The Journal
The genioglossus (GG) muscles response to
partial oropharyngeal occlusion was studied in
age matched, healthy awake men (n = 16) and
women (n = 15). A miniature balloon was placed
in the retroglossal pharynx, and the GG's
electromyographic (EMG) reflexive response
was evaluated in different body postures. It was
assumed that inflating the pharyngeal balloon
and changing the body posture from upright to
supine would increase pharyngeal airway
resistance. The hypothesis was that the change
in airway resistance would elicit a different
response in the GG muscle depending on sex.
The results showed that GG activity during
natural breathing was higher in women than in
men. GG EMG activity did not change upon
inflation of the balloon in women. In contrast,
when the balloon was inflated in the men, the
GG's basal activity increased in both the upright
and the supine positions. Women appeared to
show a higher GG baseline EMG activity during
spontaneous breathing at rest, while men were
more responsive to the partial occlusion of the
47
pharyngeal airway (Nanda, Eung; 2002) .
A study was done by Siddek Malkoc; in 2005 to
evaluate the reproducibility of airway
dimensions and tongue and hyoid positions on
lateral cephalometric radiographs. Three lateral
cephalograms each of 30 patients were
obtained in natural head positions at 30 minute
intervals. Twelve measurements, including
pharyngeal airway dimensions and tongue and
hyoid positions, were taken. The relationships
between 3 sets of measurements were
evaluated by using repeated analysis of
variance, Dahlberg’s method error formula, and
correlation coefficient. The study concluded
that airway dimension and tongue and hyoid
position measurements are highly reproducible
on natural head position cephalograms 48 .
Associations of Class II malocclusions and
vertical growth pattern with obstruction of the
upper and lower pharyngeal airways and mouth
breathing have been suggested (De Freatus;
45
2006).This implies that these malocclusion
characteristics have a predisposing anatomical
factor for these problems. Therefore a study
was designed to compare upper and lower
pharyngeal widths in patients with untreated
Class I and Class II malocclusions and normal
and vertical growth patterns. The sample
comprised 80 subjects divided into 2 groups: 40
Class I and 40 Class II, subdivided according to
growth pattern into normal and vertical growers.
The upper and lower pharyngeal airways were
assessed according to McNamara’s airways
analysis. The results showed that the upper
pharyngeal width in the subjects with Class I
and Class II malocclusions and vertical growth
patterns was statistically significantly narrower
than in the normal growth pattern groups. The
study concluded that subjects with Class I and
Class II malocclusions and vertical growth
patterns have significantly narrower upper
pharyngeal airways than those with Class I and
Class II malocclusions and normal growth
patterns. However, malocclusion type does not
influence upper pharyngeal airway width, and
malocclusion type and growth pattern do not
influence lower pharyngeal airway width 57 .
A study was conducted in 2007 by Kirjavamen
to evaluate the effects of cervical headgear
treatment of Class II division 1 malocclusion on
upper airway structures in children. Forty
children aged 9.1 (7.2–11.5) years with Class II
division 1 malocclusion were treated using a
cervical headgear as the only treatment
appliance. Lateral cephalograms were taken
before and after the treatment. Upper airway
structures were estimated from the
cephalograms. The results were compared to
cross-sectional data of 80 age-matched
controls with a Class I molar relationship.
Results showed a Class I molar relationship
was achieved in all treated children. The Class II
malocclusion was accompanied by a similar or
wider nasopharyngeal space than in the
controls but narrower oro and hypopharyngeal
spaces. The retropalatal area was widened by
Vol. 14 No. 2
May-August 2018