Evaluation of olfactory threshold changes in patients treated with rapid maxillary expansion

Aim: Rapid maxillary expansion (RME) provides an orthopedic effect that solves the problem of transverse deficiency of the maxilla. Moreover, it contributes positively to the functioning of the entire nasopharynx by increasing the cross-sectional area and volume of the nasal tract, thus reducing airway resistance. The aim of this study was to evaluate the changes in olfactory threshold after RME treatment of patients with maxillary transverse deficiency. Methodology: Olfactory threshold and identification tests as well as acoustic rhinometry parameter (Volume1, MCA1, Volume2, MCA2) measurements were conducted for 40 patients (11–16 years) before treatment (T0) and 6 months after (T1) rapid maxillary expansion application. Results: A significant improvement was observed when the olfactory threshold values at T0 (0.96 ± 0.07) and T1 (0.79 ± 0.13) (p < 0.001) were compared. A significant improvement was also observed upon comparing the identification test results at T0 (0.63 ± 0.13) and T1 (0.79 ± 0.11) (p < 0.001). The acoustic rhinometry results showed a significant increase in Volume 1, MCA1, Volume 2 and MCA2 in the right and left nasal cavities after treatment (p < 0.001). Conclusion: In this study, acoustic rhinometry showed that nasal cavity area and volume increased in patients who underwent rapid maxillary expansion therapy. Further, the olfactory functions measured by the olfactory threshold test and identification test improved significantly.    How to cite this article: Yıldırım M, Erdur EA, Erdur Ö, Metli ŞN. Evaluation of olfactory threshold changes in patients treated with rapid maxillary expansion. Int Dent Res 2022;12(Suppl.1):90-6. https://doi.org/10.5577/intdentres.435   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.