Endoscopic and Computed Tomography Evaluation of Posterior Glottic Closure During Phonation.

OBJECTIVES/HYPOTHESIS: The anatomy of the posterior glottis, specifically the states of the posterior glottis during phonation, has not been thoroughly explored in laryngology. Conventional wisdom about the posterior glottis indicates that it tends to be completely closed in men but may be open in women. Furthermore, professional singers are expected to have a completely closed posterior glottis. The aim of this study was to investigate whether these generalizations are true by comparing rigid videolaryngostroboscopy results with high-resolution computed tomography (HRCT) and three-dimensional (3D) reconstruction findings. STUDY DESIGN: Prospective study. METHODS: Of the 90 volunteers (58 women, 32 men) examined, 48 were female professional singers, 10 were female nonsingers, 22 were male professional singers, and 10 were male nonsingers. Rigid videolaryngostroboscopy as well as HRCT scans were performed during singing at the average singing fundamental frequency. HRCT images of the larynx and air-column were 3D visualized using the software MIMICS®. The states of the posterior glottis were assessed in both examinations and compared among participants. RESULTS: The sensitivity of endoscopy was 67.5%. Complete closure of the posterior glottis was observed in 62.5% men and 52% women (P = .33). Complete closure of the posterior glottis was observed in 35% nonsingers and 61% professional singers (P = .036). CONCLUSIONS: The closure of the posterior glottis seen on videolaryngostroboscopy does not always correlate with actual closure. There seems to be no link between sex and complete closure of the glottis. However, there is strong evidence that posterior glottis closure can be influenced, to some degree, by vocal training. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:124-129, 2022.

Surgical Impact of the Montgomery Implant System on Arytenoid Cartilage and the Paralyzed Vocal Fold.

OBJECTIVES/HYPOTHESIS: Medialization thyroplasty (MT) has become a prominent method for treating glottal insufficiency. This study aimed to visualize the biomechanical influence of a medialization implant on arytenoid cartilage, particularly on the length and level of paralyzation in the vocal fold, in patients with unilateral vocal fold paralysis. STUDY DESIGN: Prospective study. METHODS: We recruited 15 patients (10 men, 5 women) with unilateral vocal fold paralysis that underwent MT with a Montgomery® thyroplasty implant. We performed high-resolution computed tomography of the arytenoid cartilage before and after MT and analyzed the three-dimensional images. To visualize the movement of the arytenoid and to measure the lengthening of the vocal fold, we superimposed pre- and postoperative 3D images with MIMICS software. RESULTS: On the affected side, the implant pushed the arytenoid backwards. In addition, the vocal process of the arytenoid was inwardly rotated. These movements resulted in an elongated, augmented vocal fold on the affected side. CONCLUSION: MT led to an elongated, medialized vocal fold on the treated side. After the intervention, the vocal folds on both sides were the same length in the phonatory position.

The Cricothyroid Joint: A Practical Guide for Distinguishing Between Different Joint Types.

OBJECTIVE: Type A cricothyroid joint (CTJ) leads to a higher elongation of the vocal folds than Type B/C CTJ. Therefore, the determination for the CTJ type is important whether to perform a cricoid-thyroid approximation for a pitch elevation in transwomen with gender dysphoria. This study aimed to develop a tool for clinicians and radiologists for distinguishing between Type A (cricoid cartilage protuberance) and Type B/C (flat surface with/without cartilage of the cricoid) CTJs on high-resolution computed tomography (HRCT). STUDY DESIGN: This was a prospective study. METHODS: Analysis of 60 male HRCTs and 60 female HRCTs of the larynx/CTJs. Three-dimensional reconstruction of the laryngeal cartilages, based on visualization of the CTJ in HRCT scans. The intercartilaginous distances (nearest distance between the inner side of the Thyroid and outer side of the cricoid of the CTJ) were measured to compare different types of CTJs. RESULTS: In all HRCT scans, three-dimensional reconstructions of the CTJ were feasible. All Type A CTJs showed the typical cricoid cartilage protuberance (like a volcano) in biplanar images and three-dimensional reconstructions. All Type B/C CTJs showed a flat cricoid joint cartilage in biplanar images and three-dimensional reconstructions. The type distribution was Type A: 61% in male and female larynges; Type B/C: 39% in male and female larynges. The intercartilaginous distances were Type A: 0.71 mm [0.42-0.98] in male larynges and 0.75 mm [0.44-1.40] in female larynges; Type B/C: 1.13 mm [0.36-1.24] in male larynges and 1.32 mm [0.76-2.47] in female larynges. CONCLUSIONS: In HRCT scans, the Type A CTJ showed an intercartilaginous space less than 1 mm. In contrast, the Type B/C CTJ showed an intercartilaginous distance exceeded 1 mm.

Medical lectures upgraded: 11 hacks from comedy.

We believe that medical lectures can be improved by considering techniques from comedy. Foremost, lecturers should educate their audiences. This works well, if lecturers have fun and entertain. In preparing the presentation, they should develop a storyline, try to surprise their audience, prepare to employ unexpected objects and carry out several test runs. During the presentation, lecturers should dare to use self-irony, appeal to students' emotions, be factual and precise, serve the audience, keep it short and provide memorable opening and closing statements. Medical lectures should be both informative and entertaining.

How Age and Frequency Impact the Thyroid Cartilages of Professional Singers.

