In infants or young children, the narrowest portion of the larynx is at the cricoid cartilage. In a child, an endotracheal tube might pass easily through the vocal cords but not through the subglottic region. The cricoid is the only complete ring of cartilage in the laryngotracheobronchial tree and is therefore nonexepandable. A tight fitting endotracheal tube that compresses the tracheal mucosa at this level may cause edema and result in increased airway resistance at the time of extubation. For this reason, uncuffed endotracheal tubes are usually preferred for infants or young children. As the child matures (age 10 to 12 years of age), the cricoid and thyroid cartilages have grown, eliminating the narrowing of the subglottic area and angulation of the vocal cords.