ICD-10 CODE K08.9l
The Clinical Syndrome
Atypical odontalgia (also known as persistent orodental pain syndrome) describes a heterogeneous group of pain syndromes that share in common the fact that the odontalgia cannot be classified as classic trigeminal neuralgia. The pain is continuous but may vary in intensity. It is almost always unilateral and may be characterized as aching or cramping rather than the shock-like neuritic pain typical of trigeminal neuralgia. The vast majority of patients suffering from atypical odontalgia are female. Atypical odontalgia can occur at any age, but has a peak incidence in the fifth decade of life. The pain is felt in a single tooth or its surrounding area and occurs most commonly in the maxillary region ( Fig. 16.1 ).
Headache may occur with atypical odontalgia and is clinically indistinguishable from the tension type of headache. Stress is often the precipitating, or an exacerbating, factor in the development of atypical odontalgia. Depression and sleep disturbance are also present in a significant number of patients. A history of dental or facial trauma, including dental extractions, root canal treatment, infection, or tumor of the head and neck may be elicited in some patients with atypical odontalgia, but in many cases no precipitating event can be identified.
Signs and Symptoms
Table 16.1 compares atypical odontalgia with trigeminal neuralgia. Unlike trigeminal neuralgia, which is characterized by sudden paroxysms of neuritic shock-like pain, atypical odontalgia is constant and has a dull, aching quality but may vary in intensity. The pain of trigeminal neuralgia is almost always within the distribution of one division of the trigeminal nerve, whereas atypical odontalgia invariably involves just a single tooth, its surrounding gingival tissue, or underlying bone. The trigger areas characteristic of trigeminal neuralgia are absent in patients with atypical odontalgia. Most important, no findings of pathological condition of the painful tooth or adjacent gingival tissues are seen on physical examination.
| Pain Factor | Trigeminal Neuralgia | Atypical Odontalgia |
|---|---|---|
| Temporal pattern of pain | Sudden and intermittent | Constant |
| Character of pain | Shock-like and neuritic | Dull, aching, cramping |
| Pain-free interval | Usual | Rare |
| Distribution of pain | One division of the trigeminal nerve | One tooth and surrounding area |
| Trigger areas | Present | Uncommon |
| Underlying psychopathology | Rare | Common |
Testing
Radiographs of the head are usually within normal limits in patients suffering from atypical odontalgia, but they may be useful to identify a tumor or bony abnormality. Magnetic resonance imaging (MRI) of the brain and sinuses can help the clinician identify intracranial pathology such as tumor, sinus disease, and infection ( Fig. 16.2 ). A complete blood count, erythrocyte sedimentation rate, and antinuclear antibody testing are indicated if inflammatory arthritis or temporal arteritis is suspected. Injection of the painful tooth with small amounts of local anesthetic can serve as a diagnostic maneuver to determine whether the tooth or adjacent structures are the source of the patient’s pain. Differential neural blockade can help distinguish primary tooth pathology from atypical odontalgia and reflex sympathetic dystrophy of the face ( Table 16.2 ). Complete relief of pain after injection of the painful tooth with local anesthetic suggests a local pathological process, whereas incomplete pain relief suggests the pathological process is more central. Thus, the diagnosis of atypical odontalgia is a strong possibility of underlying pathological condition of the trigeminal nerve, adjacent bone, brain, or brainstem. Complete relief of pain after ipsilateral stellate ganglion block is highly suggestive of reflex sympathetic dystrophy of the face. Psychological evaluation should be considered if significant coexistent depression or sleep disturbance is present.
