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The prevalence of vocal fold nodules in school age children
International Journal of Pediatric Otorhinolaryngology (2004) 68, 409—412
The prevalence of vocal fold nodules in school age children Mehmet Akif Kiliç*, Erdo˘ gan Okur, Ilhami Yildirim, Saime Güzelsoy Department of Otolaryngology, Medical School, Sütçü Imam University, Kahramanmara¸s, Turkey Received 21 May 2003 ; received in revised form 5 November 2003; accepted 9 November 2003
KEYWORDS School children; Vocal nodule; Voice disorders
Summary Objective: To explore the actual prevalence of vocal nodules among school age children. Methods: A total of 617 children aged from 7 to 16 years were examined. Their voices were recorded and analyzed by using acoustic analysis techniques, and vocal folds were examined by using rigid telescopic laryngoscope. The findings were noted as normal, minimal lesion, immature and mature nodules. Results: Laryngoscopic examination revealed that 430 (69.7%) of the children were normal. Of the remaining 187 children, 82 (13.3%) had minimal lesion, 88 (14.3%) immature nodule, 16 (2.6%) mature nodule and 1 (0.2%) vocal polyp. Comparisons of acoustic parameters revealed that there were no statistically significant differences between normal and minimal lesion groups, and between immature and mature nodule groups. Actual vocal nodule ratios which include both immature and mature nodule groups among whole school children were found to be 21.6% in males and 11.7% in females. © 2003 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Vocal nodule is a tissue reaction to frictional trauma between vocal folds, located at the junction of the anterior and middle thirds of them. It develops gradually as a result of chronic vocal abuse or misuse. At the beginning of the formation of a nodule, the trauma causes localized edema or submucous hemorrhage at the known location of the vocal nodules. The morphologies of vocal nodules differ in early (immature, pediatric), and late (mature) phases. Early nodules generally appear red, gelatinous and floppy, whereas the late ones white, hard and thick [1—3]. The incidence and form of vocal nodules varies with age and sex. In children, nodules are generally seen in the boys who are active and screamer, and * Corresponding author. Tel.: +90-344-221-23-37; fax: +90-344-221-23-71. E-mail address: [email protected] (M. Akif Kiliç).
male-to-female ratio is approximately 2:1 [4,5]. However, in adults, vocal nodules are found predominantly in females, particularly those who are gregarious and sing frequently [5]. Vocal nodules in pediatric age group are generally of immature type, whereas in adults generally of mature type [6,7]. Studies on the prevalence of voice disorders in children reveal large variations ranging from 1 to 23.4%, due to differences in survey methods and voice criteria used, and most surveys show 6—9% as the best estimate on the prevalence [3]. Almost all of the studies on the prevalence of vocal nodules in children have been conducted on deviant voiced ones. On the other hand, Sataloff [8] has stated that, sometimes, vocal nodules may be asymptomatic and not interfere with voice production. Therefore, we undertook this study to investigate the actual prevalence of the vocal nodule in children, on basis of physical examination by using telescopic laryngoscope.
0165-5876/$ — see front matter © 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2003.11.005
