What is the differential diagnosis for acute gum pain in a patient without evidence of abscess or infection?

Differential Diagnosis for Acute Gum Pain Without Abscess or Infection

The most common non-infectious causes of acute gum pain are temporomandibular disorders (TMD), traumatic injuries, neuropathic pain conditions (including post-traumatic trigeminal pain and atypical odontalgia), and acute periodontal lesions such as necrotizing periodontal disease or pericoronitis. 1, 2

Primary Non-Infectious Causes

Temporomandibular Disorders (TMD)

• TMD represents the leading non-dental, non-infectious etiology, affecting 5-12% of the population with peak incidence at ages 20-40 years, predominantly in females. 2
• TMD encompasses muscle pain involving the muscles of mastication, disc displacement with or without limitation in opening, and joint pathology that can coexist in the same patient. 1
• Pain may be unilateral or bilateral, continuous or episodic, and is often associated with comorbid conditions including back pain, fibromyalgia, and headaches. 1, 2
• Key examination findings include jaw movement limitations, crepitus, and tenderness on palpation of masticatory muscles. 1

Neuropathic Pain Conditions

• Post-traumatic trigeminal pain/atypical odontalgia presents as continuous burning, tingling, or sharp pain localized to the tooth-bearing area, often following dental procedures (root canal therapy, extractions, implants) within 3-6 months of trauma. 1
• Patients frequently have a history of poor analgesia at the time of the dental procedure when symptoms started. 1
• Examination may reveal allodynia or other sensory changes, with qualitative sensory testing helpful for diagnosis. 1
• Management follows neuropathic pain protocols, though there is a high percentage of treatment failures. 1, 3

Acute Periodontal Lesions

Necrotizing Periodontal Disease

• Presents with three typical clinical features: papilla necrosis, gingival bleeding, and pain—representing the most severe conditions associated with dental biofilm with very rapid tissue destruction. 4
• Risk factors include HIV infection, malnutrition, stress, and tobacco smoking that alter host response. 4
• Treatment consists of superficial debridement, careful mechanical oral hygiene, chlorhexidine rinsing, and daily re-evaluation, with metronidazole as first-line systemic antimicrobial in severe cases. 4

Pericoronitis

• Inflammation of soft tissue overlying a partially erupted tooth, typically presenting with localized pain and swelling. 5
• Localized cases respond to irrigation, though secondary cellulitis can develop requiring more aggressive management. 5

Traumatic and Mechanical Causes

• Direct trauma to gingival tissues from aggressive brushing, dental appliances, or foreign body impaction can cause acute pain without infection. 4
• Erosive lesions may result from direct trauma or breaking of vesicles and bullae. 4

Critical Life-Threatening Causes to Exclude

Giant Cell Arteritis (Age >50 Years)

• Must be immediately recognized in patients over 50 years old presenting with jaw claudication (pain with chewing), temporal region pain, scalp tenderness, visual disturbances, fever, and malaise. 2, 6
• Physical examination reveals absent temporal artery pulse, temporal artery tenderness, and possible tongue cyanosis. 6
• Laboratory testing shows markedly elevated ESR and C-reactive protein. 6
• Immediate high-dose corticosteroid therapy (minimum 40 mg prednisone daily) is required to prevent permanent vision loss and should NOT be delayed while awaiting temporal artery biopsy. 6

Trigeminal Neuralgia

• Paroxysmal attacks of sharp, shooting, electric shock-like pain in the trigeminal distribution, triggered by light touch, washing, cold wind, eating, or brushing teeth. 1, 2, 6
• Refractory period exists between attacks. 1
• MRI is required to exclude tumors, multiple sclerosis, or neurovascular compression. 6

Other Important Differential Diagnoses

Salivary Gland Disorders

• Salivary stones cause intermittent pain characteristically occurring just before eating, with tenderness on palpation of the submandibular gland. 2, 6
• Bimanual examination reveals slow or absent salivary flow from the affected duct. 2
• Ultrasound imaging is the preferred diagnostic modality. 2

Mucocutaneous and Allergic Disorders

• Oral mucosal diseases (lichen planus, herpes zoster, herpes simplex, recurrent oral ulceration) present with pain associated with visible lesions. 2
• Allergic reactions to dental materials or medications can cause acute gingival inflammation and pain. 4

Burning Mouth Syndrome

• Rare chronic condition characterized by burning of the tongue and oral mucosa, seen predominantly in peri- and post-menopausal women. 1
• Oral mucosa appears normal on examination. 1
• Represents a disorder of peripheral nerve fibers with central brain changes. 1

Diagnostic Approach

Essential History Elements

• Timing and quality of pain (continuous vs. episodic, burning vs. sharp vs. aching). 1
• Aggravating factors (eating, jaw movement, light touch, temperature changes). 1, 2
• Recent dental procedures or trauma within 3-6 months. 1
• Age >50 with jaw claudication or systemic symptoms warrants immediate ESR and CRP testing. 6

Physical Examination Priorities

• Palpation of temporal arteries for tenderness, nodularity, or absent pulse in patients >50 years. 6
• Light touch testing in all three trigeminal divisions to identify trigger zones or sensory abnormalities. 6
• Bimanual palpation of salivary glands and floor of mouth. 2, 7
• Assessment of jaw movement, crepitus, and masticatory muscle tenderness. 1

Common Pitfalls to Avoid

• Delayed recognition of giant cell arteritis in patients over 50 years with jaw claudication can result in irreversible vision loss. 2, 6
• Overlooking psychological factors (depression, catastrophizing) in TMD increases risk of chronicity, as up to 30% of acute TMD cases become chronic. 2
• Performing irreversible dental procedures (extractions, root canals) in patients with neuropathic pain without proper diagnosis leads to continued pain and unnecessary procedures. 3
• Up to one-third of patients attending chronic facial pain clinics have undergone prior irreversible dental procedures without success. 3