Is Burning Mouth Syndrome a Neuropathic Pain Disorder? A Systematic Review.

Aims: To conduct a systematic review compiling an update on the pathophysiology of burning mouth syndrome (BMS) by reviewing the theories and studies published in the last 5 years that consider BMS a neuropathic disease.

Methods: A literature review was carried out in April 2020 on the PubMed database by using the following MeSH terms: "(burning mouth OR burning mouth syndrome OR burning mouth pain OR sore mouth OR burning tongue OR oral neuropathic pain OR glossodynia OR stomatopyrosis) AND (etiopathogenesis OR etiopathological factors OR etiology)."

Results: The research carried out according to the methodology found 19 case-control studies (1 of which was in vivo) and 1 RCT. Of the 19 included studies, 8 showed an evidence score of 2-; 8 showed 2+; another 2 showed 2++; and 1 showed 1+. Quality studies on this topic are insufficient and heterogenous.

Conclusion: In the pathogenesis of BMS, both peripheral and central neuropathies appear to play a pivotal role. Nevertheless, the balance between them varies from case to case and tends to overlap. BMS does not seem to be a result of direct damage to the somatosensory nervous system, but a dysfunction in it and in the brain network.