpitis) or trauma.

Also known as: Dental Abscess, Tooth Abscess

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Referral and warning signs

When to refer

Refer ALL cases of suspected dental abscess to dental personnel (HC4+) for drainage and definitive management (root canal or extraction). URGENT referral needed if signs of spreading infection (facial cellulitis, trismus, difficulty swallowing/breathing), systemic illness, or suspected complications.

Red flags

  • Significant facial swelling (especially crossing midline or involving eye/neck).
  • Difficulty breathing or swallowing.
  • Trismus (difficulty opening mouth).
  • High fever / Signs of sepsis.
  • Altered mental status.
  • Proptosis or visual changes.

Signs and symptoms

  • Severe, constant, throbbing toothache.
  • Pain often worse on biting or pressure.
  • Tooth feels 'high' or 'raised'.
  • Affected tooth is tender to percussion (tapping), often exquisitely.
  • Tooth may be mobile.
  • Localized swelling of the gum (gingiva) near the root apex (parulis or 'gum boil').
  • Facial swelling (may extend to cheek, eye, neck depending on tooth location).
  • Fever, malaise, headache (if systemic involvement/cellulitis).
  • Difficulty opening mouth (trismus) if posterior teeth involved.
  • Regional lymph node enlargement and tenderness.
  • Pus discharge (intraorally via fistula/sinus tract, or extraorally if abscess points externally).

Risk factors

  • Untreated dental caries.
  • Untreated pulpitis / Pulp necrosis.
  • Failed root canal treatment.
  • Trauma leading to pulp necrosis.
  • Cracked tooth.
  • Severe periodontal disease extending to apex (less common).

Diagnosis

Clinical assessment

Based on history of severe toothache and clinical findings: localized tenderness, swelling (gingival or facial), tooth mobility/tenderness to percussion. Presence of pus discharge or fistula is confirmatory.

Investigations

  • Dental examination (check vitality, percussion).
  • Dental X-rays (Periapical): Shows radiolucency (dark area) at the root apex, may show associated deep caries/filling.
  • Consider FBC if systemic signs present.
  • Culture and sensitivity of pus (if drained).

Diagnostic criteria

Clinical signs of localized infection associated with a non-vital or severely compromised tooth +/- radiographic evidence of periapical radiolucency +/- drainage of pus.

Differential diagnosis

  • Periodontal abscess (usually associated with deep pocket, tooth often vital).
  • Pericoronitis (around partially erupted wisdom tooth).
  • Cellulitis from other source (skin, sinus).
  • Salivary gland infection.
  • Cyst or tumour.
  • Osteomyelitis.

Management

Non-pharmacological management

  • Drainage (Essential):
  • - Establish drainage through the tooth (opening pulp chamber - start of root canal) OR
  • - Incision and drainage (I&D) of fluctuant gingival or facial swelling (requires local anaesthesia). (LOC: HC4+)
  • Definitive Treatment of Source:
  • - Root Canal Therapy (Endodontics) OR
  • - Extraction of the causative tooth. (LOC: HC4+)

Pharmacological treatment

  • Pain Relief: Paracetamol and/or Ibuprofen (or other NSAID like Diclofenac). Opioids may be needed for severe pain initially. (LOC: HC2+)
  • Antibiotics: Indicated ONLY if signs of systemic involvement (fever, malaise) OR spreading infection (cellulitis, significant facial swelling, lymphadenopathy). NOT needed for well-localized abscess without systemic signs once drainage established.
  • - If indicated: Amoxicillin 500mg PO Q8H (Child: 25mg/kg Q8H) PLUS Metronidazole 400mg PO Q8H (Child: 10-12.5mg/kg Q8H) for 5-7 days. (LOC: HC4 when indicated)

Monitoring

Monitor resolution of pain, swelling, fever. Follow up for definitive dental treatment (root canal/extraction).

Complications

  • Cellulitis (spread of infection to facial/neck tissues).
  • Ludwig's angina (severe cellulitis of floor of mouth -> airway risk).
  • Cavernous sinus thrombosis (spread from maxillary teeth).
  • Osteomyelitis (bone infection).
  • Sepsis.
  • Airway compromise (from swelling).

Prevention

  • Prevention and timely treatment of dental caries and pulpitis.
  • Regular dental check-ups.

Patient education

  • Explanation of abscess as infection from tooth.
  • Need for drainage and definitive treatment (root canal/extraction).
  • Importance of antibiotics IF prescribed (due to spread/systemic signs).
  • Pain relief measures.
  • Signs of worsening/complications requiring immediate return.
  • Importance of follow-up and completing treatment.

Uganda-specific notes

Very common cause of emergency dental visits. Drainage (I&D or opening tooth) + extraction is common management due to limited endodontic access. Antibiotics often over-prescribed; should be reserved for spreading infection/systemic signs.

References

  • Uganda Clinical Guidelines (UCG) 2023

    Chapter 23, Section 23.2.4

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