From hearing loss or nasal hemorrhage to expert management of acute airway emergencies, otolaryngology–head and neck surgery is a surgical subspecialty that focuses on the management of a wide range of disorders of the head and neck. Even at the anatomical boundaries of the head and neck, otolaryngologists are frequently involved in surgical management of both benign and malignant conditions in collaborative efforts with thoracic surgeons in the cervical esophagus or superior mediastinum, ophthalmologists or oculoplastic surgeons in orbital pathology, and neurosurgeons at the skull base. The limits inherent to a single book chapter preclude covering such a broad field comprehensively. Therefore, this chapter will present an overview of selected disease processes in otolaryngology that are of importance to the general surgeon in training. Each section will focus on a specific anatomic subsite of the head and neck because each has a particular anatomy, physiology, and disease processes that make workup and management unique to that head and neck subsite. These sections will address the differential diagnosis of the most common presenting complaints seen in practice. Treatment will focus on both common disorders and urgencies and emergencies that must be recognized early and managed appropriately. Through a targeted history and physical examination, an understanding of the basic anatomy and possible differential diagnoses, and appropriate laboratory or imaging investigations, these common presenting complaints or emergent situations may be logically and efficient distilled to the underlying cause and treated appropriately. Although malignant etiologies may occur in each head and neck subsite and must often be included in the differential diagnosis, for a consistent and comprehensive discussion, the staging and management of malignant head and neck tumors are addressed separately in the final section of this chapter.
DISORDERS OF THE EAR, AUDITORY, VESTIBULAR SYSTEMS, AND TEMPORAL BONE
The ear consists of three anatomically distinct and functionally unique components: the external ear, the middle ear, and the inner ear. The external ear includes the auricle or pinna and the external auditory canal (EAC). The auricle’s height is generally twice its width, and it projects from the lateral aspect of the head at an average of 30 degrees. The auricle is composed of elastic cartilage with tightly adherent perichondrium and overlying skin. The exception is the lobule, which lacks a cartilaginous framework. Functionally, the pinna is important for sound source amplification and localization, most notably in the vertical plane.
The EAC is a curvilinear tubal structure immediately posterior to the temporomandibular joint. The EAC is cartilaginous in its lateral third and bony in its medial two-thirds. The lateral third features hair follicles, sebaceous glands, and ceruminous glands that produce cerumen, or ear wax. Cerumen is a slightly acidic (average pH 6.1) substance with antimicrobial properties that serves to cleanse, lubricate, and protect the EAC from insects and microbial infection. Rarely, sebaceous and ceruminous glands can derive benign or malignant neoplasia. ...