Assistant Chief, Plastic Surgery Service, Department of Surgery, Walter Reed General Hospital, Walter Reed Army Medical Center, Washington D.C.

Transcription

1 RESTORATION OF ORBICULARIS ORIS MUSCLE CONTINUITY IN THE REPAIR OF BILATERAL CLEFT LIP By MICHAEL M. DuFFY, Lt.-Colonel, M.C., U.S.A., Washington D.C. Assistant Chief, Plastic Surgery Service, Department of Surgery, Walter Reed General Hospital, Walter Reed Army Medical Center, Washington D.C. THE repair of bilateral cleft lip requires the reconstruction of discrete anatomical structures. A major omission has been the failure to restore completely continuity of the orbicularis oris muscle. A means of achieving this, while simultaneously exploiting the better features of conventional repair, is here presented.?, FIG. I Without continuity of muscle, a pucker is impossible. Discontinuous muscle wads up laterally. A smile stretches and thins the central segment. Functional and Cosmetic Deficit.--The orbicularis oris muscle is not a simple sphincter muscle ; it is also an important muscle of facial expression. Much of this function in the upper lip is dependent upon five other facial muscles (the triangularis, the buccinator, the incisivus superior, the levator anguli otis, and the depressor septi nasi) all of which either cross the midline or contribute slips which insert into the orbicularis otis near the midline. Failure to restore midline continuity results in altered function, by changing their mechanical advantages through mislocating their attachments. Without continuity of muscle, a pucker is impossible and a smile becomes an elevation of the corner of the mouth rather than a gentle upward sweep across the upper lip (Fig. I). 48

2 RESTORATION OF ORBICULARIS ORIS MUSCLE 49 Anatomy and 51orphogenesis of the Orbicularis Oris Muscie.--The prolabium in bilateral complete cleft lip contains no anatomically or functionally sigllificant muscle (Lee, 1946). The muscle fibres of the lateral cleft margin sweep upward toward the nasal floor. As they approach the cleft margin the fibres become fewer in number and attenuated. Their definition is lost and they become enmeshed in a fibrous band beneath the cleft mucosa paralleling the cleft margin (Fara et al., 1965). The exact origin of the subphiltral portion of the orbicularis oris muscle is obscure. Based upon the theory of mesodermal penetration (Stark, 1954 ; Stark and Ehrmann, I958), an interesting hypothesis emerges. In bilateral cleft lip an apparently normal central mesodermal mass exists : it is the relative deficiency of the lateral mesodermal masses which allows ectodermal dehiscence and cleft formation between the fifth and seventh wcek of gestation. In the normal lip this mesoderrn begins differentiation into rhabdomyeloblasts as early as the seventh week, as evidenced by cellular elongation, formation of condensed cell groups with their long axes parallel, mitotic proliferation, and development of cross-striated fibrils (Hewer, 1928). Muscle from cleft lips, other than at the cleft margin, is histologically indistinguishable from that of non-cleft lips (Lee, 1946 ; Fara et al., 1965) in newborns and may be considered as the end result of the same developmental process. If the mesoderm in the deficient lateral labial masses can evolve into normal muscle, why is it that the normal central mesodermal mass fails to form muscle in the prolabium? This mesoderm is derived from the second branchial arch as evidenced by its seventh nerve innervation. It would at first seem tenable that the cleft might mechanically obstruct innervation of the prolabial area. This, however, does not explain the failure to differentiate into striated muscle. Motor end plates do not appear in this area until 2o weeks of gestation, by which time muscle fibres are well defined (Hewer, 1935). Other evidence that muscle morphogenesis is in no way dependent upon innervation has been supplied experimentally in that the frog embryo, rendered nerveless by extirpation of the spinal cord, develops normal muscle fibres (Harrison, 19o4). The possibility that these fibres do form, but disappear prior to birth because of non-innervation, is refuted by thc observation that normal muscle exists in the leg and foot of the human newborn despite the fact that motor end plate formation is not yet completed (Hewer, 1935). This evidence suggests that the medial mesodermal mass differs from the lateral masses in that it is incapable of differentiating into striated muscle. If this is the case, the subfiltral segment of the orbicularis oris muscle of the upper lip is formed entircly from migratory ingrowth of rhabdomyeloblastic tissue originating from only the lateral mesodermal masses. The completed muscle derives its seventh nerve innervation solely from the lateral area. Muscle continuity is complete and capable of contraction by the ninth week, as evidenced by the response to stimulation in viable human embryos obtained at hysterectomy (Langworthy, I933), despite the fact that motor nerve endings are not yet demonstrable. This hypothesis is supported by other observers who describe sparse bundles of muscle traversing a Simonart's band and then fanning out into the prolabium as if thwarted in their attempt to migrate into the prolabium (Fara and Smahel, 1967). These same authors describe muscular budding and invasion into prolabial tissue for several millimetres following repair of the cleft. This, however, seems to be of little functional consequence either in regard to electromyographic evidence (Rees et al., 1962) or functional deficiencies readily apparent in many repaired lips. Previous Approaches.--The majority of generally accepted bilateral cleft tip repairs such as curved incisions (Veau, 1922), triangular flaps (Brown et al., 1947 ; ID