410
M. Akif Kiliç et al.
2. Materials and methods
3. Results
Seven hundred forty-seven children attending a public school that come from middle and low-middle classes in Kahramanmara¸s city center, between March 2002 and April 2002, were examined. Their ages ranged from 7 to 16 years. The study was confirmed by the Medical Ethics Committee, Faculty of Medicine, Kahramanmara¸s Sütçü Imam University. Permission was obtained from the relevant regional and district authorities and from the school authorities and parents or guardians of the children. All examinations were carried out in the quietest place in the school. For this purpose, a 90◦ angled rigid telescopic laryngoscope (Storz 8704 S) for visualization of the vocal folds, Sony MZ-R70 portable minidisc recorder and Philips SBC ME400 unidirectional electret condenser microphone for voice recording, and Multi Dimensional Voice Program (MDVP for Multi-Speech, version 2.3, Kay Elemetrics) and a PC containing Sound Blaster Live sound card for voice analysis were used. Firstly, a sustained [a] sample (at least 1 s duration) was recorded, then laryngeal examination was carried out without topical anesthesia. Complete visualization of the larynx was not obtained in 130 children due to hyperactive gag reflex, and these children were excluded from the study. The remaining 617 children, 319 (51.7%) male, 298 (48.3%) female were included in the study. During laryngoscopic examination, shape and size of the lesions and irregularities on the vocal folds were noted. Hyperemia and diffuse edema were common findings, and were not taken into consideration, because they were accepted as either physiologic or inflammatory. Three types of lesions on vocal folds were distinguished: minimal lesions, immature nodules and mature nodules. Localized edema or irregularity at the junction of anterior and middle third of the vocal folds was accepted as minimal lesion; hyperemic, edematous, fusiform lesions as immature; and fibrotic, whitish lesions as mature nodule. In the acoustic analysis of the voice samples, although more than 30 parameters were calculated, only three parameters containing fundamental frequency (F0 ), pitch perturbation quotient (PPQ) and amplitude perturbation quotient (APQ) were taken into consideration. Data were analyzed using the Epi Info 2002 statistical software (Centers for Disease Control and Prevention, Atlanta, Georgia, USA, 2002). Statistical tests of significance between groups were determined using Student’s t-test. As statistically significant level, P < 0.01 was used for all the tests.
Our study included 617 school children aged between 7 and 16 years. Of the children included in the study, 319 (51.7%) were male and 298 (48.3%) female. The frequencies according to sex and age groups are shown in Table 1. The subjects were grouped as normal, minor lesion, immature nodules and mature nodules according to laryngoscopic findings, except the one with vocal polyp. The distribution of the findings according to sex is shown in Table 2. Although some of them were asymmetric, all of the immature and mature nodules were bilateral. Comparisons of F0 values revealed no statistically significant differences among groups. Comparisons of PPQ and APQ values revealed that there were no statistically significant differences between normal and minor lesion groups, and between immature nodules and mature nodules in groups, but there were statistically significant differences between first two groups (normal and minor lesion) and second two groups (immature and mature nodules) (P < 0.01). The F0 , PPQ and APQ values for males and females according to findings can be seen in Tables 3 and 4, respectively. Table 1 Frequencies according to sex and age
groups
Age group
Male N
7—8 9—10 11—12 13—14 15—16 Total
%
60 84 91 66 18
18.8 26.3 28.5 20.7 5.6
319
100
Female
Total
N
N
%
73 74 83 64 4 298
24.5 24.8 27.9 21.5 1.3 100
%
133 158 174 130 22 617
21.6 25.6 28.2 21.1 3.6 100
Table 2 The frequencies according to sex and find-
ing groups Finding
Male N
%
Female
Total
N
N
%
%
Normal Minor lesion Immature nodules Mature nodules Vocal polyp
198 51 60
62.1 16.0 18.8
232 31 28
77.9 10.4 9.4
430 82 88
69.7 13.3 14.3
9
2.8
7
2.3
16
2.6
1
0.3
—
0.0
1
0.2
Total
319
100
298
100
617
100
Vocal fold nodules in school age children
411
Table 3 Fundamental frequencies and perturbation values according to findings (males)
Finding
F0
PPQ
APQ
Mean S.D. Mean S.D. Normal Minor lesion Immature nodules Mature nodules
Mean S.D.
241 238 244
42 37 27
0.92 1.08 1.63
0.77 3.37 0.82 3.56 1.19 4.94
1.94 1.78 2.16
247
39
1.56
0.97 5.15
1.69
Table 4 Fundamental frequencies and perturbation values according to findings (females)
Finding
F0
PPQ
APQ
Mean S.D. Mean S.D. Normal Minor lesion Immature nodules Mature nodules
Mean S.D.
