[Relaxation laryngoplasty in the management of mutational falsetto].

Objective: To observe the result of relaxation laryngoplasty in the management of mutational falsetto.

Methods: The thyroplasty type 3 was applied and improved (the saturation was improved in the traditional operation, which the thyroid cartilage stick was cut off and overlapped without saturation in improved group 1, while the thyroid cartilage stick was not cut off and overlapped inward without saturation in improved group 2) in 30 adult patients who failed in voice modification. Preoperative and postoperative fundamental frequency (F0), normalised noise energy (NNE) and reading essay were compared.

Results: F0 dropped significantly from the preoperative mean of (276.5 +/- 46.7) Hz [see equation in text] to the postoperative mean of (127.5 +/- 32.1) Hz in one month (t = 13.68, P < 0.001), while the NNE dropped significantly from the preoperative mean of (-10.9 +/- 4.9) dB to the postoperative mean of (-7.7 +/- 4.1) dB, the difference was statistically significant (t = 4.07, P < 0.001). In the three kinds of operation, the postoperative F0 in the improved group 1 dropped most significantly (compared with traditional operation group t = 2.64, P< 0.05). The postoperative NNE in the improved group 2 increased minimally. The difference was not significant statistically compared with other two kinds of operations (P > 0.05). The pitch dropped in all cases during reading aloud and conversation, while the voice breaks was disappeared.

Conclusions: Relaxation laryngoplasty was proved to be an efficient procedure in the surgical management of mutational falsetto.It was a preferable option for the patients who failed in voice modification. The improved operation profited to recover natural intonation and lighten the hoarseness due to glottic incompetence.