Oral Cavity and Pharynx

A. Anatomy and physiology

  1.The oral cavity plays a crucial role in articulation and deglutition. The oral cavity includes the lips, oral mucosa, tongue, base of the tongue,   floor of the mouth, alveolar ridges, and hard and soft palates. The pharynx is divided into the nasopharynx, oropharynx, and hypopharynx. Swallowing is a complex task involving soft palate elevation, elevation and retrusion of the tongue, laryngeal elevation, glottic closure, epiglottic retroflexion, and pharyngeal/esophageal peristalsis.

2.Waldeyer’s ring is a ring of lymphoid tissue in the superior pharynx. It is composed of the lingual tonsils, palatine tonsils, and adenoids.

B. Congenital disorders

1.A variety of congenital abnormalities can affect the oral cavity and pharynx and are often associated with genetic syndromes. The Pierre-Robin sequence includes micrognathia, glossoptosis, and a U-shaped cleft. A variety of syndromes such as Apert craniosynostosis, Crouzon craniosynostosis, Treacher Collins syndrome, and velocardiofacial syndrome may also create breathing and swallowing problems through midface abnormalities. Airway obstruction and feeding difficulties can be treated with prone positioning, glossopexy, mandibular advancement, closure of the cleft palate, or tracheostomy

2.Cleft lip and palate. Clefts form as a result of failed fusion of the midface processes during embryogenesis. Clefts may be complete or incomplete, unilateral or bilateral, and can involve the primary and/or secondary palates. Patients with cleft lip and palate deformities should be managed by a multidisciplinary cleft team that can address feeding, hearing, respiratory, cosmetic, speech, and psychosocial issues. Cleft lips are usually closed during the first year of life, and cleft palate surgery is undertaken between 6 months and 2 years of life. These procedures are staged and may require multiple surgeries as the child ages.

C. Trauma

Mandible fractures (MFs) occur most commonly at the angle and parasymphyseal regions of the mandibular body and at the condylar neck (Plast Reconstr Surg 2006;117:48e). Panorex radiographs are usually sufficient to diagnose MF and visualize postreduction. However, cervical spine radiographs and/or CT scan of the face and spine should be performed if maxillofacial and spinal injuries are also suspected. MFs are not surgical emergencies and should be addressed after stabilization of life-threatening conditions in the multiply injured patient. Fixation within 3 days has been shown to result in more favorable outcomes (Laryngoscope 2005;115:769). Minimally displaced fractures can be treated by closed reduction and external fixation [mandibulomaxillary fixation (MMF), or “wiring the jaw shut”]. MMF is less involved and less expensive (J Oral Maxillofac Surg 2000;58:1206; discussion, 1210) but requires fixation for 4 to 8 weeks. Open reduction and internal fixation with lag screws and/or plates allows for more precise reduction and is useful in treating complex or comminuted fractures. Although MF is considered a contaminated fracture due to oral flora, a recent study demonstrated no increased benefit from postoperative antibiotics when administered in uncomplicated MF (J Oral Maxillofac Surg 2001;59:1415). Complications of MF include wound infection, malocclusion, nonunion, tooth loss, temporomandibular joint ankylosis, and paresthesias.

D. Infectious/inflammatory disorders

  • Ulcers in the oral cavity are common and are usually related to viral infections, nutritional deficiencies, or glandular changes. Treatment is generally supportive, although a variety of oral rinses are available that contain antifungals, antihistamines, antibiotics, steroids, and coating agents.
  • Tonsillopharyngitis is caused by bacteria in approximately 40% and 10% of children and adults seeking medical care, respectively. Of those, group A β-hemolytic streptococci are by far the most common pathogens (Ann Emerg Med 1995;25:390). Due to the high incidence of nonbacterial tonsillopharyngitis and to minimize unnecessary antibiotic therapy, new validated guidelines have emerged that recommend antibiotic treatment for only rapid test–positive or throat culture–positive cases (JAMA 2004;291:1587, Ann Intern Med 2001;134:509). Because β-hemolytic streptococci have never shown resistance to penicillin, the recommended antibiotic is still penicillin (oral or intramuscular), with erythromycin reserved for penicillin-allergic patients. Current guidelines recommend tonsillectomy with or without adenoidectomy in children with six or more episodes of tonsillopharyngitis per year or three episodes per year for 2 years.
  • Peritonsillar abscess (PTA) refers to purulence between the tonsil bed and capsule. It is characterized by severe throat pain, unilateral swelling of the soft palate, trismus, drooling, and a muffled “hot potato voice.” The physical exam reveals a bulging erythematous tonsil and soft palate with uvular deviation. Needle aspiration or incision and drainage is the recommended treatment of PTA. In young patients who will not tolerate an awake incision and drainage or in whom recurrence of PTA is suspected, an immediate (Quinsy) tonsillectomy is indicated.
  • Retropharyngeal abscesses occur primarily in children under the age of 2 years. The retropharyngeal space extends from the cranial base to the mediastinum and becomes infected from suppurated retropharyngeal lymph nodes.Children usually present with irritability, fever, stiff neck, muffled speech, and cervical lymphadenopathy. Examination reveals unilateral posterior pharyngeal swelling. A CT scan with contrast can help to delineate the extent of infection. Oral intubation followed by transoral incision and drainage is the treatment of choice.
  • Parapharyngeal space abscess occurs when purulence collects posterolateral to the pharynx and may track down the carotid sheath into the mediastinum. Patients present with fever, leukocytosis, and pain. Treatment consists of aggressive antibiotic therapy. Often, an external surgical approach is necessary for treatment.

E. Obstructive sleep apnea (OSA)

Obstructive sleep apnea (OSA) refers to dysfunctional respiration during sleep due to airway obstruction. OSA is thought to be an underdiagnosed and undertreated entity in both adults and children. Symptoms of OSA in children often include behavioral, learning, and growth problems, whereas OSA in adults is usually manifest by excessive daytime sleepiness. Untreated OSA can lead to pulmonary hypertension and cor pulmonale in both age groups. The most common cause of OSA in children is adenotonsillar hypertrophy, whereas in adults the most common cause is obesity. Overnight polysomnography is the gold standard for diagnosing OSA. Treatment of OSA in children is mainly surgical (adenotonsillectomy), whereas in adults OSA is successfully treated with continuous positive airway pressure (CPAP). Surgery (uvulopalatopharyngoplasty, tongue base reduction, maxillomandibular advancement, or tracheostomy) is reserved for refractory cases.