Investigation of Olfactory Function Following Septorhinoplasty in Iranian Population by Rapid Smell Test (RST)

Introduction: All surgical procedures on nose affect the olfactory function to some extent. There are different viewpoints about olfactory function after septorhinoplasty. We aim to investigate smell perception changes in patients following septorhinoplasty. In this study the use of Rapid Smell Test (RST) as a fast and reliable clinical tool was investigated. Methods: A prospective cohort study was done in Rasool Akram teaching hospital in 2018 and 2019. Group of 74 septorhinoplasty candidates aged over 18 was selected by convenience. Persian Smell Identification Test (PSIT) and rapid smell test (RST) was obtained from patients before surgery and one month after, if needed three months after and six months after. In addition for patients with dysfunction in any of follow up periods (one month, 3 months and 6 months after surgery) smell magnitude test (SMT) was used. All data were analyzed using Statistical Package for Social Sciences, version 24.0 (IBM SPSS Statistics Inc., Chicago, IL, USA). Results: Out of 74 patients participating in this study 67 were female. Mean age of 25.68±5.18 years was recorded for participants. All patients before surgery had PSIT score more than 19 and the mean PSIT score before operation was 22.63±1.39. Also all patients scored 5 out of 5 in RST before surgery. Mean PSIT score one month after surgery decreased to 22.21±2.20 but still 93 percent (69 patients) of participants were in range for normal olfactory function. We recorded this to be significant (p value = 0.044). RST after one month showed the same results. The difference between RST before and after surgery was also significant (p value = 0.024). For those 5 patients with abnormal olfactory function PSIT and RST were done 3 months after operation which determines normal olfactory function for all of them. As well as PSIT, RST also shows the same results and five participants recorded 5 out of 5 three months after surgery. Conclusion: This study showed changes in olfactory function after septorhinoplasty will resolve at most 3 months after surgery and it is safe to say there is no effect on olfactory function three months after operation. Also we demonstrated that RST can be a fast and reliable tool for assessing patients’ olfactory function in clinical setting.