This prospective observational study will evaluate pain outcomes in patients with neuropathic dental pain (Atypical Odontalgia/Phantom Tooth Pain) who undergo directional deep brain stimulation (DBS). Participants will complete validated pain, disability, quality-of-life, and mood assessments before surgery and following DBS programming. Directional stimulation will be applied to different thalamic targets to determine whether specific stimulation settings are associated with greater pain relief. The study aims to characterize changes in pain and quality of life following DBS and to identify the stimulation target associated with the greatest reduction in neuropathic dental pain.

Neuropathic dental pain, also known as Atypical Odontalgia (AO) or Phantom Tooth Pain (PTP), is a chronic pain condition characterized by persistent tooth or facial pain in the absence of identifiable dental pathology. The condition is thought to result from injury to peripheral nerve structures that leads to alterations in central pain processing. Standard treatments, including antidepressants, neuroleptic medications, local anesthetic injections, corticosteroids, and nerve blocks, may provide relief for some patients; however, a subset of patients continue to experience debilitating pain despite these interventions.

Deep brain stimulation (DBS) is an established neurosurgical therapy for several neurological disorders and has been used off-label for the treatment of chronic neuropathic pain. Previous studies suggest that stimulation of thalamic structures involved in pain processing, including the ventral posteromedial nucleus (VPM), centromedian nucleus (CM), and anterior pulvinar (aPu), may provide pain relief for neuropathic facial pain. However, no established DBS target currently exists for neuropathic dental pain.

This prospective observational study will evaluate pain outcomes in patients with neuropathic dental pain who undergo directional DBS. Directional DBS leads will be implanted in a location that permits stimulation of the VPM, CM, and aPu regions of the thalamus. Following surgery, participants will undergo routine clinical programming during which stimulation settings will be systematically adjusted to direct stimulation toward each target region, as well as ring-mode stimulation and an off-stimulation condition. Participants will remain blinded to the stimulation settings.

Participants will complete validated measures of pain, pain-related disability, quality of life, and depressive symptoms before surgery and after completion of the programming period. Visual Analog Scale (VAS) pain ratings will also be collected following each stimulation condition to evaluate differences in pain relief between targets. The primary objective is to assess changes in pain levels associated with different stimulation settings and identify the stimulation target associated with the greatest reduction in neuropathic dental pain. Secondary objectives include evaluating changes in pain-related disability, quality of life, and mood following DBS treatment.

The findings from this study will provide preliminary evidence regarding optimal thalamic stimulation targets for neuropathic dental pain and may inform future research and treatment approaches for patients with this challenging and currently underserved condition.

Inclusion Criteria:

• Age 19 to 80 years.
• Diagnosis of Atypical Odontalgia (AO) (also known as neuropathic dental pain).
• Receiving deep brain stimulation (DBS) treatment for AO due to inadequate response to conventional therapies, including: Pharmacological therapies, and/or Local anesthetics, corticosteroid injections, or nerve blocks.
• Able and willing to provide informed consent.

Exclusion Criteria:

• Refusal or inability to provide informed consent.
• Known major depression.
• Acute psychosis.