Dental Asia Jan/Feb 2019

Dental Management DENTAL ASIA JANUARY / FEBRUARY 2019 22 O bstructive sleep apnoea (OSA) is a common sleep disorder characterised by repetitive episodes of upper airway obstruction with efforts to breathe, resulting in reduction of blood oxygen saturation and ending with sleep arousal. OSA has been linked to a number of morbid conditions such as stroke, hypertension, cardiovascular disorders, increased road traffic accidents, secondary depression, anxiety, sexual dysfunction, and overall mortality. 1-3 The mechanism by which obstructive sleep apnoea condition develops is believed to be multifactorial and complex; a common etiology is the narrowing of the upper airway due to the presence of excessive soft tissues like an enlarged tongue, inflamed adenoids/ tonsils or excessive accumulation of adipose tissue in the neck area inducing pressure on the dimensions of the upper airway 4 . The condition may also develop due to structural abnormalities in the head and neck area, such as retrognatic jaw position developing into a narrow airway space 5 (Fig. 1). Prevalence and Symptoms The prevalence of OSA is approximately of 3-7% in adult males and 2-5% in adult females, and the prevalence estimates are similar to data reported worldwide - common symptoms include snoring, excessive daytime sleepiness among others 6-7 . The complaint of snoring precedes the complaint of daytime sleepiness, and the intensity increases with weight gain and bedtime alcohol intake. Excessive daytime sleepiness is one of the most common clinical manifestations of obstructive sleep apnoea. Obstructive sleep apnoea is usually associated with disturbed sleep architecture, the more severe the sleep fragmentation, the more likely that daytime sleepiness will be reported. Diagnosis To diagnose OSA, a comprehensive sleep evaluation is needed, including a full medical history, sleep questionnaires, phys i ca l exami na t i on and s l eep testing. The standard diagnostic test for obstructive sleep apnoea is the o v e r n i gh t po l y s omnog r aph y. I t involves the recording of multiple physiologic signals during sleep, including electroencephalograph (EEG), electrooculogram (EOG), electromyogram (EMG), oronasal airflow, oxyhaemoglobin saturation, and respiratory effort measurement among other measures. The severity of obstructive sleep apnoea is measured by the apnoea-hypopnoea index (AHI), obtained by sum of apnoeas and hypopnoeas per hour of sleep. An AHI lower than five events per hour of sleep is normal, an AHI of five to fifteen events per hour of sleep indicates mild OSA, an AHI of 15-30 events per hour of sleep indicates moderate OSA, and an AHI greater than 30 events per hour of sleep indicates severe OSA 8 . Treatment Treatment options include the use of continuous positive airway pressure (CPAP), it has been considered the standard treatment option for OSA with some limitations including patient tolerance and cumbersome fitting of the device. The use of oral appliances has evolved as a practical alternative to CPAP, especially in cases with mild to moderate OSA. Such treatment modality has been shown to be effective in clinical practice 9 . Other treatment modalities include weight loss, uvulopalatopharyngoplasty (UPPP) and maxilla-mandibular advancement surgery among others 10 . Oral Appliances for OSA Oral appliances are classified as mandibular advancement devices (MAD) and tongue retainer devices (TRD). The primary action of MAD is to reposition and maintain the lower jaw forward during sleep 11 . Different oral appliances’ designs are available and their differences rely on material of fabrication, connectors, The Dentist’s Role in the Management of Obstructive Sleep Apnoea By Dr. Leopoldo P. Correa ; BDS, MS Tufts University School of Dental Medicine Boston, Massachusetts. USA Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5