- Email: [email protected]
Arytenoid asymmetry in opera singers
G Model ANORL-812; No. of Pages 4
ARTICLE IN PRESS European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2018) xxx–xxx
Available online at
ScienceDirect www.sciencedirect.com
Original article
Arytenoid asymmetry in opera singers P. Clarós ∗ , A. Clarós-Pujol , A. Clarós Oto-Rhino-Laryngologie, Clínica Clarós, c/. Los Vergós, 31, 08017 Barcelona, Spain
a r t i c l e
i n f o
Keywords: Arytenoid asymmetry Vocal symptoms Opera singers
a b s t r a c t Introduction: Otolaryngologists commonly observe asymmetrical movements of the arytenoid cartilages, but few authors have described the clinical implications of this asymmetry, especially in singers. Objectives: The aim of this study was to determine the epidemiological and clinical characteristics of arytenoid asymmetry in adduction in a group of healthy opera singers and to evaluate the impact of this asymmetry on the voice. Patients and methods: The medical charts and laryngeal video recordings of 245 healthy opera singers were retrospectively reviewed. Arytenoid asymmetry was defined in relation to the position of the corniculate cartilages, cuneiform cartilages and aryepiglottic angle. Results: The subjects had a mean age of 38.54 years (range: 18 to 85 years) and presented a male-tofemale sex ratio of 1.02. About 5% of subjects had a history of smoking. The most common vocal symptoms were occasional dysphonia (4%), followed by vocal fatigue (2%) and pharyngeal dryness (2%). Arytenoid asymmetry was slightly more common in males (50.6%) and predominantly affected the right side (64.5%). The most common form of asymmetry was cuneiform asymmetry (37.5%), followed by aryepiglottic angle asymmetry in 33.1% of cases and corniculate asymmetry in 29.4% of cases. Mild asymmetry was observed in the majority of cases. No correlation was observed between arytenoid asymmetry and vocal symptoms. Conclusion: Almost one out of two singers was likely to present arytenoid asymmetry in adduction. The presence of this asymmetry does not appear to be correlated with any vocal symptoms. © 2018 Elsevier Masson SAS. All rights reserved.
1. Introduction The larynx plays an essential role in breathing, phonation and deglutition. It is composed of several cartilages connected by joints, ligaments, membranes and muscles. The key element for maintenance of laryngeal integrity and function is an intact and mobile cricoarytenoid joint. Arytenoid adduction is characterized by anteroposterior tilting on the long axis of the arytenoid cartilages, lateral sliding and a small degree of rotation [1]. It is often attributed to asymmetry of the laryngeal cartilages, as already reported by several authors [2–5]. In their radiological study of patients presenting with voice disorders, Friedrich et al. [2–4] showed that asymmetry was common in dysphonic subjects and was related to vocal symptoms. Hirano et al. [5] reported similar results by showing that the anteroposterior dimensions of the thyroid cartilage were longer on the left side than on the right side. The prevalence of arytenoid asymmetry varies as a function of the type of asymmetry and the patient’s age and sex. In their study of 109 subjects not presenting any voice disorders, Lindestad et al.
[6] reported a 70% incidence of arytenoid asymmetry. The most frequent type of asymmetry (66% of patients), accounting for 92% of all cases of asymmetry observed, consisted of lateral differences in the anteroposterior position of the corniculate or cuneiform cartilages [6]. These authors also reported that asymmetry was more frequent in older people and singers. These results corroborate those reported by Lacina [7] in a cohort of Milanese opera singers. Using indirect mirror laryngoscopy, Lacina [7] reported a high incidence of arytenoid asymmetry in singers compared to non-singers and attributed these results to the fact that singers had to more accurately compensate for anatomical variants of laryngeal cartilages in order to more effectively align their vocal folds when singing. Very few data on arytenoid asymmetry in adduction are available at the present time. The objective of this study was to determine the epidemiological and clinical characteristics of arytenoid asymmetry in a series of opera singers and to look for a possible correlation between arytenoid asymmetry and vocal symptoms. 2. Materials and methods
∗ Corresponding author. E-mail address: [email protected] (P. Clarós).
