Release: September 9, 2001
Contact: Kenneth Satterfield(703) 519-1563[email protected]303-228-8460 (9/7-9/12)
UVULOPALATOPHARYNGOPLASTY (UPPP) FOUND NOT TO CAUSE POSTOPERATIVE NASALITY IN THE VOICE
New research findings minimize concerns that this common surgical treatment for sleep apnea will permanently alter the voice.
Denver, CO -- Uvulopalatopharyngoplasty (UPPP) is a surgical procedure that is increasingly used in the treatment of obstructive sleep apnea syndrome (OSAS). UPPP involves removal and tightening of redundant oropharyngeal tissue. Consequently, patients have concerns regarding the potential effect of procedure's effect upon voice and speech.
This is not an unreasonable concern. The physiology of voice production begins with sounds produced by the vibrating vocal folds of the larynx. The pharynx, oral cavity, and nasal cavity act as a series of interconnected resonators, which attenuate some frequencies and enhance other frequencies. Vocal tract shape is dynamically controlled in the generation of voice. Palatal structure and motion is an important component of vocal tract shape. The surgical treatment of OSAS with UPPP includes removal of the uvula and a portion of the soft palate. The lateral oropharyngeal walls are also tightened after removal of the tonsils and other redundant tissues. Anatomical changes associated with UPPP could conceivably result in voice and speech changes
The largest prospective study up to now that assess UPPP effect on the voice recorded preoperative and postoperative voice in 32 patients undergoing the procedure. The average postoperative analysis interval was 5.4 months. The researchers in that study concluded that UPPP does not produce significant voice or speech changes with regard to fundamental frequency, reading rate, long-term average spectra, and listener judgments of preoperative and postoperative pairs.
The limited data on the effect of UPPP upon voice was a key reason that a group of Pennsylvania medical researchers set out to assess if hypernasality of voice is a potential complication of uvulopalatopharyngoplasty (UPPP) for obstructive sleep apnea.
The authors of the study, "The Effect of Uvulopalatopharyngoplasty Upon the Nasality of Voice" are J. Scott Greene, MD, Terrence E. Zipfel, MD, Mark Harlor, M.Ed., CCC-SLP, all from the Departments of Otolaryngology -- Head & Neck Surgery and Speech Pathology, Geisinger Medical Center Danville, PA. Their results were presented at the American Academy of Otolaryngology--Head and Neck Surgery Foundation Annual Meeting/OTO EXPO, being held September 9-12, at the Colorado Convention Center, Denver, CO.
Methodology: Fifteen patients undergoing a UPPP had their voice evaluated on a preoperative, onemonth postoperative and six-month postoperative basis. Excluded from the study were patients undergoing concurrent surgical procedures other than tonsillectomy. Surgery was performed at a single teaching hospital using standard techniques.
Vocal parameters assessed included nasality, maximum phonation time, speaking fundamental frequency, frequency perturbation, intensity level and psychoacoustic analysis (consisting of a single certified speech-language pathologist in the Clinical Voice Laboratory at the Geisinger Medical Center rating each subject's voice in conversation as it relates to the parameters of pitch, quality, rate, resonance, and loudness). Acoustic analysis was accomplished with the Kay Elemetrics Visi-Pitch 6095/6097 system. The Nasometer (Model 6200) by Kay Elemetrics, which measures and analyzes the amount of nasal acoustic energy in a person's speech, was used for determining nasality.
Results: Compared to preoperative levels, nasality decreased at post-operative assessments (one and six months). Two patients had abnormally elevated nasality at the one-month assessment. Both returned to normal at the six-month assessment. There were no significant changes in maximum phonation time, fundamental frequency or intensity level between preoperative assessments and either of the two postoperative assessments. Psychoacoustic analysis revealed mild hypernasality in one patient at the one-month assessment. This patient returned to normal at the six-month assessment. No patients exhibited hypernasality at the six-month assessment.
After six months, the subjects were re-evaluated. On average, percent nasality changed by -1.5 percent, and none of the subjects were above the normal threshold of 15 percent. This difference was not statistically significant. Similarly, maximum phonation changed by --2.4 sec; intensity level changed by 0.1 dB; and 11 subjects had normal psychoacoustic analysis; none were statistically significant. However, after six months, change in percent frequency pertubation was statistically significant. This decrease in perturbation represents clinical improvement in voice quality.
Fundamental frequency was analyzed separately for males and females. After six months, females had a statistically significant decrease in fundamental frequency, and males had a statistically significant increase in fundamental frequency. These small statistical changes in speaking fundamental frequency were deemed not clinically significant.
Conclusion: The researchers believe their findings support the low-incidence of hypernasality and other common speech/voice parameters seen after UPPP. Specifically, (1) there is no evidence of a statistically significant change in nasality, maximum phonation time, intensity level, or psychoacoustic analysis; (2) frequency pertubation deceased after 6-months; (3) there is no evidence of clinically significant change in fundamental frequency. Preoperative counseling of surgical candidates can include assurance that the risk of UPPP altering voice is very low.
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