Sinopsis
The entire pinna, except its lobule, and the outer part of external acoustic canal are made up of a framework of a single piece of yellow elastic cartilage covered with skin. The latter is closely adherent to the perichondrium on its lateral surface while it is slightly loose on the medial surface. The various elevations and depressions seen on the lateral surface of pinna are shown in Fig. 1.1B.
There is no cartilage between the tragus and crus of the helix, and this area is called the incisura terminalis (Fig. 1.1C). An incision made in this area will not cut through the cartilage and is used for endaural approach in surgery of the external auditory canal or the mastoid (see page 410). Pinna is also the source of several graft materials for the surgeon. Cartilage from the tragus, perichondrium from the tragus or concha, and fat from the lobule are frequently used for reconstructive surgery of the middle ear. The conchal cartilage has also been used to correct the depressed nasal bridge while the composite grafts of the skin and cartilage from the pinna are sometimes used for repair of defects of nasal ala.
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