We conducted a retrospective, descriptive study on a series of 250 opera singers (professional singers, amateur singers and
https://doi.org/10.1016/j.anorl.2018.08.014 1879-7296/© 2018 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Clarós P, et al. Arytenoid asymmetry in opera singers. European Annals of Otorhinolaryngology, Head and Neck diseases (2018), https://doi.org/10.1016/j.anorl.2018.08.014
G Model ANORL-812; No. of Pages 4 2
ARTICLE IN PRESS P. Clarós et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2018) xxx–xxx
Fig. 1. Normal larynx.
Fig. 2. Various types of asymmetry: a: right corniculate asymmetry due to overlap; b: right cuneiform asymmetry in an anterior position; c: aryepiglottic angle asymmetry; d: left cuneiform asymetry.
singing students) attending our otorhinolaryngology clinic in Barcelona, Spain. Inclusion criteria were all patients over the age of 18 years presenting arytenoid asymmetry. The patients’ medical charts and video recordings were examined. All patients with a history of surgery or laryngeal disease, such as nodules, polyps, cysts and other tumours, were excluded from this study. All patients were examined by an experienced otorhinolaryn® gologist using a Karl Storz 90◦ rigid endoscope connected to a camera. Videos were recorded during phonation and the various types of arytenoid asymmetry in adduction observed were listed. Arytenoid asymmetry was classified into 3 types according to the position of the corniculate and cuneiform cartilages, and the aryepiglottic angle (angle between the aryepiglottic cartilage and the epiglottis) compared to a normal larynx (Figs. 1 and 2).
Corniculate asymmetry was defined by the presence of prominent corniculate cartilages or in an anterior position compared to the contralateral side. Cuneiform asymmetry was defined by the anterior position of the cuneiform cartilages compared to the contralateral side. Aryepiglottic angle asymmetry was noted when a more acute angle was observed on one side compared to the opposite side. The various degrees of asymmetry were classified into three groups: mild, moderate and severe. The side of asymmetry was also specified (right or left). The following variables were studied: age, sex, type, laterality and degree of arytenoid asymmetry observed in each subject. A history of smoking and vocal symptoms, such as dysphonia, cough, hoarseness or vocal fatigue, were also investigated.
Please cite this article in press as: Clarós P, et al. Arytenoid asymmetry in opera singers. European Annals of Otorhinolaryngology, Head and Neck diseases (2018), https://doi.org/10.1016/j.anorl.2018.08.014
G Model
ARTICLE IN PRESS
ANORL-812; No. of Pages 4
P. Clarós et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2018) xxx–xxx Table 1 Epidemiological characteristics of the singers. Number of singers Sex ratio (male/female) Age Mean age Range Smokers Associated symptoms Occasional dysphonia Pharyngeal dryness Vocal fatigue
245 1.02 38.54 years 18–85 years 5% 4% 2% 2%
Table 2 Prevalence of arytenoid asymmetry (%). Arytenoid asymmetry Right asymmetry Left asymmetry Women Men
64.5 35.5 49.4 50.6
Table 3 Types of arytenoid asymmetry (%). Cuneiform asymmetry Mild Moderate Severe Corniculate asymmetry Mild Moderate Severe Aryepiglottic angle asymmetry Mild Moderate Severe
37.5 67.4 25 7.6 29.4 61.1 34.7 4.2 33.1 38.3 55.5 6.2
3. Results 3.1. Epidemiological data A total of 245 singers with a mean age of 38.54 years (range: 18 to 85 years) and an M/F sex ratio of 1.02 (124 men and 121 women) were included in this study. About 5% of subjects reported a history of smoking. The symptoms associated with arytenoid asymmetry were occasional dysphonia (4%), pharyngeal dryness (2%) and vocal fatigue (2%) (Table 1). 3.2. Arytenoid asymmetry In this study, arytenoid asymmetry was more frequent on the right side (64.5%) than on the left side (35.5%) and was slightly more frequent in men (50.6%) than in women (49.4%) (Table 2). The type of asymmetry most commonly observed was cuneiform asymmetry in 37.5% of cases, followed by aryepiglottic angle asymmetry in 33.1% of cases and finally corniculate asymmetry in 29.4% of cases. Asymmetry was considered to be mild in the majority of cases (Table 3).