274 266 267
35 40 37
0.86 0.92 1.54
0.68 2.78 0.54 2.92 0.86 4.64
1.89 1.63 1.87
279
34
1.65
0.57 4.82
1.33
4. Discussion Vocal nodules are usually bilateral and occur most commonly in children and young women. The incidence and form of vocal nodules varies with age and sex. There are several reported studies on the prevalence of voice disorders in children, however these studies are not only scarce in number but also limited to deviant voiced children. As far as we know, our work is the first study on the prevalence of vocal nodules in whole school age children based on the physical examination findings. Studies on the prevalence of voice disorders in children reveal large variations [3]. Silverman and Zimmer [9] found that 38 (23.4%) of total 162 kindergarten and school children had hoarseness, and vocal nodules were diagnosed in seven of 10 children examined by otolaryngologists. Shearer [10] stated that vocal nodules were the most frequently occurring pathologic change in children, and they were responsible for over one-half of the childhood dysphonias. Dobres et al. [4] reviewed records of 18,000 patients admitted to a children’s hospital during 3 years, and found that 731 of them had laryngeal pathologies, and 128 of them had vocal nodules. The frequency of vo-
cal nodules was 17.5% in laryngeal pathologies and 0.7% in all patients. Senturia and Wilson [11] screened school children for hoarseness, and they found voice problems in 962 (6%) children. Three hundred thirty-eight of them referred to the hospital for otolaryngologic examination. In this group, male-to-female ratio was almost 2:1, and 86.7% of them are between 6 and 11 years old. Only 92 of them were examined by indirect laryngoscopy, nodules or localized hyperplasia were observed in 63 (68.5%) children. In our study, we found the overall prevalence of vocal nodules as high as 30.2%, when minor lesions included into vocal nodule group. Because minor lesion group showed similar acoustic results with normal group, and therefore we combined these groups and reclassified the lesions as follows: normal and minor lesion groups as ‘‘normal group’’, and immature nodule and mature nodule groups as ‘‘vocal nodule group’’. According to this new classification, vocal nodule group ratios were 21.6% in males, 11.7% in females (male-to-female ratio was approximately 2:1). The overall prevalence of vocal nodules in school age children was found to be 16.9%. Stroboscopy is the most important technique in the evaluation of voice disorders, and play a role in the differential diagnosis of voice disorders. On the other hand, this technique is a time consuming and less tolerable application than simple telescopic laryngoscopy which is generally sufficient in the detection of the majority of morphologic laryngeal abnormalities. Therefore, we did not want to use stroboscopy for all children. If we were in doubt about the lesion, we further used stroboscopy in hospital setting. In conclusion, the actual prevalence of vocal nodules in school children based on the endoscopic findings was very high, and it was found as 21.6% in males and 11.7% in females.
References [1] A.E. Aronson, Clinical Voice Disorders, Third ed., Thieme, New York, 1990. [2] R. Colton, J.K. Casper, Understanding Voice Problems, Second ed., Williams and Wilkins, Baltimore, 1996. [3] D.K. Wilson, Voice Problems in Children, Third ed., Williams and Wilkins, Baltimore, 1987. [4] R. Dobres, L. Lee, J.C. Stemple, A.W. Klummer, L.W. Kretschmer, Description of laryngeal pathologies in children evaluated by otolaryngologists, J. Speech Hear. Res. 55 (1990) 526—532. [5] R.J. Prater, R.W. Swift, Manual of Voice Therapy, Pro-Ed, Austin, 1984. [6] M.N. Kotby, The Accent Method of Voice Therapy, Singular Publishing, San Diego, 1995.
412 [7] M.N. Kotby, A.G. El-Saady, A.G. Abd El-Rahman, N.H. Abd El-Nasser, A.A. Dawod, E.H. Helail, Pediatric vocal fold nodules: diagnosis profile and alternative lines of management, in: J. Sade (Ed.), Proceedings of the Third International Conference of the European Working Group for Pediatric Ot on Infections in Childhood Ear, Nose and Throat Aspects, Elsevier, Amsterdam, 1994, pp. 354—361. [8] R.T. Sataloff, Professional Voice: The Science and Art of Clinical Care, Raven Press, New York, 1991.
M. Akif Kiliç et al. [9] E.M. Silverman, C.H. Zimmer, Incidence of chronic hoarseness among school-aged children, J. Speech Hear. Disord. 40 (1975) 211—215. [10] W.H. Shearer, Diagnosis and treatment of voice disorders in school children, J. Speech Hear. Disord. 37 (1972) 215— 221. [11] B.H. Senturia, F.B. Wilson, Otolaryngologic findings in children with voice deviations, Ann. Otol. Rhinol. Laryngol. 77 (1968) 1027—1042.
