A 72-year-old woman arrives with a tongue that ‘burns as if scalded'. Symptoms begin after dental treatments. After careful exclusion of local causes, dysaesthesia persists. She improves on a modest, individualised combination – titrated to address sleep, mood, and comorbidities – plus brief psychosocial support. In practice this is ordinary; in the literature it is almost invisible.

Burning mouth syndrome (BMS) exposes a wider problem in oral medicine: we have treated randomised controlled trials (RCTs) as the sole passport to guidance, yet many chronic oral/facial pain conditions in older, multimorbid patients do not fit pill-versus-placebo boxes. When our rules see only what RCTs can capture, effective chairside care disappears.

Keep RCTs as the spine of inference, but add the muscles of real-world evidence (RWE). BMS is heterogeneous and fluctuating. Dental treatments may trigger symptoms, but pathophysiology is multifactorial. Trials prefer narrow entry criteria, single agents, and short follow-up. Clinicians individualise low-dose combinations, integrate behavioural strategies with oral management, and allow time for neurosensory adaptation. A ‘no effect' result can reflect a mismatch between tidy methods and complex illness.

The blind spot extends beyond BMS: older adults remain underrepresented, distorting external validity.1,2 Responsible use of RWE is already described by NICE.3,4 What should we do now?

  • Build simple clinic registries with a minimum dataset (comorbidities, severity, sleep, mood, oral status, dose) captured during routine care; prioritise outcomes patients value – tolerating dentures, eating, socialising

  • Reward pragmatic designs: registry-based trials and N-of-1 series that permit titration and combination therapy

  • Stop excluding the people we treat: require justification for excluding older, multimorbid patients.

When guidance recognises only the classic trials, patients cycle through ‘evidence-based' yet ineffective single agents while multimodal regimens that help remain off-guideline. BMS is a case study; if journals systematically incorporate RWE alongside RCTs, we can close an evidence blind spot that harms older people.

During the preparation of this study, the authors employed the ChatGPT 5 Thinking (OpenAI) system to translate the manuscript from Japanese into English, improve readability, rephrase text where appropriate, and ensure proper grammar. Subsequently, the authors conducted a thorough review and made any necessary editorial revisions. The authors assume full responsibility for the final content presented in this publication.