The idea of being born with a literal extra vocal cord, a third fully functioning structure, is not typically observed in human anatomy. However, this concept relates to rare, complex birth defects known as congenital laryngeal anomalies, which result in extra or duplicated tissue within the voice box. These conditions arise from developmental errors during gestation, creating structures that obstruct the airway. Instead of a perfect duplicate, these anomalies present as supernumerary folds, webs, or cysts that interfere with normal breathing and voice production.
Understanding Normal Vocal Fold Anatomy
The structures responsible for voice and breathing are correctly termed vocal folds, not cords, and they are located within the larynx. The normal larynx contains a single, symmetrical pair of vocal folds, one on the left and one on the right. These folds are multilayered, composed of a vocal ligament, the vocalis muscle, and a covering of mucous membrane. Their primary function is threefold: to protect the airway during swallowing, to control the flow of air into the lungs during breathing, and to produce sound.
Sound is generated when air expelled from the lungs passes between the nearly closed folds, causing the mucosal covering to vibrate rapidly. This vibration, known as the mucosal wave, creates the voice. The symmetrical and pliable nature of the two folds is necessary for a clear, controlled voice and unobstructed breathing. When the folds are open, they form a “V” shape, creating the glottic opening that allows air to pass freely into the trachea.
Congenital Laryngeal Anomalies
The conditions that can present as “extra” vocal cord material are highly uncommon and originate from errors in embryonic development, specifically the formation of the laryngotracheal tube. During the third month of gestation, the tube separating the airway from the esophagus should fully recanalize, or reopen, a process that occasionally fails. Incomplete recanalization can result in a laryngeal web, which is a sheet of tissue connecting the two vocal folds, most often at the front of the larynx.
A more direct form of duplication is known as supernumerary vocal folds or congenital duplication of the larynx. These anomalies can manifest as vestigial secondary folds located either above or below the true vocal folds. In some instances, the entire larynx, including the epiglottis and vocal folds, has been partially duplicated, forming a mirror-image accessory structure. These duplicated structures are often non-functional but can cause significant obstruction. Other space-occupying lesions, like congenital laryngeal cysts, can also appear as extra tissue protruding into the airway, interfering with fold movement and function.
Recognizing Symptoms of Laryngeal Duplication
When an anomaly like laryngeal duplication or a web is present, the primary symptoms reflect the obstruction of the airway or the alteration of the voice mechanism. The most common and noticeable symptom in infants is stridor, which is a high-pitched, harsh sound heard predominantly during inhalation. This noise results from air being forced through a narrowed or partially blocked segment of the voice box. The severity of the stridor often depends directly on the degree of airway narrowing caused by the extra tissue.
Voice changes, medically termed dysphonia, are also a frequent consequence, presenting as persistent hoarseness or a weak, breathy cry. The duplicated or webbed tissue prevents the true vocal folds from vibrating normally or closing completely, impairing sound production. Additionally, infants may exhibit feeding difficulties, such as choking or coughing during meals, because the protective function of the larynx is compromised. Severe cases may lead to respiratory distress, cyanosis, or poor weight gain, which are signs that the child is struggling to breathe adequately.
Medical Diagnosis and Management
Diagnosis
The identification of congenital laryngeal anomalies requires specialized medical evaluation, most commonly involving a procedure called laryngoscopy. An otolaryngologist, or ENT specialist, uses a thin, flexible scope passed through the nose (flexible laryngoscopy) or a rigid scope under general anesthesia (direct laryngoscopy) to directly visualize the airway. This procedure allows the doctor to confirm the presence, size, and exact location of any extra tissue, webs, or cysts. The degree of airway obstruction is also assessed during this examination.
Management
Management strategies depend entirely on the severity of the symptoms and the extent of the anomaly. For mild cases of duplication or small webs that do not cause significant breathing or feeding problems, watchful observation may be appropriate. When the anomaly causes life-threatening respiratory distress or failure to thrive, surgical intervention is necessary to secure the airway. Procedures may include endoscopic excision to remove duplicated tissue or cysts, or specialized surgical techniques to treat laryngeal webs, such as using a laser or performing an open reconstruction to restore a functional airway and voice quality.