Treating Patients with Sleep Disorders

The first clinics dedicated to sleep medicine appeared in the 1970s, primarily for the treatment of obstructive sleep apnea (OSA). Caused by complete or partial obstruction of the upper airway, OSA is characterized by repetitive episodes of shallow or paused breathing during sleep. These episodes are called apneas (literally, “without breath”), defined as at least a 90% drop in airflow for 10 seconds or longer.¹ A hypopnea, involving at least a 30% drop in airflow for 10 seconds or longer, is associated with more than 3% blood oxygen desaturation. To be categorized as obstructive, the episodes must be accompanied by snoring, increased oronasal flow flattening, and/or thoraco-abdominal paradoxical respiration.² It is often the snoring that leads a patient to seek treatment. When the apneas and hypopneas are accompanied by sleepiness and other daytime symptoms, the problem is known as obstructive sleep apnea-hypopnea syndrome.³

Although orthodontists have noted improvements in upper airway dimensions as a result of their treatment since the early days of the specialty, it was not until the last 20 years or so that the airway became a direct treatment objective. Techniques such as rapid maxillary expansion were initially explored as means to correct anterior open bites by the elimination of obligate mouthbreathing. Clinicians noted that when the upper airway was expanded and the open bites were resolved, the patients or their parents also mentioned that the snoring was “cured.”