Chemosensory Functions After Glossectomy—A Cross‐Sectional Pilot Study

Abstract

Objective To evaluate potential interactions and compensatory mechanisms of subjectively impaired taste function with ortho‐ and retronasal olfaction after glossectomy. Study Design In this cross‐sectional pilot study, chemosensory functions were assessed in 25 patients with tongue carcinomas after glossectomy. The orthonasal‐, retronasal‐, and gustatory functions were tested with a mean time of 25 months after surgery with the Sniffin’ Sticks odor identification test kit (ISST), the Candy Smell‐27 test (CST‐27) and the Taste strip test (TST). Visual analog scales (VAS) were additionally used for self‐assessment of taste, flavor perception, and odor ranging from 0 (no perception) to 10 (excellent perception) and further correlated with our psychophysical evaluated outcome measures. Results The TST, ISST, and CST‐27 tests revealed that only eight (32%) and 13 (52%) glossectomy patients had normal taste and orthonasal function, e 21 (84%) patients showed normal retronasal function. Importantly, neither extent of resection and reconstruction nor prior radiotherapy affected chemosensory functions. Contrary, 20 (80%) patients rated their taste and flavor perception as acceptable (VAS >5). Results of the TST, ISST, and CST‐27 tests did not correlate with the equivalent self‐assessments of taste (p = 0.260, r = 0.234), odor (p = 0.588, r = −0.114), and flavor (p = 0.728, r = 0.073) perception. Conclusion There was a significant discrepancy between self‐perception of taste and flavor and assessed gustatory function after glossectomy. A contribution of the intact retronasal olfactory system could be a possible explanation of our results. Level of Evidence 4 Laryngoscope, 133:375–382, 2023

A Simple Taste Test for Clinical Assessment of Taste and Oral Somatosensory Function—The “Seven-iTT”

“…These self-reported ratings distinguished well between the two groups. These data are in accordance with previous studies that showed a positive relationship between subjects’ self-assessment and taste identification performance [ 41 , 42 ], whereas some other studies have not found this correlation on patients [ 43 , 44 , 45 , 46 ] or healthy subjects [ 47 ]. This divergence may be due to a common mistake in discrimination between decreased taste and retronasal olfaction [ 1 ], thus some patients who complain taste loss might not respond accurately to this type of questionnaire.…”

Association of gustatory dysfunction and Alzheimer's disease: a systematic review and meta-analysis

“…The gustatory pathway has been shown to be modulated by sensory input from cranial nerves I and V, and olfaction is an important part of taste (33) . It also has been reported that the retronasal olfactory system is involved in the discrepancy between self-perception of taste and assessed gustatory function testing (36) . In addition, it has been suggested that patients may have mistaken an actual olfactory deficit for a subjective loss of taste since olfaction and gustation are interrelated and both are vital for the perception of flavor (35) .…”