Positive Long-Term Effects of Third Molar Extraction on Taste Function.

Taste and other neurosensory defects have been reported postoperatively in a number of patients who have undergone mandibular third molar extraction (TME). Although the taste deficits are generally believed to resolve within a year, the long-term effects of TME remain unknown. We retrospectively examined the whole-mouth taste function of 891 individuals who had received TMEs, on average, more than 2 decades earlier, and 364 individuals who had not undergone TME. All had been extensively tested for chemosensory function at the University of Pennsylvania Smell and Taste Center over the course of the last 20 years. The whole-mouth identification test incorporated 2 presentations each of 5 different concentrations of sucrose, sodium chloride, citric acid, and caffeine. Analyses of covariance (age = covariate) found those with histories of TME to exhibit better overall test scores for all 4 taste qualities than nonoperated controls. Such scores were not associated with the time since the TME. In both groups, women outperformed men and function declined with age. The basis of this phenomenon, which requires confirmation from prospective studies, is unknown, but could reflect sensitization of CN VII nerve afferents or the partial release of the tonic inhibition that CN VII exerts on CN IX via central nervous system processes.

Predominant Qualities Evoked by Quinine, Sucrose, and Capsaicin Associate With PROP Bitterness, but not TAS2R38 Genotype.

Genetic variability in the ability to taste thiourea compounds has been studied for 80+ years. Over the last 3 decades, many studies have reported perceived intensity of concentrated propylthiouracil (PROP) associates with greater intensity from a broad range of stimuli, including nonbitter tastants, irritants, and retronasally delivered odorants. Thus, PROP phenotype has become a common measure of individual differences in orosensation. Much, but not all, of the phenotypic variation in PROP bitterness is explained by TAS2R38 polymorphisms. While differences in PROP bitterness are clearly due to genetic variation, mechanistically it is challenging to envision how this receptor (narrowly tuned to the N-C=S moiety) relates to overall orosensory response. Here, we report data for 200+ individuals who had been genotyped for TAS2R38 and phenotyped for PROP in a laboratory setting. Participants also reported the intensity of quinine, capsaicin, and sucrose on a general Labeled Magnitude Scale. Our data recapitulate earlier reports associating PROP bitterness with the intensity of the predominant qualities of sucrose, quinine, and capsaicin; however, we also find correlations between the intensities of sucrose, quinine, and capsaicin were much stronger with each other than with PROP. As expected, TAS2R38 diplotype did not associate with the intensity of sucrose, quinine, or capsaicin. The strength of PROP-capsaicin and PROP-sucrose relationships increased after grouping participants by TAS2R38 diplotype, with the greatest increases in association observed within homozygotes. Collectively, this suggests the suprathreshold intensity of PROP is a confounded phenotype that captures both genetic variation specific to N-C=S compounds and overall orosensation.

Hyperosmia and Hypergeusia As Potential Clues in Diagnosing Adrenal Insufficiency: A Case Report.

Adrenal insufficiency often presents with nonspecific symptoms, physical findings, and laboratory results, leading to diagnostic challenges. However, reports have indicated that specific symptoms such as hypergeusia (hypersensitivity to taste) and hyperosmia (hypersensitivity to smell) can also occur. We report the case of a 60-year-old male with loss of appetite, fatigue, and polyarthralgia, where a detailed medical history revealed the cause of anorexia to be hypergeusia and hyperosmia. These specific symptoms led to the diagnosis of adrenal insufficiency. Treatment with oral steroids for secondary adrenal insufficiency resulted in the improvement of his diverse symptoms. This case illustrates that in patients presenting with chronic nonspecific symptoms, inquiring about heightened taste and smell sensitivity can prompt suspicion of adrenal insufficiency. Moreover, this case serves as a reminder that careful medical history taking in patients with nonspecific symptoms can uncover specific findings that may be diagnostic clues.

Examination of the taste disorder associated with gynecological cancer chemotherapy.

OBJECTIVE: Taste disturbance is known to occur as one of the adverse events associated with chemotherapy for gynecological cancer, but few studies have attempted to assess it in practical terms. Therefore, a range of taste tests was performed in gynecological cancer patients. METHODS: The patients were 23 women with gynecological cancer being treated with anticancer agents. Subjective symptoms of altered taste were classified, and objective findings were obtained with the following four gustatory tests: serum trace element (zinc, copper, iron) levels, tongue cultures, electrogustometry, and the filter paper disc tests. RESULTS: Of the 23 subjects, 11 perceived taste disturbances. The serum zinc level was consistently below the lower limit of normal. On tongue cultures, indigenous bacteria were seen in all patients during the entire treatment period. Electrogustometry revealed a tendency for the development of hypogeusia in the chorda tympani nerve field. Conversely, hypergeusia tended to develop gradually in the greater petrosal nerve field. The filter paper disc test revealed a tendency for the development of hypergeusia for sweetness, saltiness, and sourness in the chorda tympani nerve field. Hypogeusia for bitterness tended to develop with increasing number of chemotherapy cycles. The glossopharyngeal nerve field exhibited the same tendencies as observed in the chorda tympani nerve field. In the greater petrosal nerve field, there was a tendency for the development of hypergeusia for sweetness, sourness, and bitterness. CONCLUSIONS: Abnormal test results were seen in half of patients after cancer chemotherapy.

Sweet Taste Dysgeusia in a Patient with Indapamide-Related Hyponatremia: Case Report and Review of the Literature.

Sweet taste dysgeusia is a rare symptom where patients experience all food as having a sweet taste. While its cause is still unknown, it has been increasingly reported in the setting of lung cancer and syndrome of inappropriate secretion of antidiuretic hormone-related hyponatremia. In this case report, we present what we believe to be the first case of sweet taste dysgeusia in a non-cancer context. We will briefly review and summarize all published cases describing this symptom and also reflect upon the nature of this condition focusing on the role of serum sodium levels in sweet taste receptor modulation.

Gustatory dysfunction.

Tastes in humans provide a vital tool for screening soluble chemicals for food evaluation, selection, and avoidance of potentially toxic substances. Taste or gustatory dysfunctions are implicated in loss of appetite, unintended weight loss, malnutrition, and reduced quality of life. Dental practitioners are often the first clinicians to be presented with complaints about taste dysfunction. This brief review provides a summary of the common causes of taste disorders, problems associated with assessing taste function in a clinical setting and management options available to the dental practitioner.