William Rose

“ The name is really a misnomer, in that the condition (as has been many times pointed out, but notably by Fergusson) does not simulate a hare’s lip except in the fact of being cleft, for the natural [3] cleft in the animal’s lip is always in the median line below, bifurcating above to reach either nostril (Fig. 1) , whereas in the abnormal human lip the cleft lies to one or the other side. Instances of median defect are known, but they are extremely uncommon, and consist often of more than a simple fissure. ”

“ The width of the cleft varies as much as the extent, and is a matter of great importance prognostically, as the broader clefts are much more difficult to close. The direction or slope of the segments of the bony palate also differs considerably, in some instances being more or less horizontal and following the normal curve; in others one or both of the segments is much more nearly vertical, a condition which is not at all unsatisfactory, for, as will be explained hereafter, the more horizontal the palatal processes, the more difficult is it to gain satisfactory closure by operation (p. 65) . ”

“ The deformity may exist as a simple notch in the soft tissues of the lip, unilateral (Figs. 2 and 3) or bilateral (Fig. 4) ; when more decided, it may implicate one or both nostrils (Figs. 5, 6, and 7) . In mild cases the alveolus is intact; in others, cleft, constituting the variety known as alveolar harelip, and the line of fissure may, or may not, extend backwards into the palate. In all cases of double alveolar cleft, the palate is also involved, and the central parts of the lip and intermaxilla tend to project forwards ”

“ But the separation of the facial elements is not always maintained; sometimes they fall or are drawn together by the united palate, resulting in the so-called congenital atresia of the nose (“angeborene Atresia der Choanen”) , cases of which have been recorded by Luschka, Bitot and Engel. The latter states that in an infant’s skull examined, only 2 or 3 mm. of space existed between the orbits, and 4 mm. between the optic foramina.
2. True median cleft of the upper lip with development of the intermaxilla is an excessively rare occurrence, but a few cases have been now recorded. ”

“ The usual type of history given is that after the mother has seen the defect in the newly-born infant, she looks back over the preceding nine months to see if there were any apparent cause for the trouble, and seeking out particularly some shock or fright produced by seeing something resembling the defect in her infant often selects something trivial and irrelevant. ”

“ Occasionally one sees in the upper lips of children a congenital red line apparently cicatricial, occupying the position of the normal harelip fissure, and which has been supposed to indicate a natural cure of a temporary defect of development. ”

“ Harelip is a congenital deformity of the upper lip, characterised by a cleft extending for a variable depth, either through the soft tissues of the lip only, or implicating in addition the alveolus, floor of the nose, and palate. ”

“ Incorporated with it are five pairs of muscles, controlling its movements; it is covered by a smooth thin mucous membrane, and terminates posteriorly in the uvula. The arrangement of these muscles is important, not only from their normal physiological functions, but also from their irregular action and effects in cases of cleft palate (Fig. 28) . They may be arranged in groups: two, the levator and tensor palati, form a superior group; the azygos uvulæ is intermediate; and the palato-glossus and palato-pharyngeus form an inferior set. ”

“ The normal shape of the palate is a regular arch, bounded laterally by the gums and alveoli into which the teeth are implanted so as to describe a parabolic curve, being normally uninterrupted at any spot by spaces or diastemata. The height and curvature of the palate vary considerably in different individuals, not only from inherited peculiarities, but also from acquired conditions dependent on the teeth. A person with a good set of sound teeth will probably own a regular well-formed palate ”

“ Harelip—Cleft palate—Frequency—Occurrence in animals—Associated deformities—Median harelip—Facial clefts—Macrostoma—Mandibular clefts—Causes of these deformities.
The congenital fissures and deformities of the mouth and lips form a group which is considerably larger than might be imagined from the scanty notice given them in ordinary text-books; and although many are extremely rare, yet possibly if more attention were drawn to them, fresh cases would be noted and recorded, and the somewhat scanty materials from which we have to work out their development and characteristics would be increased. ”

“ In the median line is a well-marked raphe, extending anteriorly to a prominence indicating the position of the anterior palatine canal. The rugose condition of the membrane over the hard palate is not seen in young children; it supervenes later in life. ”

“ Into its formation several bones enter; in the adult skull one usually sees posteriorly a cruciform suture indicating the limits of the superior maxillæ and palate bones; but even in the adult, evidence is forthcoming in the existence of traces of sutures to indicate that the anterior part of the palate is formed independently of the part immediately behind it. ”