3
different positions, dimensions and shapes. However, arytenoid asymmetry appears to be more frequent in abduction than in phonation. When arytenoid asymmetry is observed in adduction, otorhinolaryngologists are often unable to distinguish between normal and pathological appearances. Despite the importance of the cricoarytenoid joint, very few studies have evaluated the prevalence of arytenoid asymmetry in adduction, its clinical impact on phonation and its association with vocal symptoms, especially in singers [5–7]. A slight male predominance of arytenoid asymmetry (M/F sex ratio: 1.02) was observed in this study. Hirano et al. [5] also reported no particular anatomical difference between the two sexes in their series. On the other hand, Hamdan et al. [8] and Husseini et al. [9] reported a marked male predominance of arytenoid asymmetry in their respective series of singers. Anatomical studies have shown a higher prevalence of laryngeal asymmetry in older people [5]. The mean age of the patients in this series was 38.54 years (range: 18 to 85 years), while Hamdan et al. [8] and Husseini et al. [9] reported a mean age of 23.4 years and 24 years in their respective series. This difference can be explained by the fact that their subjects were younger with an age range of 15 to 39 years and 16 to 38 years, respectively. The vocal symptoms associated with arytenoid asymmetry in the present study were occasional dysphonia (4%), pharyngeal dryness (2%) and vocal fatigue (2%). Hamdan et al. [8] also reported vocal symptoms such as hoarseness (19%), breathlessness (2.7%), vocal fatigue (22.7%) and inability to project the voice (0.9%) and they also reported the absence of any correlation between these various vocal symptoms and arytenoid asymmetry. Most of the studies published to date have shown that arytenoid asymmetry is predominantly observed on the right side. In the present series, arytenoid asymmetry was predominantly observed on the right side (64.5%) compared to the left side (35.5%). These results are similar to those reported by Hamdan et al. [8] and Husseini et al. [9], who also reported a marked predominance of right arytenoid asymmetry in their studies (74.2 and 70%). This right-sided predominance can be explained by the asymmetrical position of the cricoarytenoid joint and a long thyroid lamina tilted towards the left. A compensatory mechanism may also be involved to maintain symmetry of the vocal folds during phonation, as the arytenoid cartilages slide from a posterosuperior midline position to an anteroinferior lateral position and vice versa during adduction and abduction movements. Because vocal fold vibrations require adequate glottic closure in singers, alignment of the vocal folds in the vertical and horizontal planes is therefore crucial. If arytenoid asymmetry in adduction is a compensatory phenomenon due to anatomical asymmetry, it would therefore be reasonable to suppose that singers who are able to compensate by more accurately aligning their vocal folds would have a better quality voice than those who compensate less effectively. Among the various types of arytenoid asymmetry observed in this study, cuneiform asymmetry was predominant (37.5%), followed by aryepiglottic angle asymmetry (33.1%) and corniculate asymmetry (29.4%). These results corroborate those reported by Hamdan et al. [8] and Husseini et al. [9]. Bonilha et al. [10] also reported similar results in their study in normal subjects.
4. Discussion Phonation is a complex process that requires coordination and stability between various body systems. Phonation consists of adduction of the vocal folds during voice production. Adequate adjustment of the horizontal and vertical positions of the vocal folds is important, as poor alignment or incomplete closure of the vocal folds can be responsible for voice disorders. Laryngeal asymmetry is not rare. Like other paired organs of the body subject to asymmetry, laryngeal structures can present
5. Conclusion Arytenoid asymmetry is frequent in singers, as about one in two singers may present arytenoid asymmetry in adduction. However, the presence of arytenoid asymmetry does not appear to be correlated with any vocal symptoms.
