ABSTRACT
BACKGROUND AND OBJECTIVES: Many people have been concerned about the voice change after uvulopalatopharyngoplasty (UPPP). A number of studies reported acoustic changes after UPPP. However, there have not been any reports regarding the association of anatomic changes and acoustic results after UPPP. The purpose of this study is to analyze changes of the voice and changes in the vocal tract after UPPP and to evaluate whether the anatomical changes of vocal tract have an effect on the voice change or not. SUBJECTS AND METHOD: By using computerized speech laboratory (CSL), we analyzed fourteen UPPP cases on the formant frequencies of six vowels (/a/, /i/, /u/, /o/, /e/) and three nasal consonants (/eom/, /eoung/, /kin/). By using MR image, we analyzed the changes of vocal tract four weeks after UPPP with preoperative findings in one case. RESULTS: In acoustic analysis, the second formant frequencies of /i/ and /u/ phonation were significantly reduced postoperatively compared to those of preoperative status. In imaging study of /i/ and /u/, the soft palate were contracted along with the widening of the oropharynx and the tongue was shifted toward posterior pharyngeal wall to compensate. CONCLUSION: UPPP reduced the second formant of /i/ and /u/, which did not result in serious voice change.