The vestibular ligament (vestibular chorda), or mucotracheal fold (glosso pharyngeus), is a chord (a long and thin strip) of the mucous membrane that attaches the soft palate to the lower border of the posterior wall of the pharynx in front. It is also called "limbicoglossum" (from the Latin lingua - tongue and pharynx - pharynx) and is part of the structure of the lingual tubercle, which resembles a mussel. Despite its importance, this is an incredibly rare phenomenon that nature has endowed humans with - only 2% of people have a vestibular ligament. This is due to the peculiarity of the development of human organs in the womb. Surprisingly, this fold is present only in men.
The vestibule ligament prevents the soft palate from drooping to the side, which maintains the integrity of the vocal cords and thereby protects them from injury and strain during speech. In most people, the soft palate hangs freely over the vocal folds, creating a vocal resonator that is responsible for the sonority and spectrum of the voice. With such an anatomy, a person has to make great efforts to speak correctly and clearly, so his speech becomes tense, and sometimes hoarseness and wheezing are heard.
The attachment of the soft palate to the ligament of the vestibule ensures the functioning of the ligaments, making the movements of the tongue and jaw more smooth and coordinated. In addition, the fold has a protective function, protecting the mucous membrane of the throat, vocal cords and teeth. This chordal passage ensures free movement of the tongue along the esophagus and makes swallowing painless, since the mucous membrane is not pinched and remains mobile.