Oral mandibular advancement devices are becoming an increasingly important
treatment alternative for obstructive sleep apnea (OSA). The first aim of t
he study was to determine whether a new oral elastic mandibular advancement
device (EMA) prevents pharyngeal air-way closure during sleep in patients
with OSA. The second aim of the study was to determine if the polysomnograp
hic response to the oral mandibular advancement device: was dependent on th
e site of airway closure. Overnight polysomnograms were performed in 28 unt
reated OSA subjects with and without EMA. A third polysomnogram was perform
ed in 12 of the subjects to determine the site of airway closure without th
e device. Site of airway closure above or below the oropharynx was determin
ed by measuring the respective presence or absence of respiratory fluctuati
ons in oropharyngeal pressure during induced occlusions in non-rapid eye mo
vement (NREM) sleep, Mean apnea-hypopnea: index (AHI) was 52.6 +/- 28.2 (SD
) events/h without the device and 21.2 +/- 19.3 events/h with the device, N
ineteen subjects (68%) had at least a 50% reduction in AHI with the device.
The change in AHI with the, device (AHI without device - AHI with device)
was directly related to the AHI without the device. All three subjects with
airway closure in the lower pharyngeal airway had a greater than 80% reduc
tion in AHI with the device. Two of the nine subjects with airway closure i
n the velopharynx had a similar therapeutic response. The results show the
effectiveness of EMA in the treatment of OSA, The results also indicate tha
t polysomnographic severity of OSA and the site of airway closure should no
t be used to exclude patients from this oral device treatment.