“ The shape of the nose in unilateral harelip is very characteristic, [4] being broad and flattened out from the deficiency of the floor and posterior wall of the anterior nares.
Figs. 7 and 8.—Double harelip with projection of the os incisivum, as seen from the front and in profile. (Fergusson.)
Harelip seems to occur more commonly in boys than in girls. According to Müller, out of 270 cases, 170 were boys, and 100 girls.
Unilateral harelip is more commonly met with on the left side than on the right; probably 60-70 per cent. of the cases are left-sided. ”

“ Arising from the extremity of the petrous bone, the levator passes downwards, and spreading out below unites with its fellow in the whole length of the median raphe. The tensor arises from the navicular fossa of the internal pterygoid plate, and after being reflected around [29] the hamular process, its action there being assisted by the interposition of a bursa, is attached to the anterior portion of the aponeurosis and to the hinder part of the bony palate. ”

“ Other associated malformations are on record, e. g. an extra thumb on each hand; and Sir Morell Mackenzie has reported a case in which there was a congenital fissure between the arytænoid cartilages with a trilobate epiglottis, occurring in conjunction with harelip and cleft palate. [12]
The remaining deformities to be noticed here are much less common, but demand attention by their rarity and interest, and on account of the light they throw on the embryology of the lip and mouth. ”

“ As with harelip, so with cleft palate, the extent of the defect varies greatly in different cases. Thus in the most severe forms, there is a total mesial longitudinal cleft, [6] extending forwards from the tip of the uvula to the level of the anterior palatine canal, thence bifurcating to communicate anteriorly with a double alveolar harelip, the os incisivum or central portions of the intermaxilla being usually displaced forward (Fig. 9) . ”

“ In some instances the deformity dies out of families, possibly from the fact that the defective condition in one parent is remedied by a more perfect development in the [24] other; whilst in others the tendency distinctly increases, and a father or a mother with harelip will beget a family where three out of the four or five children will be similarly affected. By a proper selection of mates this deformity could probably be bred out, as well as bred up to. ”

“ The combined action of these muscles raises and makes tense the velum, and in addition influences the Eustachian tube; but the levator is by far the more important. The azygoi uvulæ muscles arising from the median raphe and spine of the hard palate descend to the tip of that process, and are thus able to regulate its length.
Fig. 28.—Muscles of palate dissected. The cut represents the posterior nares and upper surface of the soft palate.
a. The levator palati. b. The inner bundle of fibres of the palato-pharyngeus, forming the posterior pillar of the fauces, c. The palato-glossus. d. ”

“ Its increase in length is from 20 to 30 millimetres, whilst its breadth is only augmented by 10 to 15 mm., and this mainly posteriorly. When once the permanent incisors, canines, and premolars are developed, the anterior portion of the palate alters but little in shape, unless any of these teeth be lost, and the gaps not artificially maintained.
Dr. Ehrmann [36] states that the alveolar border in front of the canine teeth forms a nearly regular semicircle, with a posterior transverse diameter of 22-26 mm.; thence the alveoli diverge regularly, adding to the diameter about 2-4 mm. ”

“ In addition to this the eyes were affected with coloboma, the right eye presenting other serious defects. “On examining the child before its death,” the author states, “I felt convinced that there was no ethmo-vomerine plate, and this conviction was strengthened by the peculiar shape of its forehead. ”

“ This deformity may be unilateral or bilateral (Guersant, Meckel) , more frequently the former; and is not uncommonly associated with macrostoma of the same or opposite side of the face (Guersant, Pelvet [18] ) , as seen in Fig. 20.
Albrecht [19] records a most interesting case in a newly born pup (Fig. 21) of double clefts extending from the lip margin upwards not only into the nostril, but also towards the eye on either side, i. e. a double associated harelip and facial cleft. The specimen is taken from the Royal Veterinary College of Brussels.
[18]
Fig. ”

“ The accompanying illustrations well indicate this arrangement of sutures and teeth (Figs. 26 and 27) ; the importance of these facts will be emphasized later. All traces of the facial aspect of these sutures disappear quite early in life.
Figs. 26 and 27.—Diagrams to represent the normal human upper jaw of a child, with four and six incisors respectively, and also indicating the five intermaxillary sutures. (After Albrecht.)
EG, MG, XG. Endo-, meso-, and exo-gnathion. e. Inter-endognathic suture. f. Endo-mesognathic suture. g. Exo-mesognathic suture. i1. Central incisor. i2. Lateral incisor. ”