The prevalence of vocal fold nodules in school age children Mehmet Akif Kiliç*, Erdo˘ gan Okur, Ilhami Yildirim, Saime Güzelsoy Department of Otolaryngology, Medical School, Sütçü Imam University, Kahramanmara¸s, Turkey Received 21 May 2003 ; received in revised form 5 November 2003; accepted 9 November 2003
KEYWORDS School children; Vocal nodule; Voice disorders
Summary Objective: To explore the actual prevalence of vocal nodules among school age children. Methods: A total of 617 children aged from 7 to 16 years were examined. Their voices were recorded and analyzed by using acoustic analysis techniques, and vocal folds were examined by using rigid telescopic laryngoscope. The findings were noted as normal, minimal lesion, immature and mature nodules. Results: Laryngoscopic examination revealed that 430 (69.7%) of the children were normal. Of the remaining 187 children, 82 (13.3%) had minimal lesion, 88 (14.3%) immature nodule, 16 (2.6%) mature nodule and 1 (0.2%) vocal polyp. Comparisons of acoustic parameters revealed that there were no statistically significant differences between normal and minimal lesion groups, and between immature and mature nodule groups. Actual vocal nodule ratios which include both immature and mature nodule groups among whole school children were found to be 21.6% in males and 11.7% in females. © 2003 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Vocal nodule is a tissue reaction to frictional trauma between vocal folds, located at the junction of the anterior and middle thirds of them. It develops gradually as a result of chronic vocal abuse or misuse. At the beginning of the formation of a nodule, the trauma causes localized edema or submucous hemorrhage at the known location of the vocal nodules. The morphologies of vocal nodules differ in early (immature, pediatric), and late (mature) phases. Early nodules generally appear red, gelatinous and floppy, whereas the late ones white, hard and thick [1—3]. The incidence and form of vocal nodules varies with age and sex. In children, nodules are generally seen in the boys who are active and screamer, and * Corresponding author. Tel.: +90-344-221-23-37; fax: +90-344-221-23-71. E-mail address: [email protected] (M. Akif Kiliç).
male-to-female ratio is approximately 2:1 [4,5]. However, in adults, vocal nodules are found predominantly in females, particularly those who are gregarious and sing frequently [5]. Vocal nodules in pediatric age group are generally of immature type, whereas in adults generally of mature type [6,7]. Studies on the prevalence of voice disorders in children reveal large variations ranging from 1 to 23.4%, due to differences in survey methods and voice criteria used, and most surveys show 6—9% as the best estimate on the prevalence [3]. Almost all of the studies on the prevalence of vocal nodules in children have been conducted on deviant voiced ones. On the other hand, Sataloff [8] has stated that, sometimes, vocal nodules may be asymptomatic and not interfere with voice production. Therefore, we undertook this study to investigate the actual prevalence of the vocal nodule in children, on basis of physical examination by using telescopic laryngoscope.
0165-5876/$ — see front matter © 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2003.11.005