OBJECTIVES/HYPOTHESIS: Young professional singers can easily reach very high pitches. In contrast, older singers often complain that they have to exert substantially more laryngopharyngeal force to reach the same high pitch compared with their earlier years. Various factors such as the property changes of the mucosa and ossification that impact the singing apparatus were suggested as explanations in the literature. The aim of this study was to analyze thyroid deformation-and thereby stiffness indirectly-during singing as a potential reason for this phenomenon. STUDY DESIGN: Prospective study. METHODS/DESIGN: We examined 44 female professional singers. High-resolution computed tomography scans were performed during singing at the fundamental mean speaking frequency and the first and second octaves above it. Digital Imaging and Communications in Medicine scan data were rendered and visualized 3-dimensionally using MIMICS software. By superimposition of the different 3-dimensional images, different positions of the thyroid were visualized. The distance from the posterior border of the thyroid was measured in all the examinations. RESULTS: All laryngeal cartilages could be three-dimensionally visualized. The magnitude of the thyroidal deformation significantly depends on pitch and significantly correlates with age (r2 = 0.7, P < 0.001). CONCLUSIONS: The thyroid cartilage is flexible and its formability is especially important during singing. At higher pitches, the cartilage was more deformed. The larynx in older singers showed less thyroid cartilage deformation.

Cricothyroid joint type as predictor for vocal fold elongation in professional singers.

OBJECTIVE: Vocal fold (VF) elongation vocal folds depends on two factors: the activity of the laryngeal muscles and the cricothyroid joint (CTJ). The aim of the study was to show the influence of the CTJ on VF elongation while singing a sustained vowel at different pitches. STUDY DESIGN: Prospective study. METHODS: Forty-nine female professional singers (25 sopranos, 24 altos) were recruited. Three-dimensional images of the larynx derived from high-resolution computed tomography scanning were obtained at the mean speaking fundamental frequency (F0) and one (F1) and two octaves (F2) above this pitch. RESULTS: From F0 to F1, all three CTJ types showed equal elongation of the VF (type A: 14%, type B/C: 13%). From F1 to F2, VF elongation was 8% in singers with type A and 4% in those with type B/C (P < 0.0001). CONCLUSION: The stability of the CTJ directly influences VF during singing. This is the first study to show this relationship in vivo. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:1176-1181, 2018.

3D analysis of the movements of the laryngeal cartilages during singing.

OBJECTIVE: The vocal range of untrained singers rarely exceeds one and a half octaves, but professional singers have a range of at least two and a half octaves. The aim of this study was to better understand the muscle and cartilage movements responsible for the control of vocal pitch in singing. STUDY DESIGN: Prospective study. METHODS: We recruited 49 female professional singers (25 sopranos and 24 altos) and analyzed laryngeal three-dimensional images derived from high-resolution computed tomography scans obtained at the mean speaking fundamental frequency (F0) and at one (F1) and two octaves (F2) above this pitch. RESULTS: From F0 to F1, the only observable movement was a backward cricoid tilting caused by the cricothyroid muscles (CTMs), leading to vocal fold stretching. Above F1, a medial rotation and inward rocking of the arytenoid cartilages was observed, caused by the lateral cricothyroid muscles (LCAMs) and leading to inferior displacement of the vocal process of the arytenoid cartilage, and thus to further vocal fold stretching. CONCLUSION: Trained singers achieve the first octave of pitch elevation by simple cricothyroid approximation. Further pitch elevation necessitates a complex movement of the arytenoids, first by CTM contraction and second by LCAM contraction. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:1639-1643, 2017.

Three-dimensional Imaging of High-resolution Computer Tomography of Singers' Larynges-A Pilot Study.

OBJECTIVES/HYPOTHESIS: Biplanar imaging technique is not sufficient for an exact visualization and evaluation of the laryngeal biomechanics during speaking or singing. The aim of this pilot study was to test a 3D-visualization software MIMICS (Materialize Interactive Medical Image Control System, Materialize, Leuven, Belgium) for visualizing laryngeal cartilages and resonance space of living humans during singing based on high-resolution computed tomography (HRCT) and analyzing the biomechanics thereof. STUDY DESIGN: This is a prospective pilot study. METHODS: A total of 10 professional female singers (five sopranos and five altos) was scanned with HRCT in three singing positions fundamental frequency (ƒo), first octave (ƒo+1 8va) and second octave (ƒo+2 8va). RESULTS: All relevant laryngeal structures and resonance space could be 3D visualized. Superimposing the different HRCT scans showed an inward rotation and rocking of the arytenoid cartilages from ƒo+1 8va to ƒo+2 8va and a backward tilting of the cricoid cartilage from ƒo+1 8va to ƒo+2 8va. Moreover, we could demonstrate a vocal fold elongation of 13% from ƒo to ƒo+1 8va and an additional elongation from ƒo+1 8va to ƒo+2 8va of 10% in type A cricothyroid joints (CTJ) A and 4% in CTJ's type B/C. There were no significant differences between sopranos and altos in all parameters (length of the glottis, subglottic diameter, distance between anterior commissure and cervical spine, and CTJ distribution). CONCLUSIONS: This noninvasive 3D-visualization technique with MIMICS allows the anatomical structures and landmarks of the larynx to be analyzed. We believe that this pilot study will serve as a basis for further biomechanical studies on speakers' and singers' larynges.