Does the DN4 Questionnaire Help Identify Persistent Dentoalveolar Pain (PDAP)?

Objectives: The frequency of PDAP ranges between 1.0% to 5.3%. It is likely neuropathic in origin with 85%- 97% of PDAP patients displaying at least 1 side-to-side difference in qualitative sensory testing of pin-prick, cold or touch stimulation and often complaining of neurosensory disturbances such as burning and tingling. Many clinicians are unaware of these subtle signs and symptoms. The Douleur Neuropathique 4 (DN4) questionnaire is a validated tool that was developed to help diagnose patients with neuropathic pain. This study aims to investigate if the use of DN4 questionnaire helps clinicians in identifying PDAP in an endodontic referral clinic setting.

Methods: A retrospective analysis of patient records was conducted to determine the frequency of PDAP diagnosis over a six month period of patients referred to a specialist endodontic clinic at a UK dental hospital when the DN4 questionnaire was not in use. This was compared to a prospective 6 month study with clinicians using the DN4 questionnaire in the same clinic when no dental cause of pain could be identified. Diagnoses were confirmed by a specialist with an interest in facial pain. Descriptive statistics were used to compare frequencies of diagnoses between retrospective and prospective data.
Results: Retrospective study included 1181 patient records and no cases of PDAP were identified. Prospective study included 1124 patients in a six month period. 17 patients were diagnosed with non-inflammatory non-odontogenic pain when DN4 was used in these cases. 14 cases returned for specialist follow-up and all 14 were confirmed to have a diagnosis of PDAP (1.24%) by a second specialist. 3 patients failed to attend for follow-up.

Conclusions: Use of the DN4 improved the diagnosis of PDAP in specialist endodontic referral clinic. This questionnaire may be used as an aid to clinicians to help identify the subtle signs and symptoms of PDAP.