THE ANATOMY AND PHYSIOLOGY OF HARELIP AND CLEFT PALATE.
_Harelip—Effect of labial muscles on deformity—Structure of os
incisivum and labial segments._
_Cleft palate—Arrangement and action of muscles—Shape
of bony segments—Associated irregularity in shape of
skull—Physiological effects in nutrition, articulation, &c._
The short description of these congenital conditions given in Chapter
I must be now supplemented by a little more exact account from an
anatomico-physiological point of view.
With regard to harelip, if unilateral, but little remains to be said,
except to emphasize the fact that the deformity is not altogether due to
loss of substance, but to a considerable extent to the unbalanced action
of muscles, the equilibrium of which has been disturbed by the fissure.
Thus the orbicularis oris, which should have a sphincter-like action, has
its continuity interrupted, so that when contraction occurs, the effect
will be to widen and evert the edges of the cleft. The muscles acting
upon the corners of the mouth, moreover, will tend to exaggerate the
deformity, and thus all such actions as laughing and crying will have a
similar result.
The margins of the cleft are rounded, and the red mucous border of the
lip passes up for a variable distance on either side, but does not extend
to the apex except in very slight fissures. The upper part of the cleft
in the more serious forms has its margin formed of skin, a fact which
must not be overlooked in planning an operation for its cure, and which
will be again alluded to in the next chapter.
The space between the segments of the lip is usually triangular in shape,
and like an inverted V; it may or may not communicate with the nostril.
In alveolar harelip the alveolus is cleft, as has been already described,
along the endo-mesognathic suture; but the floor of the nose is not
necessarily implicated.
The line of fissure in many instances passes through the maxillary
attachment of the depressor alæ nasi, and the absence of the controlling
influence of this muscle is an important element in the production of the
broad flattened condition of nostril such a common accompaniment of this
deformity, thus affording an explanation of the nasal distortion in cases
where the alveolus is intact. If that structure be also implicated, then
the floor of the nose will be deficient to a greater or less extent, and
the tendency of the nostril to fall away increased.
On raising or making tense either segment of the cleft lip, the existence
of strong reflections of the mucous membrane or frænula will become
evident, in addition to the normal mesial frænum; these are sufficiently
firm to limit the range but not to antagonise completely the action of
the muscular contractions already alluded to. Moreover, unless freely
divided by undercutting they will effectually prevent by their tension
the parts being brought into a state of easy apposition, so necessary in
order to gain primary union.
In bilateral or double harelip the maxillary segments on either side
correspond in every particular with the outer segment in a unilateral
cleft; but the central portion which is continuous with the columna
nasi deserves special notice. It is usually ovoid in shape and stunted,
appearing as if shrunken upwards from the absence of lateral support;
its breadth and length are nearly equal, and there is a small portion
of the red labial margin at the lower part. It is attached on its
deep aspect to the os incisivum by firm muco-fibrous frænula, and in
aggravated cases it appears to project amalgamated with the columna
from the tip of the nose, forming the proboscis-like appendage already
illustrated (Fig. 8).
[Illustration: FIG. 41.—Os incisivum, consisting of two lateral bony
segments, each bearing an incisor. (_Fergusson._)]
The os incisivum has usually a larger superficial area than this
“philtrum” of the upper lip, and hence protrudes beyond it in all
directions. It forms a projecting tubercle, covered by smooth mucous
membrane on its under side, with the central portion of the upper lip
attached anteriorly. In a young child it consists of two little portions
of bone, imperfectly united together, which in the fœtus are represented
by two cartilaginous nodules, mobile on each other, and within each
a separate ossific centre; in other words, it is formed by the two
endognathia. Inside are found the rudiments of a variable number of
teeth; ordinarily in a child’s os incisivum, operated on at the usual age
(viz. one to three months), one finds on laying it open the rudiments of
four teeth, the temporary and permanent central incisors, arranged in
pairs, one above the other. Occasionally, as has been already mentioned
(p. 54), one finds evidence of the development of another incisor on one
or both sides of the projecting tubercle, and directed towards the cleft;
but such is usually imperfectly developed and stunted. In fact, amongst
all the ossa incisiva removed by Sir William Fergusson and now preserved
in King’s College Museum, but few show any traces of the additional
incisor, whilst the common arrangement is to find only the two central
teeth (Fig. 41). In no case is there any evidence of the existence of
more than two bony segments.
