Foroughian, Mahdi M.D.; Khazaeni, Kamran M.D.; Haghi, Mohsen Rajati M.D.; Jahangiri, Nader Ph.D.; Mashhadi, Leila M.D.; Bakhshaee, Mehdi M.D.
Rhinoplasty is one of the most popular cosmetic procedures in Iran. Because a large number of patients undergo this procedure, concerns such as changes in respiratory and olfactory functions and effect on the quality of life have been raised. Numerous advancements in rhinoplasty techniques and its long-term results have made rhinoplasty a popular operation. However, in recent years, surgeons have witnessed a shift toward conservative techniques for saving nasal functions.
Voice production is a complex task that, according to the source-filter theory of voice production, begins with an expiratory effort from the lungs. This expiratory force makes true vocal cords or another constriction in the vocal tract vibrate and produce sound. The produced sound is transmitted to the resonator vocal tract above, and the chosen frequencies become dominant, called formants.1
One of the components of this resonator system (i.e., the filter) is our nasal cavity, which is narrowed by rhinoplasty osteotomies. In theory, the acoustic sounds traveling through the nasal cavity face a greater depth of absorbing tissue after rhinoplasty; therefore, we expect changes in the amplitude and the frequency of these sounds following rhinoplasty.
We recently noticed patients who use their voice professionally asking whether rhinoplasty would change their voice. Thus, we thought it would be important and interesting to assess the potential effect of rhinoplasty on voice characteristics. We also tried to verify whether any change in voice characteristics is noticeable by the patients themselves or other listeners. In the present study, we analyzed voice characteristics before and after rhinoplasty surgery, and we compared the results to see the potential effect of rhinoplasty on voice characteristics.
PATIENTS AND METHODS
This study was performed between April of 2010 and November of 2011 in 27 patients who were candidates for rhinoplasty surgery at Qaem and Imam Reza hospitals, Mashhad, Iran. Patients’ ages ranged from 18 and 45 years, with a mean age of 24.22 ± 6.16 years. Twenty-two patients (81 percent) were female and five (19 percent) were male. Of our patients, 22 percent used their voice professionally. Each patient signed an informed consent to participate in the study, and the study protocol was approved by the Mashhad University of Medical Sciences Ethic Committee.
We excluded patients from the study if concurrent septoplasty, turbinectomy, or functional endoscopic sinus surgery was required or if patients had another recurring disease influencing the cross-sectional area of the nose and sinuses, such as untreated allergies. We postponed the test if a patient had an upper respiratory tract infection. We tried to select patients with similar aesthetic problems. We excluded patients with large humps and those who needed spreader grafts during the surgery. We also excluded patients with a saddle nose, and all revision cases were excluded as well.
The patients were given Voice Handicap Index questionnaires, which are widely used for voice self-assessment. We obtained a medical history for and performed a physical examination on all patients. Next, patients were referred to our speech therapy clinic, where they were given phonemes, words, and sentences—chosen by our linguist consultant—before and after surgery. The setting for speech sampling was standard and the same for all patients. We used a multimedia microphone (Genius 750, Dong Guan, China) positioned 10 cm away from patients.
Because the Persian language does not have nasal vowels, we used the nasal consonants “m” and “n” and vowels with two nasal consonants on each side to determine nasal resonance characteristics.
The surgical procedure was performed by two surgeons using the same protocol, starting with an open or closed approach. We performed lateral cephalic trim and used interdomal and transdomal sutures for tip plasty. In addition, we used a collumellar strut graft in all patients. The dorsal hump was reduced by conservative osteotomy. We performed low to low-external lateral osteotomies afterward.
After 5 months, if the rhinoplasty results were favorable and the postoperative period revealed no complications, the speech analysis tests were repeated using the same setting and technique. We used Voice Handicap Index questionnaires, perceptual analysis, and acoustic analysis in this study.