3 ~O BRITISH JOURNAL OF PLASTIC SURGERY Marcks eta[., 1957 ; Bauer et al, 1959 ; Skoog, I965), and rotation-advancement (Millard, I~6oa, b), simply ignore the subphikral muscle deficit. The muscle of the lateral side is sewn to the incised prolabial margin which resuks in stretching of the skin and an unnaturally broad central lip. This defect can be minimised by anchoring the muscle to the premaxillary periosteum ;howevcr, this still fails to restore functional muscle continuity of the central lip. Other repairs based upon the quadrangular flap (Barsky, 195o ; Stenstrom, 1957) partially restore continuity of the muscle by joining it in the lower third of the lip. These repairs do not produce the best results as their design does not conserve muscle present in the lateral segment ; too tight an upper lip often results. The U-shaped scar in the upper lip produces secondary deformity, and the sacrifice of the white line and prolabial vermilion results in destruction of the cupid's bow and lack of vermilion fullness. The central muscle deficit has been approached by the use of a primary cross-lip flap (Clarkson, 1954). This is an intriguing approach with some theoretical advantage, but aside from the technical risks to the infant, much of the valuable tissue of the prolabium is sacrificed and an additional secondary defect is produced. Another interesting approach has been the lifting of the prolabial skin on a columellar pedicle to allow complete lining of the back of the prolabium with the lateral cleft mucosal edge to produce a sulcus (Bauer er al., 1959 ; Tondra et al., 1966). There is partial restoration of muscle continuity by virtue of the fibrous attachment of the muscle to the unrolled mucosa, but no effort is made actually to mobilise the muscle and advance it until it can be joined to itself in the midline as a discrete layer in the closure. Repairs have been reported which do reconstitute the whole muscle. The cleft margin of the lateral elements has been pared back to muscle and sutured beneath a prolabial flap (Glover and Newcornb, 1961). The general result has been to produce too tight a lip with excessive vertical height. Others have used cheek flaps (Gabano, 1967) similar to those used in the reconstruction of upper-lip defects, with the shortcomings of negligence in tissue conservation and excessive scarring. More Satisfactory Bilateral Cleft Lip Repair.--In bilateral cleft lip skin, white line and vermilion are present in the prolabium, though often hypoplastic (Fig. 2). It is a logical goal to utilise the whole height of the prolabium and preserve these structures in order to produce a normal philtrum, cupid's bow, and suctorial pad. They are capable of expansion in response to muscular pull. It can be seen by simple vector analysis that union of the orbicularis oris muscle behind a central segment of prolabium can act to assist the surgeon in his efforts (Fig. 3). To accomplish this, curved incisions are made from the base of the columella to the cupid's bow peak on each side, preserving at the top a pedicle for circulation the width of the columellar base. This philtral segment of skin is then undermined throughout its attachment to the prolabium, leaving the vermilion also attached at its lower border. This forms a prolabial tunnel through which the lateral muscle may be joined (Fig. 4). Muscle.--The muscle of the lateral cleft dement can be directly sutured through the prolabial tunnel without such tension as to cause dehiscence. To accomplish this the lateral cleft margin is superficially denuded of epithelium only. The attentuated muscle and its condensation of connective tissue is preserved. This fibrous border is uniquely suited to retain sutures against the ensuing muscle pull. The skin is then undermined for about 5 mm. freeing the muscle so that it can be drawn medially for an additional 2 ram. on each side. Sutures may then be passed through the fibrous muscle margins, traversing the prolabial tunnel, and tied, uniting the muscle in the midline within the tunnel.

