The Journal
It was proposed (Birte Melson) that the
influence of deviation in swallowing and
respiratory pattern depends on interaction
35
between genetic and environmental factors .
A study was done by Nancy Ung in 1990 to
quantitatively assess respiratory patterns and
their effects on dentofacial development in 49
subjects ranging from 10-16 yrs. Comparisons
of measured breathing modes and dentofacial
characteristics revealed a weak tendency
among mouth breathers toward a Class II
skeletal pattern and retroclination of maxillary
36
and mandibular incisors.
A research (Luc Tourne; 1990) on long face
syndrome and impairment of nasopharyngeal
airway showed that the switch from a nasal to
an oronasal breathing pattern induces
functional adaptations that include an increase
in total anterior face height and vertical
development of the lower anterior face. It was
also found that individual variations in response
should be expected from the alteration of a long
37
face syndrome patient's breathing mode .
Studies were done to assess the amount of
maxillary and mandibular growth and the
direction of maxillary growth after the
adenoidectomy (Donald Woodside). No
difference was detected in the direction of
maxillary growth between the one who had
undergone adenoidectomy and the controls.
But the amount of mandibular and maxillary
growth was significantly greater in
38
adenoidectomy group .
Studies by Frcke et al (1993) tried to relate
nasal airway, lip competence and craniofacial
morphology and concluded that there was no
relationship between open mouth posture and
obstructed airways. It was shown that some
patients show an open mouth posture even
though the nasal airway adequacy was
39
normal .
A study (Ceylan Oktay; 1996) was done on the
pharyngeal size in different skeletal patterns.
43
Lateral cephalometric headfilms of subjects
with different ANB angles were taken. It had
been observed that two measurements, hy
(most superior and anterior point on body of
hyoid bone) - apw4 (anterior pharyngeal wall
along line intersecting cv4ia and hy) and
oropharynx area measurements, were affected
by the change of ANB angle and two other
measurement, t-ppw (t-Dorsal tongue surface
intersecting occlusal plane, ppw. Posterior
pharyngeal wall intersecting occlusal plane)
and hy-apw2 (apw2: Anterior pharyngeal wall
along line intersecting cv2ia and hy)
measurements, by the sex; and that hy-apw4
measurement and oropharynx area became
smaller with the increase of ANB angle 58 .
Brilliant literature was given regarding the soft
tissue growth of the oropharynx. In general, two
periods of accelerated change (6-9 yrs and 12-
15 yrs) and two periods of quiescence (9-12 yrs
and 15-18 yrs) were identified for pharyngeal
40
soft tissue (Taylor Nelson; 1996) .
Various authors (Trotman, McNamara, Dibbets;
1997) studied the association of lip posture,
sagittal airway size and tonsil size separately
with facial morphology under selected
cephalometric measures. They observed that
open lip posture, reduced sagittal airway and
large tonsils were each associated statistically
with a characteristic but different skeletal
configuration. This association was
proportional. It was concluded that lip posture,
sagittal airway size and tonsil size represent
three different and unrelated phenomenons
with respect to their effects on craniofacial
growth and form 41 .
A cephalometric study was done by Eung Kwon
Pal, Ravindra Nanda in 1997 to establish
relation between pharyngeal length and open
bite. A cephalometric variable, vertical airway
length (VAL) was used and it concluded that
pharyngeal length may be a convenient
indicator to diagnose open bite 42 .
Vol. 14 No. 2
May-August 2018