- Abstract : A normal modified type of
swallow is described, the function of which is
to open the pharyngotympanic tube. It is
associated with clicking of the ears. The tensor
veli palatini, the levator palatini and the
superior constrictor muscles appear to be the
muscles involved, as it can occur without
swallowing or movement of the tongue, or
speaking. This modified swallow has been called
the 'superior constrictor swallow', and it is
demonstrated by productions of typical frames
from a cine film. Sniffing, yawning and
normal swallowing can occur with or without
opening of the pharyngotympanic tubes, but this
normal modified swallow (SCS) must be initiated
to produce opening of the tubes. The change in
middle-ear pressures with clicking is well shown
with tympanometry. Modified swallow, largely
involving the inferior constrictor muscle, may
also occur.
A normal modified type of swallow is described,
the function of which is to open the
pharyngotympanic tube. It is associated with
clicking of the ears. The tensor veli palatini,
the levator palatini and the superior
constrictor muscles appear to be the muscles
involved, as it can occur without swallowing or
movement of the tongue, or speaking. This
modified swallow has been called the 'superior
constrictor swallow', and it is demonstrated by
productions of typical frames from a cine film.
Sniffing, yawning and normal swallowing
can occur with or without opening of the
pharyngotympanic tubes, but this normal modified
swallow (SCS) must be initiated to produce
opening of the tubes. The change in middle-ear
pressures with clicking is well shown with
tympanometry. Modified swallow, largely
involving the inferior constrictor muscle, may
also occur.
-
- The normal swallow, initiated from the
buccal cavity, can be broadly said to comprise:
first, the superior constrictor muscle with
closure of the post-nasal space; then, the
middle constrictor muscle with elevation and
closure of the larynx; and then,, the inferior
constrictor muscle with relaxation of the
cricopharyngeus muscle. The basic normal swallow
will be termed for reference 'the middle
constrictor swallow', and called MCS.
-
- A modified swallow can occur, involving
mainly the superior contrictor muscle from
stimulation of receptors above the palate, which
will be termed 'the superior constrictor
swallow'. Another type may occur from
stimulation of receptors in the lingual
tonsil-epiglottis area involving mainly the
inferior constrictor muscle which will be termed
'the inferior constrictor swallow, as previously
reported (Gray, 1983).
-
- The 'superior constrictor swallow' (called
the SCS for this article) will now be
considered.
-
- The SCS is a normal co-ordinated muscle
movement complex involving mainly the tensor
veli palatini muscle and partly the levator yell
palatini and the superior constrictor muscles,
the function of which is to open the
pharyngotympanic tubes. The tensor tympani
muscle is also closely involved. The superior
margin of the superior constrictor muscle passes
just beneath the pharyngotympanic tube between
the tensor and levator levi palatini muscles.
The SCS may be initiated voluntarily but usually
is involuntary. It may occur by itself or be
associated with yawning or the normal
swallow (MCS), but the MCS can occur without the
SCS.
-
- The opening of the pharyngotympanic tube is
appreciated as a 'clicking in the ear'.
-
- This can be initiated.
-
- 1. By change in intra-tympanic pressure
- (a) via glomus tympanicum projections to the
solitary fasciculus (Eden, 1981).
-
- (b) via the tensor tympani and the tensor
veli palatini muscles, which have the same nerve
supply from the Yth nerve nucleus, are
continuous with each other and share part of a
common origin(Lupin, 1969), have closely
correlated electromyographic responses (Kamerer,
1978) and have synergism of action (Proctor,
1967).
-
- 2. By irritation of the post nasal space and
superior aspect of the palate. This is
demonstrated by the continual clicking often
complained of by people following upper
respiratory tract infection.
-
- 3. By sniffing(Gray, 1967; Lamp, 1973;
Gerwat, 1975; Magnuson, 1980; Falk, 1981;
Andreasson et al., 1981). This requires active
movement of the palate as well, for the tubes
may not open with the socalled 'anterior
sniffing'. Magnuson (1980) demonstrated the
active contraction of the tensor tympani muscle
with the tensor veli palatini and momentary rise
in intratympanic pressure just before the sniff
reduced the intra-tympanic pressure.
