title: [Study on voice quality after different layers injured in vocal fold with CO2 laser microsurgery].
abstract: OBJECTIVE
  To investigate the nature of pathological voice after injured in different layers of vocal fold with CO2 laser microsurgery.
  
  
  METHODS
  50 cases of precancerous lesion (keratosis and leukoplakia) were treated with laser mucosa ablation. Glottal carcinoma (Tis-T2) were treated with laser microsurgery in mucosal stripping(30 cases) or with laser cordectomy(60 cases). Vocal function was examined by acoustic analysis (F0, Jitter, Shimmer, NNE, HNR), aerodynamic analysis (MPT, S/Z) and videostroboscopic examination.
  
  
  RESULTS
  For lesion mucosa ablation, hoarseness improved quickly after operation and acoustic analysis became normal. There were 18.2% decreased mucosa wave, 16.7% mild-moderate supraglottal hyperfunction. For mucosa stripping (cover layers excised), 63.3% decreased and 10.0% absented with mucosa wave, 46.7% mild-moderate supraglottal hyperfunction, glottal closure was incomplete. Acoustic analysis showed that Jitter, Shimmer, F0 different from normal(P < 0.05), HNR significantly different from normal(P < 0.01). For cordectomy: Acoustic analysis showed significantly worse than normal(P < 0.01), 61.7% mild-moderate supraglottal hyperfunction. The ipsilateral mucosa wave was absent, but 30.0% showed mucosa wave of vocal process and 13.3% with ventricular fold wave. There was little difference with or without vocalis muscle excision in acoustic analysis. To compared with mucosa stripping, the NNE, HNR, Jitter, Shimmer of cordectomy group was worse and amplitude was higher in cordectomy(P < 0.01).
  
  
  CONCLUSIONS
  Although the acoustic characteristic and vibration mode of mucosa ablation and mucosa stripping was distinct to each other, within the cover layer injured, vocal function will be good. Once the body layer is injured, vocal quality will decrease significantly.
authors.affiliation: Department of Otorhinolaryngology, Beijing Tongren Hospital, Capital University of Medical Sciences, Beijing 100730.
authors.forename: Wen
authors.initials: W
authors.lastname: Xu
authors.forename: Demin
authors.initials: D
authors.lastname: Han
authors.forename: Lizhen
authors.initials: L
authors.lastname: Hou
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Zhenkun
authors.initials: Z
authors.lastname: Yu
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Huang
authors.forename: Jingying
authors.initials: J
authors.lastname: Ye
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
mesh_terms: D000328:Adult; D005931:Glottis / Q000601:surgery; D006801:Humans; D007822:Laryngeal Neoplasms / Q000601:surgery; D053685:Laser Therapy; D008297:Male; D008866:Microsurgery; D008875:Middle Aged; D011230:Precancerous Conditions / Q000601:surgery; D014827:Vocal Cords / Q000473:pathology / Q000601:surgery*; D014833:Voice Quality