The Journal
A critical review of literature by Ryan, Gallagher
in 1982 concerning the effect of nasal airway
functions upon dentofacial morphogenesis
failed to support a consistent relationship
between obstructed nasorespiratory function
30
and the long face syndrome .
An experiment was designed to test whether
there was a morphologic response to changes
in neuromuscular patterns induced due to
altered mode of respiration in rhesus monkeys
(Vargervik;1984). The neuromuscular changes
were triggered by complete nasal obstruction.
Alteration was triggered again by removal of
obstruction and return of nasal breathing. There
was considerable variation in morphologic
31
response among the animals .
A study by McNamara in 1984 suggested that
lower pharyngeal width be measured from the
intersection of the posterior border of the
tongue and inferior border of the mandible to the
closest point on the posterior pharyngeal wall. It
was felt that a width of the lower pharynx greater
than 15mm suggested anterior positioning of
32
the tongue .
The association between craniocervical
angulation and craniofacial morphology, airway
obstruction by adenoids and craniofacial
morphology and between airway obstruction
and craniocervical angulation was studied. The
observed conclusion were in agreement with
the predicted pattern of associations (Solow;
59
1984) .
Another study by Lowe in 1985 documented the
relationship between tongue muscle
parameters at rest and craniofacial morphology
in adult human subjects with normal and
anterior open bite malocclusions Also, there
was a mandibular rotation and a forward tongue
33
posture to maintain the airway .
A study (Lowe; 1986) quantified the facial
morphology in 25 adult males with obstructive
sleep apnea. These subjects showed a
posteriorly positioned maxilla and mandible, a
steep occlusal plane, over erupted maxillary
and mandibular teeth, proclined incisors, a
steep mandibular plane, a large gonial angle,
high upper and lower facial heights, and an
anterior open bite in association with a long
tongue and a posteriorly placed pharyngeal
wall. Subjects with sleep apnea demonstrated
several alterations in craniofacial form that may
reduce the upper airway dimensions and
subsequently impair upper airway stability 34 .
Fig 8 :Showing increased mandibular plane angle, decreased ramus growth, low tongue
position and large anterior face height which may impair upper airway stability
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Vol. 14 No. 2
May-August 2018