-
- Sniffing is very common in allergic children
and is particularly associated with the allergic
nasal line (Gray, 1967). There are two kinds of
sniffers-the 'anterior rubbers' and the
'posterior grunters'. The posterior grunters
have an irresistable urge to rub their palates
convulsively on the adenoid area. Snorting or
sniffing is required as part of this muscle
movement. As one child said: 'If I could only
get my toothbrush and rub the back of my palate,
I would be happy'. As part of this muscle action
of sniffing, the SCS may occur, which is helped
by lowering the pressure in the post-nasal space
(Bernoulli's Theorum(Gray, 1967; Gerwat, 1975)),
and causing a decrease in the intra-tympanic
pressure. This makes the ear feel uncomfortable,
and stimulates the reflex to open the tube
(often associated with slight blowing), thus
distending the drum, which is then sniffed in
again. The perpetuation of this alternating
pressure causes stretching and then atrophy of
the elastic fibres of the middle layer of the
drum, allowing the drum to become sucked in more
and more around the ossicles and into the attic.
This is accentuated by the anatomy and shape of
the drum (Gray, 1967).
-
- 4. By voluntary opening, which must be
learned by every diver and pilot. This may
- be assisted by raising the pressure in the
post-nasal space (Valsalva), particularly if
associated with swallowing (augmented Valsalva),
which activates the SCS.
-
- The following investigations demonstrated
the presence of the SCS. The
- author was used as the patient, as he could
cause repeated clicking of the ears with the
mouth held open without swallowing, and he could
correlate the symptoms. This was well
demonstrated by cine film recording and Figs. 2
and 3 are taken from the film of these
movements. Fig 2 shows the mouth open, palate at
rest, and a plug of accumulation of barium in
the bottom of the hypopharynx at the level of
the lower end of C5 vertebra. Fig 3 shows
elevation of the palate and
- closure of the post-nasal space, which was
associated with the deliberate clicking of the
ears. This was confirmed by Dr. P. Sprague, who
performed the cine filming Neither the tongue
nor the epiglottis has moved and there is no
elevation of the hyoid bone. There is elevation
of the barium plug to the upper border of the C5
vertebra with some narrowing of the
hypopharyngeal space, which would only occur
with the superior constrictor contracting by
itself.
-
- The opening of the pharyngotympanic tubes
associated with the clicking (with mouth open
and without swallowing or speaking) was
demonstrated by tympanometry, as seen in Figs. 4
and 5. The positive pressure easily put into the
middle ears was reduced in steps by each click.
Minimal changes occurred with clicking at normal
pressure. Similar return to normal pressure with
swallowing from an initial negative pressure was
shown by Falk (1981). An 'inferior constrictor
swallow' was also able to be demonstrated.
-
- Discussion
-
- The superior constrictor swallow movement is
a normal movement and may be stimulated from the
ear and post nasal space. It also may combine
with other normal occurrences such as
swallowing, yawning and sniffing, or may
be activated voluntarily.
-
- Repeated clicking, which may continue after
a simple upper respiratory infection, can become
extremely worrying. It is often relieved by
antihistamines and nasal decongestants, but it
is important to explain that this clicking is a
normal and important function associated with
swallowing, and that repeated swallowing can be
caused by irritation of parts of the nose and
throat.
-
- The act of yawning with the mouth
open and elevation of the palate is similar to
the procedure depicted in Fig. 3.
-
- The change in normal pressures of the middle
ear with clicking, as shown in this
investigation (Fig. 4), and the demonstration of
temporary increase in intra-tympanic pressure by
Magnuson (1980) in sniffing, strongly suggests
not only that the tensor tympani and the tensor
vei palatini muscles act synergistically
together, but also that the tensor tympani has
an active pulsing effect in the aeration of the
middle ear. A vicious circle may occur with
sniffing, causing a continual high negative
intra-tympanic pressure, accentuated by septal
deviation of the kinked type. Septal deformity
is one of the major factors of ear disease
varying in degree on each side. The combination
of the presence of an allergic nasal line,
sniffing, septal deformity and severe indrawn
ear drum in a child, is usually an indication
for the insertion of an ear drum vent This tides
the child over until, with aging, the sniffing
has ceased and the airway improved, and may
prevent the development of cholesteatoma.
-
- Summary
-
- 1. A normal modified type of swallow is
described, the function of which is to open the
pharyngotympanic tube. It is associated with
clicking of the ears. The tensor veli palatini,
the levator palatini and the superior
constrictor muscles appear to be the muscles
involved, as it can occur without swallowing or
movement of the tongue, or speaking.
-
- 2. This modified swallow has been called the
'superior constrictor swallow', and it is
demonstrated by productions of typical frames
from a cine film.
-
- 3. Sniffing, yawning and normal
swallowing can occur with or without opening of
the pharyngotympanic tubes, but this normal
modified swallow (SCS) must be initiated to
produce opening of the tubes.
-
- 4. The change in middle-ear pressures with
clicking is well shown with tympanometry.
-
- 5. Modified swallow, largely involving the
inferior constrictor muscle, may also
occur.
-
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