Please cite this article in press as: Clarós P, et al. Arytenoid asymmetry in opera singers. European Annals of Otorhinolaryngology, Head and Neck diseases (2018), https://doi.org/10.1016/j.anorl.2018.08.014
G Model ANORL-812; No. of Pages 4
ARTICLE IN PRESS P. Clarós et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2018) xxx–xxx
4
Disclosure of interest The authors declare that they have no competing interest. References [1] Kasperbauer JL. A biomechanical study of the human cricoarytenoid joint. Laryngoscope 1998;108(11 Pt 1):1704–11. [2] Friedrich G, Kainz J, Schneider GH, Anderhuber F. Computed tomography of the larynx in the diagnosis of dysphonia. Folia Phoniatr (Basel) 1989;41(6):283–91. [3] Friedrich G, Kainz J. Morphometry of the larynx in horizontal sections. Normal data for the quantitative evaluation of current imaging technics. Laryngol Rhinol Otol (Stuttg) 1988;67(6):269–74. [4] Friedrich G, Kainz J, Freidl W. Morphological discrepancies and their clinical significance. Record of the German Gellshaft for oto-rhino-laryngology, head and neck surgery. Otorhinolaryngology 1989;(Suppl.):19–20.
[5] Hirano M, Kurita S, Yukisane K, Hibi S. Asymmetry of the laryngeal framework: a morphologic study of cadaver larynges. Ann Otol Rhinol Laryngol 1989;98:135–40. [6] Lindestad PA, Hertegård S, Björck G. Laryngeal adduction asymmetries in normal speaking subjects. Logoped Phoniatr Vocol 2004;29:128–34. [7] Lacina O. Die adduktionelle Asymmetrie des Kehlkopfes bei den Sängern (Asymmetria arytenoidea cruciata cantatorum). Folia Phoniatr 1970;22:100–6. [8] Hamdan AL, Husseini ST, Halawi A, Sibai A. Arytenoid asymmetry in relation to vocal symptoms in singers. J Voice 2011;25(2):241–4. [9] Husseini ST, Ashkar J, Halawi A, Sibai A, Hamdan AL. Arytenoid asymmetry in relation to posture, neck tension and glottal attack in singers. Folia Phoniatr Logop 2011;63(5):264–8. [10] Bonilha HS, O’Shields M, Gerlach TT, Deliyski DD. Arytenoid adduction asymmetries in persons with and without voice disorders. Logoped Phoniatr Vocol 2009;34(3):128–34.
Please cite this article in press as: Clarós P, et al. Arytenoid asymmetry in opera singers. European Annals of Otorhinolaryngology, Head and Neck diseases (2018), https://doi.org/10.1016/j.anorl.2018.08.014
ARTICLE IN PRESS European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2018) xxx–xxx
Available online at
ScienceDirect www.sciencedirect.com
Original article
Arytenoid asymmetry in opera singers P. Clarós ∗ , A. Clarós-Pujol , A. Clarós Oto-Rhino-Laryngologie, Clínica Clarós, c/. Los Vergós, 31, 08017 Barcelona, Spain
a r t i c l e
i n f o
Keywords: Arytenoid asymmetry Vocal symptoms Opera singers
a b s t r a c t Introduction: Otolaryngologists commonly observe asymmetrical movements of the arytenoid cartilages, but few authors have described the clinical implications of this asymmetry, especially in singers. Objectives: The aim of this study was to determine the epidemiological and clinical characteristics of arytenoid asymmetry in adduction in a group of healthy opera singers and to evaluate the impact of this asymmetry on the voice. Patients and methods: The medical charts and laryngeal video recordings of 245 healthy opera singers were retrospectively reviewed. Arytenoid asymmetry was defined in relation to the position of the corniculate cartilages, cuneiform cartilages and aryepiglottic angle. Results: The subjects had a mean age of 38.54 years (range: 18 to 85 years) and presented a male-tofemale sex ratio of 1.02. About 5% of subjects had a history of smoking. The most common vocal symptoms were occasional dysphonia (4%), followed by vocal fatigue (2%) and pharyngeal dryness (2%). Arytenoid asymmetry was slightly more common in males (50.6%) and predominantly affected the right side (64.5%). The most common form of asymmetry was cuneiform asymmetry (37.5%), followed by aryepiglottic angle asymmetry in 33.1% of cases and corniculate asymmetry in 29.4% of cases. Mild asymmetry was observed in the majority of cases. No correlation was observed between arytenoid asymmetry and vocal symptoms. Conclusion: Almost one out of two singers was likely to present arytenoid asymmetry in adduction. The presence of this asymmetry does not appear to be correlated with any vocal symptoms. © 2018 Elsevier Masson SAS. All rights reserved.
