Abstract
Purpose :
Thyroplasty type I and arytenoid adduction surgery are effective surgical treatments for dysphonic patients with unilateral vocal fold paralysis. Adduction of the vocal fold decreases the glottal gap during phonation and improves breathy voice. The decrease of glottal area during inspiration, however, may cause an increase in upper airway resistance. The purpose of this study is to quantify the glottal area during inspiration and to examine the relationship between glottal area and upper airway resistance in phonosurgical treatment.
Materials and Methods :
Eleven patients with unilateral vocal fold paralysis underwent multi-slice helical computerized tomography (MSHCT) before and after phonosurgical treatment. Seven of them underwent pulmonary function tests and FEV1.0/PEF ratio was calculated to evaluate upper airway obstruction. Six of them underwent body plethysmography to evaluate airway resistance. Image analysis software was developed to measure the glottal area during inspiration.
Results :
Glottal area during inspiration was significantly decreased after phonosurgical treatment. The mean glottal area decreased in size to 77.0% of that before phonosurgery. The FEV1.0/PEF ratio was not significantly increased after phonosurgery. The mean airway resistance was 114.4% of that before phonosurgery. A correlation between glottal area and airway resistance was not found.
Conclusion :
It is possible to measure glottal area by MSHCT, and upper airway resistance does not significantly increase after phonosurgical treatment.
