Physiology of Taste Disorders

Taste is integrated with retronasal olfaction in the brain to form flavor. Taste nerves are vulnerable to peripheral damage (e.g., otitis media, tonsillectomy, head injury, chemotherapy, radiotherapy), which can affect other oral sensations because of central interactions. Inhibition exerted by taste input governs this process, but individual differences make whole-mouth outcomes of regional nerve damage extremely variable: some individuals are unaffected, others experience severe loss, and some encounter intensified sensations that may elevate sweet-fat palatability and body mass. Patients may also report phantom taste (e.g., dysgeusia), touch, or pain sensations (e.g., burning mouth syndrome). To diagnose and treat these conditions effectively, emerging clinical tests measure regional versus whole-mouth sensation, phantoms, and oral anatomy. Scaling methods allowing valid group comparisons figure prominently in these efforts. Overall, advances in measuring oral sensory variation show strong potential for understanding clinical dysfunction.