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FIGURE 1 (See color insert.) Bilateral collapse of the nasal rim that is frequently observed during inspiration in patients with obstructive sleep apnea-associated nasal resistance. Source: Photograph courtesy of Kannan Ramar, M.D.

Class 1 Class 2 Class 3 Class 4

FIGURE 2 Mallampati classification system based on visualization of posterior oropharyngeal structures. Class 1, soft palate, fauces, uvula, anterior and posterior pillars visible; Class 2, soft palate, fauces and uvula visible; Class 3, soft palate and base of uvula visible; Class 4, soft palate not visible.

FIGURE 2 Mallampati classification system based on visualization of posterior oropharyngeal structures. Class 1, soft palate, fauces, uvula, anterior and posterior pillars visible; Class 2, soft palate, fauces and uvula visible; Class 3, soft palate and base of uvula visible; Class 4, soft palate not visible.

and predispose to obstruction during sleep. Many clinical studies have taken different measures of pharyngeal and craniofacial morphology and found associations between them and the presence of sleep apnea. Their utility however, has been notably impaired by their lack of simplicity and practicality at the bedside.

One measure used in the assessment is the Mallampati score (Fig. 2). Designed originally by anesthetists to grade intubation difficulty, the Mallampati grade correlated well with the severity of RDI: r = 0.34, p < 0.001 (117). In another study comparing apneic versus nonapneic patients, sleep apnea patients more often had a Mallampati score of 3 or 4 (78.8% vs. 46%, p < 0.001) (112).

Two other pharyngeal measurements that were independently associated with sleep apnea: tonsillar enlargement (OR 2.6) and lateral narrowing of the pharyngeal wall (OR 2.0) (Fig. 3) (118). Other potentially useful pharyngeal measures include tongue size (118), uvula size (118,119), and palatal height (112,114). "Scalloping" or dental impressions at the edge of the tongue may indicate the presence of an enlarged tongue that habitually presses against the teeth.

FIGURE 3 (See color insert.) Lateral narrowing of the pharyn-geal wall. Source: Photograph courtesy of Kannan Ramar, M.D.

Lateral Narrowing

Retrognathia, micrognathia, and overbite (120) are craniofacial features that capture jaw factors that are associated with a restricted posterior pharynx. These are recognized qualitatively by noting the relative size of the jaw to the maxilla, forward protrusion of the upper teeth over the lower teeth, and absent lower teeth that were surgically removed due to crowding. Quantitative measures of these features are typically obtained by cephalometric radiographs and may be useful in modifying disease probability.

Other Features in the Examination

There is no intention of ignoring other features of the physical examination, as no one feature or collection of findings is ever fully sensitive and specific for sleep apnea and since the physician-patient encounter is designed to do more than just capture a suspected diagnosis. A respiratory, cardiovascular, and neurologic examination can contribute to the sleep workup. A normal neurological examination is particularly important in a patient suspected of having restless legs syndrome and/or PLMD with an emphasis on spinal cord and peripheral nerve function. Similarly, a normal peripheral vascular examination would exclude pathology that might be mistaken for restless legs syndrome.

Sleep Apnea

Sleep Apnea

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