|Study||Participants||Interventions||Comparisons||Outcomes||Study design||Three-dimensional||Short description of the study||
Main findings regarding
airway volume changes
|Ono et al. ||12 adult males, mean (SD) age: 27.8 (3.19) years, no sign of disorders related to the upper airway.||Three head/body positions were evaluated: supine, supine with the head rotated and lateral recumbent.||Morphologic, dimensional and volume changes in relation to head/ body positions.||Effects of head/body positions on the morphology, dimension and volume of the upper airway.||Non-randomized controlled trial. Prospective study.||MRI||This study deals with the effects of head and body position changes (supine, supine with the head rotated and lateral recumbent) on upper airway dimension and volume in patients examined with three-dimensional MRI.||The study shows a significant increase in volume in the retroglossal region of oropharynx when the subject rotated his head to left in the supine position and when changed from the supine to the lateral recumbent position.|
|Pirilä-Parkkinen et al. ||29 children with SDB (14 boys, 15 girls), mean (SD) age: 7.3 (1.37) years and a control group of 29 age- and gender-matched healthy children.||Three different head postures were evaluated: neutral, extension, and flexion.||Changes of pharyngeal cross-sectional airway area (mm2) in relation to changes of head postures.||Effects of different head postures on the pharyngeal airway size.||Non-randomized controlled trail. Prospective study.||MRI||This study deals with patients in different head postures (neutral, extension and flexion) in MRI and the effect on the pharyngeal airway in 29 children with SDB and 29 asymptomatic control children.||The hypopharyngeal airway in the SDB group was significantly increased with head extension compared to neutral head posture and the increase was higher for the SDB group than in the asymptomatic group.|
et al. 
|12 subjects (8 male and 4 female), mean (SD) age: 26.13 (3.21) years, no sign of disorders related to the upper airway.||4 different jaw, head and body positions were evaluated: jaw protrusion, supine with jaw protrusion, supine-head rotation with jaw protrusion and lateral decubitus with jaw protrusion.||Changes in jaw, head and body positions in relation to changes in A-P dimension, lateral dimension, cross-sectional area, and volume of oropharynx.||Effects of different jaw, head and body positions on the A-P dimension, lateral dimension, cross-sectional areal and volume cm3 of the pharyngeal airway at the retropalatal and retroglossal region.||Non-randomized controlled trail. Prospective study.||MRI||
The study looks at the effect of altering head and body position on the oropharyngeal airway dimension and volume examined by MRI. The four different jaw, head and body positions:
1) supine without jaw protrusion, 2) supine with jaw protrusion, 3) supine with head rotation and jaw protrusion and 4) laterally recumbent position with jaw protrusion.
|The results of the study show that jaw protrusion increases the volume (cm3) of oropharynx at the level of retropalatal region and retroglossal region compared with nonprotruded positions.|
et al. 
|60 female subjects, mean (SD) age: 40,4 (17,8) years, no airway pathology noted on CBCT.||Closed and open jaw positions were evaluated.||Changes in open and closed jaw position in relation to volume of the nasal cavity, nasopharynx, and oropharynx; the soft palate; the soft-tissue thickness of the airway; and the most constricted area of the airway.||Effects of open and closed jaw positions on the volume of the upper airway.||Non-randomized controlled trail. Retrospective study.||CBCT||This study looked at the influence of open and closed jaw positions on the upper airway dimensions in patients who were undergoing diagnosis and treatment of temporomandibular disorders.||The results from this study showed that open jaw position compared to closed jaw position cause a significant increase in nasopharynx whereas the nasal cavity volume, oropharynx volume, and soft palate area decrease.|
SDB = sleep-disordered breathing; MRI = magnetic resonance imaging; CBCT = cone-beam computed tomography; SD = standard deviation.