Quantitative Videostroboscopic Measurement of Glottal Gap and Vocal Function: An Analysis of Thyroplasty Type I

Abstract

The goal of surgical medialization of the vocal fold is to attain complete glottic closure. The purpose of this study is to quantify the glottal gap and to examine the relationship between glottal gap and vocal function perioperatively in thyroplasty type I. Glottal gap area was measured in 20 patients at the point of maximum closure of vocal fold vibration in digitized laryngeal stroboscopic images and was normalized by the square of vocal fold length. Glottal gap area thus measured was correlated with results obtained from well-accepted acoustic, aerodynamic, and perceptual measures of vocal function. The glottal gap was significantly reduced after thyroplasty type I. In patients with small preoperative glottal gaps, the amplitude of vocal fold vibration was significantly improved. This study verifies that quantitative videostroboscopic measurement of the glottal gap is a useful means of objective evaluation of glottic incompetence and of the results of thyroplasty type I.

Quantitative microlaryngoscopic measurements of vocal fold polyps, glottal gap and their relation to vocal function

“…Authors found a positive correlation between glottic area and breathy voice in unilateral vocal fold paralysis and confirmed that even only measurement of relative glottic space provides a direct assessment of glottic incompetence and objectively demonstrates the effect of surgical medialization (4,5).…”

“…Measurements of actual size of pathological lesions and anatomical structures are of great clinical importance in practical medicine, as it provides objective additional information, which is crucially important for diagnostics, planning of treatment and assessment of outcomes of therapeutical or surgical management (4)(5)(6)14). On the other hand, in laryngology, these measurements are of great interest for scientific purposes revealing the impact of actual size of vocal fold mass lesions in pathogenesis of voice disorders and would be helpful elaborating automatic methods of image and voice analysis (9,15).…”

“…On the other hand, in laryngology, these measurements are of great interest for scientific purposes revealing the impact of actual size of vocal fold mass lesions in pathogenesis of voice disorders and would be helpful elaborating automatic methods of image and voice analysis (9,15). Several methods of measurements of video laryngostroboscopic images and glottic gap providing with the relative or absolute measures and their clinical implications have been described in the literature (1,2,5). However, these models of glottic gap measurement seem to be impractical in cases when part of glottis is occupied by some pathological growth.…”

“…Some studies have attempted to measure the glottic space from video laryngostroboscopic images objectively and determine the relationship between the relative glottic space and the degree of breathiness in dysphonic patients (4), to quantify criteria for prediction and evaluation of outcome of surgical treatment of unilateral laryngeal paralysis (5,6). Authors found a positive correlation between glottic area and breathy voice in unilateral vocal fold paralysis and confirmed that even only measurement of relative glottic space provides a direct assessment of glottic incompetence and objectively demonstrates the effect of surgical medialization (4,5).…”

Diagnostic Challenge of Sulcus Vocalis Made Easier

“…Prior studies have mentioned the use of digitized stroboscopes for determining the phonatory gap, which may not be widely available. 13,14 As per our study, the gap can be measured with the help of a printout of a recorded white light image and a ruler. On analysis, if the phonatory gap is asymmetric, then the diagnosis of sulcus vocalis should be suspected, which should then be confirmed on stroboscopy.…”