410
M. Akif Kiliç et al.
2. Materials and methods
3. Results
Seven hundred forty-seven children attending a public school that come from middle and low-middle classes in Kahramanmara¸s city center, between March 2002 and April 2002, were examined. Their ages ranged from 7 to 16 years. The study was confirmed by the Medical Ethics Committee, Faculty of Medicine, Kahramanmara¸s Sütçü Imam University. Permission was obtained from the relevant regional and district authorities and from the school authorities and parents or guardians of the children. All examinations were carried out in the quietest place in the school. For this purpose, a 90◦ angled rigid telescopic laryngoscope (Storz 8704 S) for visualization of the vocal folds, Sony MZ-R70 portable minidisc recorder and Philips SBC ME400 unidirectional electret condenser microphone for voice recording, and Multi Dimensional Voice Program (MDVP for Multi-Speech, version 2.3, Kay Elemetrics) and a PC containing Sound Blaster Live sound card for voice analysis were used. Firstly, a sustained [a] sample (at least 1 s duration) was recorded, then laryngeal examination was carried out without topical anesthesia. Complete visualization of the larynx was not obtained in 130 children due to hyperactive gag reflex, and these children were excluded from the study. The remaining 617 children, 319 (51.7%) male, 298 (48.3%) female were included in the study. During laryngoscopic examination, shape and size of the lesions and irregularities on the vocal folds were noted. Hyperemia and diffuse edema were common findings, and were not taken into consideration, because they were accepted as either physiologic or inflammatory. Three types of lesions on vocal folds were distinguished: minimal lesions, immature nodules and mature nodules. Localized edema or irregularity at the junction of anterior and middle third of the vocal folds was accepted as minimal lesion; hyperemic, edematous, fusiform lesions as immature; and fibrotic, whitish lesions as mature nodule. In the acoustic analysis of the voice samples, although more than 30 parameters were calculated, only three parameters containing fundamental frequency (F0 ), pitch perturbation quotient (PPQ) and amplitude perturbation quotient (APQ) were taken into consideration. Data were analyzed using the Epi Info 2002 statistical software (Centers for Disease Control and Prevention, Atlanta, Georgia, USA, 2002). Statistical tests of significance between groups were determined using Student’s t-test. As statistically significant level, P < 0.01 was used for all the tests.
Our study included 617 school children aged between 7 and 16 years. Of the children included in the study, 319 (51.7%) were male and 298 (48.3%) female. The frequencies according to sex and age groups are shown in Table 1. The subjects were grouped as normal, minor lesion, immature nodules and mature nodules according to laryngoscopic findings, except the one with vocal polyp. The distribution of the findings according to sex is shown in Table 2. Although some of them were asymmetric, all of the immature and mature nodules were bilateral. Comparisons of F0 values revealed no statistically significant differences among groups. Comparisons of PPQ and APQ values revealed that there were no statistically significant differences between normal and minor lesion groups, and between immature nodules and mature nodules in groups, but there were statistically significant differences between first two groups (normal and minor lesion) and second two groups (immature and mature nodules) (P < 0.01). The F0 , PPQ and APQ values for males and females according to findings can be seen in Tables 3 and 4, respectively. Table 1 Frequencies according to sex and age
groups
Age group
Male N
7—8 9—10 11—12 13—14 15—16 Total
%
60 84 91 66 18
18.8 26.3 28.5 20.7 5.6
319
100
Female
Total
N
N
%
73 74 83 64 4 298
24.5 24.8 27.9 21.5 1.3 100
%
133 158 174 130 22 617
21.6 25.6 28.2 21.1 3.6 100
Table 2 The frequencies according to sex and find-
ing groups Finding
Male N
%
Female
Total
N
N
%
%
Normal Minor lesion Immature nodules Mature nodules Vocal polyp
198 51 60
62.1 16.0 18.8
232 31 28
77.9 10.4 9.4
430 82 88
69.7 13.3 14.3
9
2.8
7
2.3
16
2.6
1
0.3
—
0.0
1
0.2
Total
319
100
298
100
617
100
Vocal fold nodules in school age children
411
Table 3 Fundamental frequencies and perturbation values according to findings (males)
Finding
F0
PPQ
APQ
Mean S.D. Mean S.D. Normal Minor lesion Immature nodules Mature nodules
Mean S.D.
241 238 244
42 37 27
0.92 1.08 1.63
0.77 3.37 0.82 3.56 1.19 4.94
1.94 1.78 2.16
247
39
1.56
0.97 5.15
1.69
Table 4 Fundamental frequencies and perturbation values according to findings (females)
Finding
F0
PPQ
APQ
Mean S.D. Mean S.D. Normal Minor lesion Immature nodules Mature nodules
Mean S.D.