Voice Handicap Index Questionnaire
The Voice Handicap Index questionnaire has three subscales: a functional subscale, a physical subscale, and an emotional subscale. Patients rate each question on a five-point scale; the answer to each question reflects the frequency of occurrence, and higher total scores reflects greater handicap.1 The Voice Handicap Index has 10 items in each of its three domains (i.e., emotional, physical, and functional). The first domain (functional subscale) comprises statements that describe the effect of a patient’s voice on his or her daily activities. The second domain (emotional subscale) shows the person’s affective responses to his or her voice disorder. The third domain (physical subscale) comprises statements that relate to the patient’s perception of laryngeal discomfort or the patient’s perception of voice output characteristics. The Voice Handicap Index can be used to assess all types of voice disorders.2 We used this questionnaire before and after surgery to compare the changes after rhinoplasty.
We performed a perceptual analysis on the voice samples before and after surgery. Six trained, blinded listeners reviewed the voice samples and rated the perceived nasality of the voice on a visual analog scale from 0 to 100.
For acoustic analysis, we used the Praat for Windows version 5.3.44 software package (Phonetic Sciences, Univesity of Amsterdam, Amsterdam, The Netherlands) to measure frequency, bandwidth, and intensity of selected consonants and vowels in selected sentences.
We performed all statistical analyses using the SPSS for Windows version 16 software package (SPSS Inc., Chicago, Ill.). Data are expressed as mean ± SD (for parameters with a normal distribution) or median and interquartile range (for nonnormally distributed data).
Because the value of the Voice Handicap Index functional and physical subscales was not normally distributed, we used the square root to convert it to normally distributed data, while emotional Voice Handicap Index values remained nonnormally distributed. We used paired t tests and the Wilcoxon comparison tests to compare values before and after the intervention.
Voice Handicap Index Questionnaire
We separately scored and compared each subscale of the Voice Handicap Index questionnaire. Our results indicate that scores on the index were higher 5 months after surgery compared with baseline values before surgery (p = 0.04).
The mean value of the functional subscale of the Voice Handicap Index (first 10 questions) results showed no significant difference after the operation compared with the presurgical value (p = 0.705).
The mean values of the physical and emotional subscales of the Voice Handicap Index (second 10 questions and third 10 questions, respectively) were significantly higher after the operation (p = 0.018 and p = 0.030, respectively).
These results are summarized in Table 1.
Perceptual analysis by trained listeners showed that hyponasality increased significantly after surgery (p < 0.001). These values are summarized in Table 2.
The results of the acoustic analysis of voice samples of the nasal consonant “m” in “man,” “n” in “namak,” and /a/ in “man” in selected sentences are summarized in Table 3. Moreover, a sample analysis of “m” in “man” and “n” in “namak” before surgery from one patient is shown in Figure 1 and Table 4.
We aimed to analyze voice changes after rhinoplasty to determine whether rhinoplasty can change vocal characteristics due to the change in the nasal cavity. To the best of our knowledge, this is the first published study to investigate vocal changes after rhinoplasty. We used three modalities to evaluate voice in this study: self-assessment, trained listener assessment, and software-based assessment.
Other studies have shown a relationship between Voice Handicap Index score and vocal characteristics of the patient.3–6 Therefore, we can use the index score to monitor changes in the characteristics of the voice after surgery. Mora and colleagues showed a mean index score decrease from 98 to 22 after tonsillectomy, indicating an improvement in voice characteristics.7 Behrman and colleagues used the Voice Handicap Index score for upper airway surgery and showed no clinical or statistical change in the score after surgery.8
We found a statistically significant difference in the data derived from Voice Handicap Index questionnaires before and after surgery (p = 0.004) in which patients had higher (worse) Voice Handicap Index scores after surgery. Analyzing the three subscales of the questionnaire separately showed a statistically significant difference in the physical and emotional component after surgery (p = 0.018 and p = 0.03, respectively), but no statistically significant change in the Voice Handicap Index score in the functional subscale.
