An investigation of retronasal testing of olfactory function in a Turkish population

The aim of this study was: (1) to perform a preliminary study for the validation of ''retronasal olfactory testing'' in the Turkish population to find the best way to evaluate smell and taste disorders in Turkey; (2) to determine if cultural differences make application of the test more difficult; and (3) to determine the flavors that participants had not yet tasted by using the survey method.

The study included 330 volunteers. Orthonasal olfactory function was assessed psycho-physically using the "Sniffin' Sticks" olfactory test. Retronasal olfaction was assessed using a collection of 20 available food powders applied to the oral cavity. Also, all participants filled in a questionnaire of 50 items about the flavors they had not tasted before.

The mean age of the participants was 26 ± 7.3 years. Participants were divided into 3 groups according to the "Sniffin' Sticks" test results: anosmia, hyposmia, and normosmia groups. Differences in retronasal olfaction scores were significant among the 3 groups.

The retronasal olfactory test appeared to perform well, but modifications of odorized powders or granules and distracters used in the retronasal olfactory test, taking into account Turkish cultural differences, is likely to improve its performance.