The Effect on the Nasal Valve and Nasal Obstruction of Botulinum Toxin Injection Applied to the Nasoglabellar Region

Botulinum toxin A (BoT-A) injection has been used frequently and safely for many years for the elimination of facial wrinkles. Botulinum toxin, which is applied to various mimic muscles, is also applied to the nasal muscles. However, the effect of BoT-A applied to the nasal muscles on nasal obstruction, which is one of the most important nasal functions, is unknown. Although a few studies in literature have shown nasal obstruction and nasal valve collapse occurring with peripheral type facial paralysis, the pathophysiological mechanism through which this is formed has not been fully clarified. The aim of this study was to apply objective and subjective methods to investigate the effect on the nasal valve area and nasal obstruction of botulinum toxin injection applied to the nasoglabellar region. The study included 16 volunteers who underwent BoT-A injection to the nasoglabellar region. For all the study participants, the injections were administered as a total of 20 IU to 5 points in the glabellar region and 3 IU to each of the transverse nasal muscles. Before and at 1 month after the injections, each nasal passage of each subject (total 32 nasal passages) was evaluated separately with acoustic rhinometry. Nasal obstruction was evaluated before and at 1 month after the injection with the NOSE scale (Nasal Obstruction Symptom Evaluation). For standardisation and to eliminate the effects of the nasal cycle, the acoustic rhinometry was performed 10 mins after decongestion of both nasal passges with oxymetazoline. The NOSE scale was completed by each subject immediately before the administration of nasal decongestant. The NOSE scale points were determined as mean 6.3±5.5 before the injection and 3.8±5.9 at 1 month after the injection, but the decrease was not statistically significant (p=0.119). For the total 32 nasal passages, the Minimal Cross-sectional Area 2 (MCA2) values representing the cross-sectional area of the nasal valve were determined as mean 1.20±0.27 cm after nasal passage decongestion and 1.22±0.29 after the injection. The difference was not determined to be statistically significant (p=0.741). In conclusion, the results of this study demonstrated that BoT-A injection applied to the nasoglabellar region did not create a significant change in the MCA2 value showing the cross-sectional area of the nasal valve region, and subjectively there was no difference in the NOSE scale evaluating nasal obstruction.