Dose-dependent effects of mandibular advancement on pharyngeal mechanics and nocturnal oxygenation in patients with sleep-disordered breathing.
OBJECTIVE
To examine dose-dependent effects of mandibular advancement on collapsibility of the passive pharynx and sleep-disordered breathing (SDB).


METHODS
Prospective, randomized study.


METHODS
University hospital.


METHODS
Thirty-seven adult patients with SDB.


METHODS
Oral appliances with 2-, 4-, and 6-mm advancement of the mandible.


RESULTS
Overnight oximetry was performed with and without oral appliances. Each 2-mm mandibular advancement coincided with approximately 20% improvement in number and severity of nocturnal desaturations. Percentages of patients producing a > 50% improvement rate of the number of desaturations were 25%, 48%, and 65% with use of oral appliances with 2-, 4-, and 6-mm mandibular advancement, respectively. Static pharyngeal mechanics were evaluated in six completely paralyzed patients with SDB under general anesthesia with and without the oral appliances. Advancement of mandibular position was found to produce dose-dependent closing pressure reduction of all pharyngeal segments. Normalization of nocturnal oxygenation was associated with negative closing pressure, especially at the velopharynx.


CONCLUSIONS
We conclude that improvement of both nocturnal oxygenation and pharyngeal collapsibility significantly depends on the mandibular position.
Kato
J
J
Department of Oral Surgery, Chiba University School of Medicine, Chiba, Japan.
Isono
S
S
Tanaka
A
A
Watanabe
T
T
Araki
D
D
Tanzawa
H
H
Nishino
T
T
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002940:Circadian Rhythm; D006785:Hospitals, University; D006801:Humans; D019186:Mandibular Advancement; D008875:Middle Aged; D010092:Oximetry; D010102:Oxygen Inhalation Therapy; D010614:Pharynx / Q000503:physiopathology*; D011446:Prospective Studies; D012891:Sleep Apnea Syndromes / Q000097:blood / Q000503:physiopathology* / Q000628:therapy; D016896:Treatment Outcome