Figure 1.

The learning curve for the transoral endoscopic thyroidectomy vestibular approach (TOETVA). The simple moving average curve is depicted in red, which was used to define the proficiency case, as seen by the vertical line at case 11. The slope of the skill acquisition period (cases 1-11) is depicted by the dashed black line, while the slope of the proficiency period (cases 12-30) is denoted by the solid black line. These slopes are significantly different from each other (P < .001).