The alar cartilage is a structural component found in the lower part of the human nose. This paired, flexible structure contributes to the shape of the nostrils and the nasal tip, playing a role in both appearance and function.
Anatomical Structure and Location
Composed of hyaline cartilage, the alar cartilages are paired structures situated in the lower third of the nose, forming a significant portion of its external framework. Each alar cartilage has a C-shape, forming the distinct contour of the nostrils and nasal tip.
These cartilages consist of two main parts: the lateral crus and the medial crus. The lateral crus extends outwards, forming the flared side of the nostril, known as the ala. The medial crus is the inner portion that meets in the middle, contributing to the columella, the narrow strip of tissue separating the two nostrils. The superior margin of the alar cartilage connects to the lateral nasal cartilage via fibrous tissue.
Functional Role in Respiration and Appearance
The alar cartilages support both breathing and the nose’s visible form. Regarding respiration, these cartilages support the outer wall of the nostril, the ala, helping to maintain the openness of the nasal valve. This structural support prevents the nostril walls from collapsing inward during inhalation, ensuring a clear airway for airflow.
Beyond respiration, the alar cartilages influence the nose’s aesthetic appearance. Their individual size, shape, and inherent strength directly influence the definition and projection of the nasal tip. The way these cartilages are structured also dictates the overall shape and symmetry of the nostrils.
Modifications and Medical Considerations
The alar cartilage is often a focus in rhinoplasty, a surgical procedure to reshape the nose. Surgeons can precisely reshape, reposition, or augment these cartilages to refine the nasal tip and alter nostril shape. Techniques involve using sutures to modify their contour or cartilage grafts to add volume or support.
Medical conditions can also involve the alar cartilage, notably nasal valve collapse. This condition occurs when the cartilage supporting the nostril is weak or damaged, causing the nostril wall to collapse inward during breathing. Such collapse can impair airflow, leading to breathing difficulties and a sensation of nasal obstruction. Additionally, trauma or injury to the nose can result in fractures or displacement of the alar cartilage, potentially affecting both nasal structure and respiratory function.