What causes toothaches that only occur at night?

Nighttime Toothache: Causes and Management

Toothaches that occur exclusively or worsen at night are most commonly caused by increased awareness of pain when lying down and distracted stimuli are removed, combined with physiological changes including increased blood flow to the head when supine, nocturnal bruxism (teeth grinding), and sinus pressure changes. 1, 2

Primary Mechanisms of Nocturnal Tooth Pain

Positional and Hemodynamic Factors

• When lying flat, increased blood flow to the head elevates intrapulpal pressure in inflamed or infected teeth, intensifying pain perception. 2, 3
• This mechanism explains why dental pain from pulpitis or periapical abscess characteristically worsens at night when horizontal. 1

Nocturnal Bruxism (Teeth Grinding/Clenching)

• Unconscious grinding or clenching during sleep creates mechanical stress on teeth, periodontal structures, and the temporomandibular joint, producing pain that manifests during or immediately after sleep. 4, 5
• Bruxism-related pain typically presents as dull, aching discomfort affecting multiple teeth rather than sharp, localized pain. 4

Reduced Distraction and Pain Threshold

• During daytime activities, cognitive distraction suppresses pain awareness; at night, the absence of competing stimuli amplifies pain perception. 1, 6
• This psychological component does not diminish the reality of the pain but explains timing patterns. 3

Sinus-Related Mechanisms

• Maxillary sinusitis causes referred pain to upper posterior teeth that worsens when lying down due to increased sinus pressure and impaired drainage in the supine position. 4
• Pain from sinusitis typically affects multiple upper teeth simultaneously and may be accompanied by nasal congestion or facial pressure. 4

Critical Differential Diagnoses to Consider

Odontogenic Causes (Tooth-Related)

• Reversible or irreversible pulpitis from deep caries, cracked teeth, or failing restorations. 1, 2
• Periapical abscess or acute apical periodontitis. 1
• Periodontal abscess or advanced periodontal disease. 2
• These conditions require dental examination with percussion testing, thermal testing, and periapical radiographs. 4

Nonodontogenic Causes (Not Tooth-Related)

Temporomandibular disorders (TMD) are the most common nonodontogenic cause of facial pain mimicking toothache, affecting 5-12% of the population with peak incidence at ages 20-40. 4

• TMD pain is typically dull, continuous, and worsens with jaw function; it may be accompanied by jaw clicking, limited opening, or muscle tenderness. 4

Trigeminal neuralgia and painful post-traumatic trigeminal neuropathy can present as sharp, electric-shock-like tooth pain. 2, 3

• These neuropathic conditions are often misdiagnosed, leading to unnecessary dental procedures. 3

Cardiac ischemia can rarely present as mandibular tooth pain, particularly in the left lower jaw. 2, 3

• This must be considered in patients with cardiac risk factors, especially if pain occurs with exertion. 2

Migraine and other primary headaches can manifest as throbbing tooth pain. 3

• Associated symptoms include photophobia, phonophobia, nausea, or unilateral distribution. 3

Diagnostic Red Flags Suggesting Nonodontogenic Pain

The following features strongly suggest pain is NOT from the tooth itself and warrant investigation for alternative causes: 1, 2

• No identifiable dental pathology on examination or radiographs despite severe pain. 1
• Pain persists after appropriate dental treatment (endodontic therapy or extraction). 1, 7
• Local anesthetic block of the suspected tooth fails to eliminate the pain. 1
• Constant, burning, or electric-shock quality rather than throbbing or pressure-like. 1, 2
• Multiple teeth affected simultaneously without clear dental cause. 1
• Pain present for months or years with recurrent episodes despite multiple interventions. 1, 7

Medication-Related Considerations

Xerostomia (dry mouth) from medications can worsen nighttime dental pain by reducing protective saliva flow during sleep. 4

• Culprit medications include antidepressants (especially tricyclics), antihistamines, anxiolytics, antimuscarinics, decongestants, and antipsychotics. 4
• Consider medication adjustment or saliva substitutes if xerostomia is contributing. 4

Recommended Diagnostic Approach

Initial Evaluation

Perform thorough dental examination including: 4

• Visual inspection for caries, cracks, or gingival inflammation
• Percussion testing of suspected teeth
• Thermal sensitivity testing (cold and heat)
• Palpation of surrounding soft tissues and lymph nodes

Obtain periapical radiographs of the affected area to identify: 4

• Periapical radiolucencies suggesting abscess or granuloma
• Deep caries approaching the pulp
• Bone loss from periodontal disease
• Impacted teeth or retained roots

When Dental Pathology Is Unclear

If examination and radiographs do not reveal adequate dental cause for the severity of pain, consider: 1, 2, 3

• Diagnostic local anesthetic block: Complete pain relief confirms odontogenic source; persistent pain suggests nonodontogenic etiology. 1
• TMD screening: Assess for jaw clicking, limited opening (<40mm), muscle tenderness on palpation, and pain with jaw movement. 4
• Sinus evaluation: Check for facial tenderness over maxillary sinuses, nasal congestion, and whether pain affects multiple upper posterior teeth. 4
• Neuropathic pain features: Ask about electric-shock quality, trigger points, or previous facial trauma/surgery. 2, 3

Management Strategy

For Confirmed Odontogenic Pain

Definitive dental treatment is required: 1, 2

• Endodontic therapy for irreversible pulpitis or necrotic pulp
• Extraction if tooth is non-restorable
• Periodontal treatment for abscess or advanced disease
• Restoration of carious lesions

Interim symptomatic relief while awaiting definitive treatment: 6

• NSAIDs (ibuprofen 400-600mg every 6-8 hours) for anti-inflammatory effect
• Elevate head with extra pillows to reduce intrapulpal pressure
• Avoid hot foods/beverages that may exacerbate pulpal inflammation

For Nocturnal Bruxism

Fabricate a hard stabilization splint (occlusal guard) for nighttime wear. 4

• This is the only appliance type with evidence for efficacy in TMD-related pain. 4
• Soft splints or appliances that do not account for occlusion may worsen symptoms. 4

For Nonodontogenic Pain

Avoid irreversible dental procedures (endodontics, extractions) when nonodontogenic etiology is suspected. 1, 3, 7

• Inappropriate dental treatment will not relieve pain and may complicate the clinical picture. 3, 7
• Refer to appropriate specialist: orofacial pain specialist, neurologist, or ENT depending on suspected etiology. 2, 3

Common Pitfalls to Avoid

Do not proceed with endodontic treatment or extraction based solely on patient-reported nighttime pain without objective findings. 1, 7

• Many patients undergo multiple unnecessary procedures due to failure to recognize nonodontogenic pain. 3, 7

Do not assume all tooth pain requires antibiotics. 3

• Antibiotics are indicated only for spreading infection with systemic signs (fever, swelling, lymphadenopathy), not for localized pulpitis or chronic pain. 3

Do not dismiss patient concerns if initial dental examination is negative. 2, 7

• Persistent pain warrants systematic evaluation for nonodontogenic causes rather than repeated dental interventions. 7

Recognize that multiple conditions may coexist (multifactorial pain). 4

• A patient may have both dental pathology AND TMD or sleep disorders contributing to nighttime symptoms. 4