The increased Voice Handicap Index score indicates that voice characteristics change after rhinoplasty, suggesting that patients may notice voice changes after surgery. However, it is important to mention that the change is confined to the emotional and physical subscales of the questionnaire and that the Voice Handicap Index functional subscale remains unchanged. We can therefore assume that these changes do not alter patients’ functional abilities.
There are studies using trained listeners to evaluate voice changes. Greene and colleagues studied the effects of uvulopalatopharyngoplasty on the nasality of voice and perceived no change in nasality 6 months after the operation.9 In another study, Chen and Metson showed an increase in hyponasality of high vowel /i/ in “beep” perceived by trained phoneticians after sinus surgery.10
In our study, a significant increase in hyponasality was observed as assessed by blinded trained listeners using a visual analog scale (p < 0.001). This observed increase in hyponasality perception demonstrates that the change in the patients’ voices is perceptible to trained listeners but does not address whether this change is apparent in everyday life and in routine conversations.
Acoustic analysis results showed a statistically significant increase in the first and second nasal murmurs frequency for the phonemes “m” and “n” after rhinoplasty. This was also true for the first and second formant frequency for the phoneme /a/ when pronounced between two nasal consonants. The amplitude of these formants and nasal murmurs showed a statistically significant decrease. The formant bandwidth analysis showed that for the phonemes “m,” the first and second nasal murmurs bandwidth, and for the phoneme “n,” the first nasal murmur bandwidth had a statistically significant increase. For the phoneme “a,” there was no statistically significant change in the formant bandwidth.
Chen and Metson showed increasing nasality of the phoneme /æ/ in the word “bad” and decreasing nasality of /i/ in the word “beep.”10 These findings show that in sinus operations, clearing of obstructive tissue in the sinunasal passage and changing the surface area of these passages results in changes to the resistance to airflow and makes consistent and predictable changes in voice.
Guyuron studied nasal osteotomy effects on the nasal airway.11 Length of the nasal bones, degree of nasal bone repositioning, inferior turbinate position after surgery, and type of osteotomy were definite contributing factors for nasal airway narrowing in his study.
We propose that a possible mechanism for the shift in formant frequencies and decrease in the perceived amplitude could be due to lateral and medial osteotomies, which result in medialization of the lateral nasal wall. This leads to a decreased cross-sectional area in the nasal cavity and an increase in the resistance to the sound wave passing through the nasal cavity. This change in the resonator chamber figure will result in a shift in formant frequencies and a decrease in the perceived amplitude.
Rhinoplasty candidates are a heterogeneous group with different aesthetic needs and different surgical requirements. We tried to include patients with similar problems to reduce the heterogeneity. All 27 of our patients needed reduction rhinoplasty, with all revision cases or augmentation rhinoplasty cases excluded. We decided to analyze voice changes 5 months after surgery because with longer follow-up periods, the number of patients cooperating decreases. Further studies can follow more patients with similar surgical needs for longer periods of time to evaluate changes after different methods of rhinoplasty surgery.
Rhinoplasty results in a narrowed nasal cavity because of lateral osteotomies. Changes in the surface area of the nasal cavity may increase airflow resistance and cause an increase in sound absorption and a decrease in the passing sound amplitude. Voice Handicap Index scores, and specifically the physical and emotional components, show that the voice changes are somewhat perceived by the patients. In contrast, the Voice Handicap Index score functional subscale remained unchanged, suggesting that these changes do not interfere with patients’ lives. Trained listeners can perceive increased nasality after surgery, while acoustic analysis shows significant changes in the frequency and amplitude of nasal murmurs and formants.
The authors thank Mr. Tayarani and Mrs. Zareyee for their valuable help and Dr. Amir Ali Rahsepar for editing this article. The authors also thank their patients for their cooperation. This study was the result of Mahdi Foroughian thesis which was supported financially by Mashhad University of Medical Sciences, Iran.
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