15/04/2021
➡️ What is Pinna ?
The auricle, also known as pinna, is a wrinkly musculocutaneous tissue that is attached to the skull and it functions to capture sound. The auricle is mostly made up of cartilage that is covered with skin. There are two aspects of the auricle: and medial (inner) and lateral (outer). The medial aspect of the ear lobe is attached to the skull and has no major practical significance.
The lateral aspect is concave and presents numerous grooves and ridges. The outer rim of the auricle is called the helix, which then inferiorly ends as soft tissue known as the lobule of auricle (or ear lobe). The helix has three parts: crus, spine, and tail. The crus is the anterosuperior convex arch the helix, the spine the thick superior part of the helix, while the tail is continuous with the lobule. Parallel to the helix is another convex curvature referred to as the antihelix, which has two parts: the triangular fossa bound by the crus of the helix and the antihelix; and the crura of the antihelix which is the widening of the antihelix directed posteriorly toward the helix.
The center of the auricle has a fossa that is continuous with the external acoustic meatus called the co**ha of the auricle. This co**ha is covered with a triangular cartilaginous process called the tragus. The base of the tragus is attached to facial skin, whereas its apex partially covers the entrance to the external acoustic meatus. Opposite to the tragus, there is also a cartilaginous elevation above the lobule called antitragus.
➡️ Congenital Anomalies of Pinna and External canal
Anamolies of Pinna and external auditory canal can be termed as microtia and congenital aural atresia respectively.
☑️ Microtia: is defined as the abnormal development of the Pinna resulting in a malformed auricle. The deformities caused could range from mild distortion of the anatomic landmarks to the complete absence of auricle.
☑️Congential aural atresia: is defined defined as a failure of development of external auditory canal. Congential aural atresia is always associated with a certain degree of microtia.