Sleep apnea (or sleep apnoea in Great Britain, is a sleep disorder characterized by abnormal pauses in breathing or instances of abnormally low breathing, during sleep. Each pause in breathing, called an apnea, can last from a few seconds to minutes, and may occur 5 to 30 times or more an hour. Similarly, each abnormally low breathing event is called a hypopnea. Sleep apnea is diagnosed with an overnight sleep test called a polysomnogram, or "sleep study".
Regardless of type, an individual with sleep apnea is rarely aware of having difficulty breathing, even upon awakening. Sleep apnea is recognized as a problem by others witnessing the individual during episodes or is suspected because of its effects on the body (sequelae). Symptoms may be present for years (or even decades) without identification, during which time the sufferer may become conditioned to the daytime sleepiness and fatigue associated with significant levels of sleep disturbance.
Sleep apnea affects not only adults but some children as well. In other words, common effects of sleep apnea include daytime fatigue, a slower reaction time, and vision problems. Moreover, patients are examined using “standard test batteries” in order to further identify parts of the brain that are affected by sleep apnea. Tests have shown that certain parts of the brain cause different effects. The “executive functioning” part of the brain affects the way the patient plans and initiates tasks. Second, the part of the brain that deals with attention causes difficulty in paying attention, working effectively and processing information when in a waking state. Thirdly, the part of the brain that uses memory and learning is also affected.
Due to the disruption in daytime cognitive state, behavioral effects are also present. This includes moodiness, belligerence, as well as a decrease in attentiveness and drive. These effects become very difficult to deal with, thus the development of depression may transpire. Finally, because there are many factors that could lead to some of the effects previously listed, some patients are not aware that they suffer from sleep apnea and are either misdiagnosed, or just ignore the symptoms altogether.
Fifteen percent of all teenagers in the United States undergo orthodontic treatment. Craniofacial Risk Index (CRI) scores, calculated from the radiographs routinely obtained on all orthodontic patients, correctly classified 80% of apneic and 78% of non-apneic adult snorers into high- and low-Respiratory Disturbance Index (RDI) groups. (Sleep apnea is a temporary suspension of breathing during sleep, with potentially serious consequences.) Researchers at Case Western Reserve University (Cleveland, OH) wondered whether similar radiographic use could identify adolescent orthodontic patients with high RDI scores.
The investigators studied the case histories of 590 patients between 7 and 18 years of age attending the orthodontic clinic at Case Dental School. They recorded age, gender, height and weight (abstracted from patient chart) along with tongue length and hyoid-to-mandibular-plane distance (measured from lateral cephalograms) in a linear model to generate a CRI score. The 30 patients with the highest and 30 patients with the lowest CRI scores were asked to undergo unattended in-home sleep monitoring to determine their RDI score.