Abstract
Objective: Burning mouth syndrome (BMS) is a chronic and often debilitating orofacial pain condition characterized by a burning sensation in the oral mucosa without clear abnormal lesions. While its etiology is considered multifactorial, the underlying pathophysiology remains unclear. This narrative review aims to synthesize existing functional magnetic resonance imaging (fMRI) studies to shed light on the central neural mechanisms contributing to BMS. Methods: A focused electronic search was conducted across the PubMed and J-STAGE databases for relevant articles published in English from January 2000 to May 2025. The review prioritized studies investigating brain structure and function using fMRI in individuals with BMS. Results: Our synthesis of the literature consistently demonstrated that the brains of individuals with BMS exhibit augmented connectivity within the medial pain system and a diminished gray matter volume in the medial prefrontal cortex (mPFC). These findings suggest a crucial role for altered brain circuitry, particularly a reduction in the output of the basal ganglia dopamine system, in the experience of BMS pain. Conclusions: The consistent fMRI findings strongly indicate that BMS involves significant functional and structural brain alterations. The observed changes in the mPFC and its connections to the basal ganglia dopamine system highlight this pathway as a potential target for both pharmacological and non-pharmacological neurological interventions for individuals with BMS.