The anterior wall of the bone is always badly developed, and most
commonly when displaced the growth of the whole projection is somewhat
impeded, so that it is smaller than in the normal condition.
Its position may vary, being occasionally but little displaced
anteriorly, though in consequence of its slight basis of support, viz.
the antero-inferior extremity of the vomer, it is generally mobile; bands
of muco-fibrous tissue are occasionally seen passing from it to the
maxilla under such circumstances. Every variety of anterior displacement
is met with, until the severest forms alluded to above are reached. If
operative interference be delayed until late in life, the vomer becomes
dense and hypertrophied, and the junction with the os incisivum much
firmer, increasing the subsequent difficulties and dangers of treatment.
More exact details as to the dentition in cases of alveolar harelip have
been already given and discussed in a former chapter (p. 51). It is
interesting to note here, however, that the temporary incisors, both in
the intermaxilla and lower jaw, have a tendency to appear earlier than
usual; I have many times seen incisors in such cases erupted at birth.
* * * * *
Amongst the many contributions to surgery which we owe to the late Sir
William Fergusson, not the least is that interesting account given of
the anatomy of cleft palate, derived from a minute dissection of a case
which came under his observation in the dissecting room. The specimen
was obtained from the mouth of an aged female.[63] The fissure in this
case was one of medium severity, implicating the velum and the posterior
portion of the hard palate. The upper horizontal fibres of the superior
constrictor were more fully developed than under ordinary circumstances,
and would appear to have assisted in shutting off the posterior nares
during deglutition and speech. The tensor and levator palati muscles were
normally situated and developed, and it appeared from this dissection
that the latter muscle was the main factor in drawing the velum upwards
and outwards. Consequently the division of this muscle in some way or
other is absolutely essential where any plastic operation is undertaken
for the closure of the cleft. The palato-glossi and palato-pharyngei
evidently possess the power of drawing the posterior part of the velum
outwards and downwards, but they are by no means so powerful as the
levator.
During muscular repose the edges of the cleft are considerably
approximated to one another; indeed, the posterior halves of the velum
may even touch, and the same condition to a limited degree obtains
during deglutition. Fergusson rightly ascribed the latter effect to the
contraction of the upper portion of the superior constrictor, which we
have already mentioned is hypertrophied, the levator and tensor muscles
being at the same time presumably relaxed. If the edges of the cleft be
irritated, the lateral segment is instantly drawn upwards and outwards,
and disappears as it were, an observation which emphasizes the necessity
for the complete division of the levatores at some period of the
operation.
Where the cleft extends into the bony palate, it is not uncommon to find
the pitch of the palatal segments vary considerably. If the cleft be
incomplete, the sides will be regularly sloped, although the vault may be
higher than usual; whilst in cases of complete cleft, it is not uncommon
to see an excessive upward slope of the bones like a Gothic arch, but not
always symmetrical. Pollock states that “the more complete the cleft, the
nearer the perpendicular are the sides of the palate;” and consequently
when the soft tissues are detached from the bone in uranoplasty the
flaps will fall into position more readily, and in many cases meet
without difficulty in the median line. The following diagrams (Figs. 42
and 43) indicate how much more advantageous such a condition is than when
the palatal segments approach more nearly the horizontal.
[Illustration: FIGS. 42 AND 43.—Diagrams representing the greater
facility for bringing the muco-periosteal flaps together when the palatal
segments are vertical rather than horizontal. (_Mason._)
A B. Bony palatal segments.
A C. Muco-periosteal flaps.]
My friend Mr. Oakley Coles has in his book on ‘Deformities of the
Mouth’[64] gone very fully into the question of the association of
abnormalities in the shape of the cranium with deformities of the palate,
endeavouring to prove that the palatal defect is concurrent with, if
not dependent upon, a non-development of the left lower parietal region
of the cranium, _i. e._ of the portion of the skull overlying Broca’s
convolution, which governs the function of articulate speech. Into this
question space forbids me to enter here, and I would refer my readers to
his excellent book, merely quoting some of the conclusions at which he
arrives:
“1. There seems a definite relation between palate and cranium; certainly
as to length and breadth, probably as to outlines.