1. Introduction The larynx plays an essential role in breathing, phonation and deglutition. It is composed of several cartilages connected by joints, ligaments, membranes and muscles. The key element for maintenance of laryngeal integrity and function is an intact and mobile cricoarytenoid joint. Arytenoid adduction is characterized by anteroposterior tilting on the long axis of the arytenoid cartilages, lateral sliding and a small degree of rotation [1]. It is often attributed to asymmetry of the laryngeal cartilages, as already reported by several authors [2–5]. In their radiological study of patients presenting with voice disorders, Friedrich et al. [2–4] showed that asymmetry was common in dysphonic subjects and was related to vocal symptoms. Hirano et al. [5] reported similar results by showing that the anteroposterior dimensions of the thyroid cartilage were longer on the left side than on the right side. The prevalence of arytenoid asymmetry varies as a function of the type of asymmetry and the patient’s age and sex. In their study of 109 subjects not presenting any voice disorders, Lindestad et al.
[6] reported a 70% incidence of arytenoid asymmetry. The most frequent type of asymmetry (66% of patients), accounting for 92% of all cases of asymmetry observed, consisted of lateral differences in the anteroposterior position of the corniculate or cuneiform cartilages [6]. These authors also reported that asymmetry was more frequent in older people and singers. These results corroborate those reported by Lacina [7] in a cohort of Milanese opera singers. Using indirect mirror laryngoscopy, Lacina [7] reported a high incidence of arytenoid asymmetry in singers compared to non-singers and attributed these results to the fact that singers had to more accurately compensate for anatomical variants of laryngeal cartilages in order to more effectively align their vocal folds when singing. Very few data on arytenoid asymmetry in adduction are available at the present time. The objective of this study was to determine the epidemiological and clinical characteristics of arytenoid asymmetry in a series of opera singers and to look for a possible correlation between arytenoid asymmetry and vocal symptoms. 2. Materials and methods
∗ Corresponding author. E-mail address: [email protected] (P. Clarós).
We conducted a retrospective, descriptive study on a series of 250 opera singers (professional singers, amateur singers and
https://doi.org/10.1016/j.anorl.2018.08.014 1879-7296/© 2018 Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Clarós P, et al. Arytenoid asymmetry in opera singers. European Annals of Otorhinolaryngology, Head and Neck diseases (2018), https://doi.org/10.1016/j.anorl.2018.08.014
G Model ANORL-812; No. of Pages 4 2
ARTICLE IN PRESS P. Clarós et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2018) xxx–xxx
Fig. 1. Normal larynx.
Fig. 2. Various types of asymmetry: a: right corniculate asymmetry due to overlap; b: right cuneiform asymmetry in an anterior position; c: aryepiglottic angle asymmetry; d: left cuneiform asymetry.
singing students) attending our otorhinolaryngology clinic in Barcelona, Spain. Inclusion criteria were all patients over the age of 18 years presenting arytenoid asymmetry. The patients’ medical charts and video recordings were examined. All patients with a history of surgery or laryngeal disease, such as nodules, polyps, cysts and other tumours, were excluded from this study. All patients were examined by an experienced otorhinolaryn® gologist using a Karl Storz 90◦ rigid endoscope connected to a camera. Videos were recorded during phonation and the various types of arytenoid asymmetry in adduction observed were listed. Arytenoid asymmetry was classified into 3 types according to the position of the corniculate and cuneiform cartilages, and the aryepiglottic angle (angle between the aryepiglottic cartilage and the epiglottis) compared to a normal larynx (Figs. 1 and 2).
Corniculate asymmetry was defined by the presence of prominent corniculate cartilages or in an anterior position compared to the contralateral side. Cuneiform asymmetry was defined by the anterior position of the cuneiform cartilages compared to the contralateral side. Aryepiglottic angle asymmetry was noted when a more acute angle was observed on one side compared to the opposite side. The various degrees of asymmetry were classified into three groups: mild, moderate and severe. The side of asymmetry was also specified (right or left). The following variables were studied: age, sex, type, laterality and degree of arytenoid asymmetry observed in each subject. A history of smoking and vocal symptoms, such as dysphonia, cough, hoarseness or vocal fatigue, were also investigated.