274 266 267
35 40 37
0.86 0.92 1.54
0.68 2.78 0.54 2.92 0.86 4.64
1.89 1.63 1.87
279
34
1.65
0.57 4.82
1.33
4. Discussion Vocal nodules are usually bilateral and occur most commonly in children and young women. The incidence and form of vocal nodules varies with age and sex. There are several reported studies on the prevalence of voice disorders in children, however these studies are not only scarce in number but also limited to deviant voiced children. As far as we know, our work is the first study on the prevalence of vocal nodules in whole school age children based on the physical examination findings. Studies on the prevalence of voice disorders in children reveal large variations [3]. Silverman and Zimmer [9] found that 38 (23.4%) of total 162 kindergarten and school children had hoarseness, and vocal nodules were diagnosed in seven of 10 children examined by otolaryngologists. Shearer [10] stated that vocal nodules were the most frequently occurring pathologic change in children, and they were responsible for over one-half of the childhood dysphonias. Dobres et al. [4] reviewed records of 18,000 patients admitted to a children’s hospital during 3 years, and found that 731 of them had laryngeal pathologies, and 128 of them had vocal nodules. The frequency of vo-
cal nodules was 17.5% in laryngeal pathologies and 0.7% in all patients. Senturia and Wilson [11] screened school children for hoarseness, and they found voice problems in 962 (6%) children. Three hundred thirty-eight of them referred to the hospital for otolaryngologic examination. In this group, male-to-female ratio was almost 2:1, and 86.7% of them are between 6 and 11 years old. Only 92 of them were examined by indirect laryngoscopy, nodules or localized hyperplasia were observed in 63 (68.5%) children. In our study, we found the overall prevalence of vocal nodules as high as 30.2%, when minor lesions included into vocal nodule group. Because minor lesion group showed similar acoustic results with normal group, and therefore we combined these groups and reclassified the lesions as follows: normal and minor lesion groups as ‘‘normal group’’, and immature nodule and mature nodule groups as ‘‘vocal nodule group’’. According to this new classification, vocal nodule group ratios were 21.6% in males, 11.7% in females (male-to-female ratio was approximately 2:1). The overall prevalence of vocal nodules in school age children was found to be 16.9%. Stroboscopy is the most important technique in the evaluation of voice disorders, and play a role in the differential diagnosis of voice disorders. On the other hand, this technique is a time consuming and less tolerable application than simple telescopic laryngoscopy which is generally sufficient in the detection of the majority of morphologic laryngeal abnormalities. Therefore, we did not want to use stroboscopy for all children. If we were in doubt about the lesion, we further used stroboscopy in hospital setting. In conclusion, the actual prevalence of vocal nodules in school children based on the endoscopic findings was very high, and it was found as 21.6% in males and 11.7% in females.
References [1] A.E. Aronson, Clinical Voice Disorders, Third ed., Thieme, New York, 1990. [2] R. Colton, J.K. Casper, Understanding Voice Problems, Second ed., Williams and Wilkins, Baltimore, 1996. [3] D.K. Wilson, Voice Problems in Children, Third ed., Williams and Wilkins, Baltimore, 1987. [4] R. Dobres, L. Lee, J.C. Stemple, A.W. Klummer, L.W. Kretschmer, Description of laryngeal pathologies in children evaluated by otolaryngologists, J. Speech Hear. Res. 55 (1990) 526—532. [5] R.J. Prater, R.W. Swift, Manual of Voice Therapy, Pro-Ed, Austin, 1984. [6] M.N. Kotby, The Accent Method of Voice Therapy, Singular Publishing, San Diego, 1995.
412 [7] M.N. Kotby, A.G. El-Saady, A.G. Abd El-Rahman, N.H. Abd El-Nasser, A.A. Dawod, E.H. Helail, Pediatric vocal fold nodules: diagnosis profile and alternative lines of management, in: J. Sade (Ed.), Proceedings of the Third International Conference of the European Working Group for Pediatric Ot on Infections in Childhood Ear, Nose and Throat Aspects, Elsevier, Amsterdam, 1994, pp. 354—361. [8] R.T. Sataloff, Professional Voice: The Science and Art of Clinical Care, Raven Press, New York, 1991.
M. Akif Kiliç et al. [9] E.M. Silverman, C.H. Zimmer, Incidence of chronic hoarseness among school-aged children, J. Speech Hear. Disord. 40 (1975) 211—215. [10] W.H. Shearer, Diagnosis and treatment of voice disorders in school children, J. Speech Hear. Disord. 37 (1972) 215— 221. [11] B.H. Senturia, F.B. Wilson, Otolaryngologic findings in children with voice deviations, Ann. Otol. Rhinol. Laryngol. 77 (1968) 1027—1042.