title: Thermal welding vs. cold knife tonsillectomy: a comparison of voice and speech.
abstract: OBJECTIVE
  To compare acoustic, aerodynamic and perceptual voice and speech parameters in thermal welding system tonsillectomy and cold knife tonsillectomy patients in order to determine the impact of operation technique on voice and speech.
  
  
  METHODS
  Thirty tonsillectomy patients (22 children, 8 adults) participated in this study. The preferred technique was cold knife tonsillectomy in 15 patients and thermal welding system tonsillectomy in the remaining 15 patients. One week before and 1 month after surgery the following parameters were estimated: average of fundamental frequency, Jitter, Shimmer, harmonic to noise ratio, formant frequency analyses of sustained vowels. Perceptual speech analysis and aerodynamic measurements (maximum phonation time and s/z ratio) were also conducted.
  
  
  RESULTS
  There was no significant difference in any of the parameters between cold knife tonsillectomy and thermal welding system tonsillectomy groups (p>0.05). When the groups were contrasted among themselves with regards to preoperative and postoperative rates, fundamental frequency was found to be significantly decreased after tonsillectomy in both of the groups (p<0.001). First formant for the vowel /a/ in the cold knife tonsillectomy group and for the vowel /i/ in the thermal welding system tonsillectomy group, second formant for the vowel /u/ in the thermal welding system tonsillectomy group and third formant for the vowel /u/ in the cold knife tonsillectomy group were found to be significantly decreased (p<0.05).
  
  
  CONCLUSIONS
  The surgical technique, whether it is cold knife or thermal welding system, does not appear to affect voice and speech in tonsillectomy patients.
authors.affiliation: Lutfiye Nuri Burat State Hospital, Department of Otolaryngology, Istanbul, Turkey.
authors.forename: Saban
authors.initials: S
authors.lastname: Celebi
authors.forename: Kursat
authors.initials: K
authors.lastname: Yelken
authors.forename: Oner
authors.initials: O
authors.lastname: Celik
authors.forename: Umit
authors.initials: U
authors.lastname: Taskin
authors.forename: Murat
authors.initials: M
authors.lastname: Topak
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D015331:Cohort Studies; D003452:Cryosurgery / Q000009:adverse effects / Q000379:methods*; D004564:Electrocoagulation / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology; D018570:Risk Assessment; D013068:Speech Production Measurement; D018709:Statistics, Nonparametric; D014068:Tonsillectomy / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome; D014833:Voice Quality / Q000502:physiology*; D055815:Young Adult