“2. In palatal deformity or interference with the mechanism of speech,
there seems to be in a large number of cases asymmetry of the brain-case.
“3. In strongly marked cases of malformation of the upper or lower jaws,
there is equally well-marked asymmetry of the skull.
“4. In a notable number of cases this flattening of the cranium is on the
left side.
“5. It is generally admitted that the language, speech, and sound centres
are chiefly on the left side of the brain.
“6. Evidence is obtainable that structural defects, mechanical injuries,
or pathological changes involving these parts produce defects of language
and speech.
“7. In so far as functional activity and capacity may be taken as
measures of organic perfection or otherwise, it may be assumed that
certain cases of cleft palate, or the subjects of some other deformities
in the maxillary region, who have also a deficiency in the articulate
sound function are also deficient in the articulate sound nerve-centre.
“8. And as it has been shown that congenital structural defect of the
brain is frequently associated with physical deformity of the skull, so
it may be useful to regard the conformation of the skull as part of the
evidence by which we may estimate the development of the brain.
“9. If it be possible to avail ourselves of the facts that are stated,
and the inferences that are indicated, we may be able to prognose with
a greater degree of certainty the future language and speech capacity
of sufferers from palatal and maxillary deformities of congenital
origin.”[65]
* * * * *
We must now turn to the functional results of these deformities, and
trace out some of the effects which they produce on the economy.
[Illustration: FIG. 44.—Soft metal cover to teat of feeding bottle, which
can be moulded to the infant’s mouth, and act as an obturator during
suction. (_Mason._)]
We necessarily place in the front rank the serious difficulties met with
in the administration of _nutrition_. Where the lip alone is involved,
and that only to a slight degree, but little difficulty arises, as
the child is usually able to suck; but in the severer cases of cleft
lip, involving also the alveolus and palate, the child’s life may be
endangered from the inability to take or to swallow sufficient food. For
as the cleft alveolus and lip seriously impair the power of suction, so
the cleft palate allows the fluid which has found its way into the mouth
to regurgitate through the nose. In many such cases spoon-feeding is
the only chance for the child. To carry this out successfully the head
must be thrown well back, so that the fluid may pass directly into the
pharynx; in fact, the child is often obliged to drink like a bird, in
which, as is well known, the communication between the mouth and nose
through the non-union in the median line of the palate bones necessitates
a similar manœuvre. But even when this precaution is taken, there is no
doubt that many infants with fissured palate die of sheer starvation. Mr.
Mason suggested the use of an apparatus such as that figured below (Fig.
44). It consists of an ordinary india-rubber teat attached to a feeding
bottle. Over the teat is a very thin plate of soft metal, which can be
readily moulded to fit the infant’s mouth, and so act as a temporary
obturator. It may be used with advantage in some cases, but I have not
employed it largely, preferring to trust to careful spoon-feeding. A
similar contrivance in india-rubber which can be fitted to a Maw’s
feeding bottle has been successfully used. A covered spoon with apertures
left at either end is, in the hands of an intelligent nurse, an efficient
contrivance.
Coles has devised an artificial palate attached to a shield to go
over the mother’s breast (Fig. 45) in order to enable the infant to
take its natural nourishment. It is made of thin elastic rubber, is
not uncomfortable, can be kept perfectly clean, and from the shape in
which it is made can be used for either breast. In exceedingly delicate
children the employment of this device may be advisable.
[Illustration: FIG. 45.—Nipple shield suggested by O. Coles for use
in cases of cleft palate. A is the apparatus fitted to the breast,
and prolonged anteriorly so as to form a shield, which projects over
the nipple. When in the child’s mouth it acts as an obturator, partly
shutting off the nasal cavity. (_Coles._)]
In the severer cases it must not be forgotten that it is quite possible
that some other factor is engaged in the production of the rapid wasting
which in spite of every precaution may ensue, such as mesenteric
tuberculosis, or some congenital intestinal or vascular defect. Whether
such exist or not, the child quickly emaciates, the face becomes pinched
and old-looking; the skin has an earthy appearance and hangs in
wrinkles, lax and inelastic; and death, practically from starvation, soon
ends the chapter.
