tailieunhanh - Ebook Facial flap surgery (E): Part 2

Part 2 book “Facial flap surgery” has contents: Anatomy and biomechanics, repair of the tragus, antitragus, and lobule, bioanatomy and biomechanics, repair of the upper lip subunits, rotation and advancement flaps, repair of medial canthal wounds, transposition flaps, island pedicle flaps, eyebrow reconstruction, and other contents. | CHAPTER 8 Ear ANATOMY AND BIOMECHANICS The ear is a complex cartilaginous structure enveloped by a thin fascia. The anterior surface is highly convoluted with a rich topography (Fig. ). The skin here is stretched tight like a drum and provides minimal resource for adjacent tissue transfer. The helical rim creates a sharp reflection posterior to which the skin and subcutaneous tissues are somewhat thicker, more richly vascular, and mobile. The lower helix and lobule contain abundant fat and are loose and freely mobile. Toward the reflection with the mastoid scalp, the ear receives tendinous muscular fibers from the auricular musculature which are more adherent to the perichondrium. 374 375 Figure Nomenclature of the ear The vascular supply of the ear is rich and redundant (Fig. ). The majority of the posterior surface of the ear and the lobule are supplied by branches of the posterior auricular artery, a direct branch off of the external carotid. The superior helical rim, the triangular fossa, and the scapha are supplied by a superior auricular branch off of the superficial temporal artery. The conchal bowl is largely supplied by perforators from the posterior auricular artery. 376 Figure Arterial supply of the ear 377 Sensory innervation of the ear is from three sources (Fig. ). The majority of the ear is innervated from the greater auricular nerve that arises from the second and third cervical nerves and passes over the sternomastoid to arrive at the ear right at the base of the lobule. Portions of the anterior surface of the ear and superior ear are innervated by the auriculotemporal nerve, which is a direct branch from the mandibular nerve of the fifth cranial nerve. The inner conchal bowl and outer canal derive sensory input from cranial nerves VII, IX, and .