Fig 1.
A—T1-weighted MR image of head-neck region of a newborn infant showing head-tilt angle between the occipito-ophisthion-C7 spinous process, AP diameters of airway at the level of palate (1) and tongue (2) in mid-sagittal plane. B—Axial T1-weighted MR image of head-neck region of a newborn infant showing lateral diameter of airway at the tongue level (3).
Fig 2.
A—Sagittal T1-weighted MR image of head-neck region of a newborn-infant showing obstructed airway at the tongue level. B—Sagittal T1-weighted MR image of head-neck region of a newborn-infant showing a patent airway.
Fig 3.
Box-plot diagram of head-tilt angle of patent airway as compared to that of obstructed airway.
The median head-tilt angle associated with patent airway (125.3° ± 11.9°) was significantly different from median head-tilt angle (108.2° ± 17.1°) associated with an obstructed airway (p = 0.0045).
Fig 4.
Logistic regression analysis of airway patency versus head-tilt angle shows that the probability of a patent airway progressively increases with increasing head-tilt angle.
There is at least a 95% probability that an airway will be patent between head-tilt angle 144–150°. Y-axis represents the proportion of patent airways with standard error of proportion and X-axis represents 15° bins of head-tilt angles.
Table 1.
Correlation between Head-tilt Angle of Patent Airways and Age, Weight, and Gestational Age of Newborn Infants.
Table 2.
Logistic Regression Model of Patent Airway vs Head-tilt Angle.