National Center for Voice and Speech, University of Utah, Salt Lake City, Utah, U.S.A.
Department of Communication Sciences and Disorders, University of Iowa, Iowa City, Iowa, U.S.A.
Laryngoscope. 2020 Sep;130(9):2192-2198. doi: 10.1002/lary.28365. Epub 2019 Oct 23.
Most type 1 thyroplasty implants and some common injectable materials are mechanically stiff. Placing them close to the supple vocal fold mucosa can potentially dampen vibration and adversely impact phonation, yet this effect has not been systematically investigated. This study aims to examine the effect of implant depth on vocal fold vibration and vocal output.
Computational simulation.
Voice production was simulated with a fiber-gel finite element computational model that incorporates a three-layer vocal fold composition (superficial lamina propria, vocal ligament, thyroarytenoid muscle). Implants of various depths were simulated, with a "deeper" or more medial implant positioned closer to the vocal fold mucosa and replacing more muscle elements. Trajectories of surface and within-tissue nodal points during vibration were produced. Outcome measures were the trajectory radii, fundamental frequency (F ), sound pressure level (SPL), and smoothed cepstral peak prominence (CPPS) as a function of implant depth.
Amplitude of vibration at the vocal fold medial surface was reduced by an implant depth of as little as 14% of the total transverse vocal fold depth. Increase in F and decrease in CPPS were noted beyond 30% to 40% implant depth, and SPL decreased beyond 40% to 60% implant depth.
Commonly used implants can dampen vibration "from a distance," ie, even without being immediately adjacent to vocal fold mucosa. Since implants are typically placed at depths examined in this study, stiff implants likely have a negative vocal impact in a subset of patients. Softer materials may be preferable, especially in bilateral medialization procedures.
N/A Laryngoscope, 130:2192-2198, 2020.
大多数 1 型甲状软骨成形术植入物和一些常见的注射材料在机械上都很僵硬。将它们放置在靠近柔软的声带黏膜附近可能会抑制振动，并对发声产生不利影响，但尚未系统地研究这种影响。本研究旨在检查植入物深度对声带振动和发声输出的影响。
计算模拟。
使用纤维-凝胶有限元计算模型模拟发声，该模型包含三层声带组成部分（浅层固有层、声带韧带、甲状杓肌）。模拟了各种深度的植入物，“更深”或更内侧的植入物更靠近声带黏膜，并取代更多的肌肉元素。产生了振动过程中表面和组织内节点的轨迹。测量指标为轨迹半径、基频（F ）、声压级（SPL）和作为植入物深度函数的平滑倒谱峰值突出度（CPPS）。
植入物深度仅为总横向声带深度的 14%，就会降低声带内侧表面的振动幅度。超过 30%至 40%的植入物深度时，F 增加，CPPS 降低，超过 40%至 60%的植入物深度时，SPL 降低。
常用的植入物即使不直接与声带黏膜相邻，也可以“远距离”阻尼振动。由于植入物通常放置在本研究中检查的深度，因此在一部分患者中，僵硬的植入物可能对发声产生负面影响。较软的材料可能更可取，特别是在双侧内侧化手术中。
无喉科学，130:2192-2198，2020。