Please cite this article in press as: Clarós P, et al. Arytenoid asymmetry in opera singers. European Annals of Otorhinolaryngology, Head and Neck diseases (2018), https://doi.org/10.1016/j.anorl.2018.08.014
G Model
ARTICLE IN PRESS
ANORL-812; No. of Pages 4
P. Clarós et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2018) xxx–xxx Table 1 Epidemiological characteristics of the singers. Number of singers Sex ratio (male/female) Age Mean age Range Smokers Associated symptoms Occasional dysphonia Pharyngeal dryness Vocal fatigue
245 1.02 38.54 years 18–85 years 5% 4% 2% 2%
Table 2 Prevalence of arytenoid asymmetry (%). Arytenoid asymmetry Right asymmetry Left asymmetry Women Men
64.5 35.5 49.4 50.6
Table 3 Types of arytenoid asymmetry (%). Cuneiform asymmetry Mild Moderate Severe Corniculate asymmetry Mild Moderate Severe Aryepiglottic angle asymmetry Mild Moderate Severe
37.5 67.4 25 7.6 29.4 61.1 34.7 4.2 33.1 38.3 55.5 6.2
3. Results 3.1. Epidemiological data A total of 245 singers with a mean age of 38.54 years (range: 18 to 85 years) and an M/F sex ratio of 1.02 (124 men and 121 women) were included in this study. About 5% of subjects reported a history of smoking. The symptoms associated with arytenoid asymmetry were occasional dysphonia (4%), pharyngeal dryness (2%) and vocal fatigue (2%) (Table 1). 3.2. Arytenoid asymmetry In this study, arytenoid asymmetry was more frequent on the right side (64.5%) than on the left side (35.5%) and was slightly more frequent in men (50.6%) than in women (49.4%) (Table 2). The type of asymmetry most commonly observed was cuneiform asymmetry in 37.5% of cases, followed by aryepiglottic angle asymmetry in 33.1% of cases and finally corniculate asymmetry in 29.4% of cases. Asymmetry was considered to be mild in the majority of cases (Table 3).
3
different positions, dimensions and shapes. However, arytenoid asymmetry appears to be more frequent in abduction than in phonation. When arytenoid asymmetry is observed in adduction, otorhinolaryngologists are often unable to distinguish between normal and pathological appearances. Despite the importance of the cricoarytenoid joint, very few studies have evaluated the prevalence of arytenoid asymmetry in adduction, its clinical impact on phonation and its association with vocal symptoms, especially in singers [5–7]. A slight male predominance of arytenoid asymmetry (M/F sex ratio: 1.02) was observed in this study. Hirano et al. [5] also reported no particular anatomical difference between the two sexes in their series. On the other hand, Hamdan et al. [8] and Husseini et al. [9] reported a marked male predominance of arytenoid asymmetry in their respective series of singers. Anatomical studies have shown a higher prevalence of laryngeal asymmetry in older people [5]. The mean age of the patients in this series was 38.54 years (range: 18 to 85 years), while Hamdan et al. [8] and Husseini et al. [9] reported a mean age of 23.4 years and 24 years in their respective series. This difference can be explained by the fact that their subjects were younger with an age range of 15 to 39 years and 16 to 38 years, respectively. The vocal symptoms associated with arytenoid asymmetry in the present study were occasional dysphonia (4%), pharyngeal dryness (2%) and vocal fatigue (2%). Hamdan et al. [8] also reported vocal symptoms such as hoarseness (19%), breathlessness (2.7%), vocal fatigue (22.7%) and inability to project the voice (0.9%) and they also reported the absence of any correlation between these various vocal symptoms and arytenoid asymmetry. Most of the studies published to date have shown that arytenoid asymmetry is predominantly observed on the right side. In the present series, arytenoid asymmetry was predominantly observed on the right side (64.5%) compared to the left side (35.5%). These results are similar to those reported by Hamdan et al. [8] and Husseini et al. [9], who also reported a marked predominance of right arytenoid asymmetry in their studies (74.2 and 70%). This right-sided predominance can be explained by the asymmetrical position of the cricoarytenoid joint and a long thyroid lamina tilted towards the left. A compensatory mechanism may also be involved to maintain symmetry of the vocal folds during phonation, as the arytenoid cartilages slide from a posterosuperior midline position to an anteroinferior lateral position and vice versa during adduction and abduction movements. Because vocal fold vibrations require adequate glottic closure in singers, alignment of the vocal folds in the vertical and horizontal planes is therefore crucial. If arytenoid asymmetry in adduction is a compensatory phenomenon due to anatomical asymmetry, it would therefore be reasonable to suppose that singers who are able to compensate by more accurately aligning their vocal folds would have a better quality voice than those who compensate less effectively. Among the various types of arytenoid asymmetry observed in this study, cuneiform asymmetry was predominant (37.5%), followed by aryepiglottic angle asymmetry (33.1%) and corniculate asymmetry (29.4%). These results corroborate those reported by Hamdan et al. [8] and Husseini et al. [9]. Bonilha et al. [10] also reported similar results in their study in normal subjects.