When our patient survives the dangers of infancy and arrives at boyhood
or girlhood, the regurgitation of food through the nostrils ceases,
except under occasional circumstances or in very severe cases; and
although the difficulties of infant nutrition are often manifested
in a much retarded growth, yet there is no reason why the physical
constitution of the patient should ultimately suffer. Again, the
knowledge of such visible and audible defects before operative treatment
has been undertaken has a decidedly depressing influence upon the mind.
The subjects of this deformity, from evident consciousness of their
repulsive aspect, shun the observance of others as they grow older; and
so strong is the sentiment which prevails as to maternal impressions that
they are studiously avoided by women in the earlier stages of pregnancy.
I have often noticed a distressed or hunted expression on the face of
those who had attained to adult life before surgical treatment had been
undertaken; and its disappearance after a successful operation has been
equally marked.
Defective _articulation_ is another serious accompaniment of these
deformities. Although this may be present to a slight degree as a result
of a simple cleft in the lip, yet it is only when the palate is imperfect
that the trouble is obviously manifest. The defect consists in the
inability to articulate distinctly any but the open vowel sounds, and
those few consonants which do not require the nasal cavity to be entirely
shut off from the buccal. For the production of the labials, dentals,
and gutturals, it is essential that there be a complete closure of the
posterior nares; and as the mechanism for effecting this is imperfect,
the production of the sounds must be similarly defective. In spite of
these difficulties, it is extraordinary how adults suffering in this way
can by practice make themselves understood. This inability to completely
shut off the nose from the mouth is undoubtedly the primary cause of the
nasal twang imparted to the voice. Even a small aperture is sufficient
to give rise to a marked defect in speech; whilst cases are recorded
where without any actual cleft the velum from deficient antero-posterior
length could not be approximated to the posterior pharyngeal wall, and a
similar condition of speech has resulted. Indeed, in many instances where
a scanty palate has been successfully sutured, the cacophonic sounds may
for a time persist, though to a less degree than before the operation, a
result either of inability to make this contact through an uncorrected
faulty habit or tension of the velum, or due to the presence of some
small opening. The peculiarity of the twang imparted to the voice varies
according to the amount of communication between the mouth and nose, the
size of the nasal cavities, and the shape of the nostril aperture. Where
the tonsils are enlarged, and adenoid vegetations exist in considerable
numbers on the pharyngeal wall, the size of the communication may be
reduced, and articulation thus rendered more distinct. It is a question,
therefore, whether these growths should be removed unless for some
pressing reason.
Singing is interfered with, though to a much less degree than is ordinary
speech, although the words sung will be indistinct. Whispering, moreover,
is impossible; but most of these conditions will not be very manifest
if the velum alone be fissured. Mason notes that it is very difficult,
and in some cases impossible, for the patients to blow out a candle; and
similarly they cannot perform on wind instruments.
The passage of air into the mouth and over the tongue tends to produce
dryness of the latter organ, and consequently excessive thirst. The
abnormal exposure of the parts to the unwarmed air produces a tendency
to nasal catarrh which is very decided; and, in fact, it is very common
to find a condition of chronic granular pharyngitis present, associated
with adenoid vegetations and chronic enlargement of the tonsils. Patches
or crusts of dried mucus may be observed clinging to the mucous membrane,
and these have occasionally been mistaken for sloughs. From these arises
a peculiar odour, which, however, cannot be quite accurately described as
fœtor. The falling of mucus into the mouth is another unpleasant result,
and the loss of the faculty of smell is in some cases most distinct.
The sense of taste is very defective in all severe cases, from the fact
that the tongue cannot be applied to the palatal surface in such a way
as to bring the food successively in contact with the organs of taste;
moreover, as is well known, the senses of smell and taste are closely
correlated, and where smell is absent, taste is deficient. This was very
well illustrated in one of my cases, where the operation for closure of
a complete cleft was not undertaken until the girl was twenty-five years
of age; it was entirely successful, and she told me subsequently that the
ability to appreciate the tastes of different foods in a way of which she
had no idea previously was not one of the least of the advantages derived
from the operation.