Thermal sensory and pain thresholds in the tongue and chin change with age, but are not altered in burning mouth syndrome

Background: Burning mouth syndrome (BMS) is a chronic orofacial pain syndrome that occurs in middle-aged and postmenopausal women and poses a therapeutic challenge to dermatologists and dentists. It has been suggested previously that BMS is a small-fiber neuropathy. Aims: This study was designed to examine thermal sensory and pain thresholds in the oral mucosa and chin, both innervated by the trigeminal nerve, in patients with BMS, as well as in healthy controls. In addition, the study proposed to examine whether there are any differences in oral thermal and pain sensations between the advanced age group, where BMS is prevalent and a younger group. Results: Thermal and pain thresholds of BMS patients did not differ significantly from those of healthy subjects. An increased threshold to thermal warmth and a decreased threshold for cold sensation for the tongue and chin were noted in the group over 50 years in comparison with younger subjects, indicating a decreased sensitivity to thermal stimuli. The group over 50 years of age displayed an increased sensitivity to cold pain and a decreased sensitivity to hot pain in the tongue (compared with the chin). Conclusion: BMS patients do not demonstrate alterations in thermal and pain detection, thus failing to support a true small nerve neuropathy in this condition.