4. Discussion Phonation is a complex process that requires coordination and stability between various body systems. Phonation consists of adduction of the vocal folds during voice production. Adequate adjustment of the horizontal and vertical positions of the vocal folds is important, as poor alignment or incomplete closure of the vocal folds can be responsible for voice disorders. Laryngeal asymmetry is not rare. Like other paired organs of the body subject to asymmetry, laryngeal structures can present
5. Conclusion Arytenoid asymmetry is frequent in singers, as about one in two singers may present arytenoid asymmetry in adduction. However, the presence of arytenoid asymmetry does not appear to be correlated with any vocal symptoms.
Please cite this article in press as: Clarós P, et al. Arytenoid asymmetry in opera singers. European Annals of Otorhinolaryngology, Head and Neck diseases (2018), https://doi.org/10.1016/j.anorl.2018.08.014
G Model ANORL-812; No. of Pages 4
ARTICLE IN PRESS P. Clarós et al. / European Annals of Otorhinolaryngology, Head and Neck diseases xxx (2018) xxx–xxx
4
Disclosure of interest The authors declare that they have no competing interest. References [1] Kasperbauer JL. A biomechanical study of the human cricoarytenoid joint. Laryngoscope 1998;108(11 Pt 1):1704–11. [2] Friedrich G, Kainz J, Schneider GH, Anderhuber F. Computed tomography of the larynx in the diagnosis of dysphonia. Folia Phoniatr (Basel) 1989;41(6):283–91. [3] Friedrich G, Kainz J. Morphometry of the larynx in horizontal sections. Normal data for the quantitative evaluation of current imaging technics. Laryngol Rhinol Otol (Stuttg) 1988;67(6):269–74. [4] Friedrich G, Kainz J, Freidl W. Morphological discrepancies and their clinical significance. Record of the German Gellshaft for oto-rhino-laryngology, head and neck surgery. Otorhinolaryngology 1989;(Suppl.):19–20.
[5] Hirano M, Kurita S, Yukisane K, Hibi S. Asymmetry of the laryngeal framework: a morphologic study of cadaver larynges. Ann Otol Rhinol Laryngol 1989;98:135–40. [6] Lindestad PA, Hertegård S, Björck G. Laryngeal adduction asymmetries in normal speaking subjects. Logoped Phoniatr Vocol 2004;29:128–34. [7] Lacina O. Die adduktionelle Asymmetrie des Kehlkopfes bei den Sängern (Asymmetria arytenoidea cruciata cantatorum). Folia Phoniatr 1970;22:100–6. [8] Hamdan AL, Husseini ST, Halawi A, Sibai A. Arytenoid asymmetry in relation to vocal symptoms in singers. J Voice 2011;25(2):241–4. [9] Husseini ST, Ashkar J, Halawi A, Sibai A, Hamdan AL. Arytenoid asymmetry in relation to posture, neck tension and glottal attack in singers. Folia Phoniatr Logop 2011;63(5):264–8. [10] Bonilha HS, O’Shields M, Gerlach TT, Deliyski DD. Arytenoid adduction asymmetries in persons with and without voice disorders. Logoped Phoniatr Vocol 2009;34(3):128–34.
Please cite this article in press as: Clarós P, et al. Arytenoid asymmetry in opera singers. European Annals of Otorhinolaryngology, Head and Neck diseases (2018), https://doi.org/10.1016/j.anorl.2018.08.014