Dane Kim
| Dane Kim |
Dane Kim, Richard L. Doty
Richard L. Doty
Smell and Taste Center, Otorhinolaryngology: Head and Neck Surgery, Perelman School of Medicine
Introduction
Third molar extraction (TME) can produce post-operative taste deficits in some individuals. This reflects iatrogenic insults to the chorda tympani nerve where it accompanies the lingual nerve near the third molar capsule. Although return to normal usually occurs within a few months, the long-term effects of TME on taste function are unknown and were evaluated in this study.
Methods
891 TME participants whose surgery occurred decades earlier and 364 control subjects who had not undergone TME were evaluated for taste function in a university-based specialized smell and taste center that provides primary and tertiary care for persons referred by various specialties for assessment and treatment of smell and taste disorders. Whole-mouth taste identification test scores based on two presentations each of five different concentrations of sucrose (0.08,0.16,0.32,0.64,1.28 molar [M]), sodium chloride (0.032,0.064, 0.128,0.256,0.512 M), citric acid (0.0026,0.0051,0.0102,0.0205,0.0410 M), and caffeine (0.0026,0.0051,0.0102,0.0205,0.0410 M). Differences assessed using both parametric and non-parametric analyses that controlled for age and sex effects.
Results
The average test scores for all four taste qualities were higher (better) for the TME group than for the controls by 5.69% (odds ratio:2.03 (95% CI:1.56, 2.64) and unrelated to time since TME. This phenomenon was present for each taste quality assessed individually. In both study groups, women outperformed men and the test scores declined with age.
Conclusion
We demonstrate, for the first time, that TME can result in moderate long-term improvement of taste function. This contrasts to well-established short-term taste decrements observed in a small number of cases. Such enhancement could reflect iatrogenic sensitization of CN VII nerve afferents as well as the partial release of the central tonic inhibition that CN VII exerts on CN IX, the nerve that innervates the most taste buds. Prospective studies are needed to confirm this novel and important finding.