4 RESTORATION OF ORBICULARIS ORIS MUSCLE 51 Columella.--The col,jmella, as well as the prolabium, may be hypoplastic. In addition, the downward pull of the intact muscle may steal from what columella is present. The skin flaps at the lateral edges of the prolabium, as used in the forked flap A G D E F 6 H FIG. 2 A, Dotted lines indicate skin incisions. B, The incision is made full thickness in the prolabium and beneath the ala : only the cleft mucosa is stripped from the lateral cleft margin exposing the fibrous band. C, Horizontal section of lateral cleft margin dissection. Cleft mucosa only is discarded and the skin undermined for 5 mm. allowing advancement of muscle. D, The prolabial tunnel is created. E, The fibrous bands at the muscle edges are sutured to each other through the prolabial.tunnel. F, The remaining incisions are sutured. Note that the lateral prolabial flaps are not trimmed to fit. Excess tissue is "banked" in the nasal floor. G, Dotted lines indicate incisions for later columellar lengthening. Stippled area indicates extent of undermining. H, Completed closure. Muscle pull has elongated lip segment. (Millard, I958), provided a source of tissue for columella. They cannot, at this operation, be advanced into the columella as this would interrupt circulation to the central prolabium. This may, however, be rotated up into the nasal floor. This produces an excess which is allowed to remain despite the deformity produced in the nasal floor. This tissue is essentially " put in the bank" for later use in columellar lengthening from the nasal floor (Cronin, I958). Prolabial Sulcus.--Lateral lip mucosa can be carried through the prolabial tunnel with muscle. This is trapped by the attachment of the vermilion to the premaxilla at the lower border of the prolabial tunnel. This attachment awaits division at a later time as it serves to tether the lip to the premaxilla during the time the muscle is active in repositioning it.

5 REPAIR WITHOUT MUSCLE CONTINUITY I. Transverse vectors widen protabium. 2, Vertical vectors oct laterally to enhance central notch, REPAIR WITH MUSCLE CONTINUITY m. Tronsvers~ vectors cancel eachother and do not oct to wldon prolablum. 2. Vertical vector is doubled andocts controlly to ~longote proloblum, FIG. 3 Diagrammatic representation of simple vector analysis comparing the effects of repaired and unrepaired orbicularis muscle.

6 RESTORATION OF ORBICULARIS ORIS MUSCLE 53 The Prernaxilla.--Surgical setback of the premaxilla is not necessary or desirable for reconstimtion of the orbicularis oris muscle. The muscle will reach, and once united is a potent force in repositioning the premaxilla. A removable splint is desirable to prevent collapse of the lateral maxillary segments behind the premaxilla. If a space is retained into which the premaxilla can settle, the intact muscle will generally retroposition it. PRELIMINARY CASE REPORTS Case I.--This patient (Fig. 5) was born with a severe bilateral cleft lip and palate. At the age of 3 months the lip was repaired in one stage, uniting the orbicularis oris muscle through a 4~ Case I. FIG. 5 Pre-operative appearance. prolabial tunnel. Prolabial tissue, unused in the lip repair, was " banked " by rotating the excess into the nasal floor (Fig. 6). At the age 18 months the palate was repaired and at age 3 years a columellar lengthening was carried out utilising the excess tissue stored in the nasal floor (Fig. 7). The muscle in the prolabial tunnel was biopsied at this time and reported as normal skeletal muscle. Repositioning of the premaxilla is incomplete because of failure to maintain space immediately following lip repair. Maxillary orthopaedic therapy with a removable appliance is currently under way. Case z.--this patient (Fig. 8) was born with a bilateral incomplete cleft iip and cleft alveolus without cleft palate. At age 3 months.the lip was repaired at one stage uniting the orbicularis muscle through a prolabial tunnel (Fig. 9)- If the hypothesis is tenable that the lateral cleft segments contain the muscular elements for the entire upper lip, the next logical step is to test it. A repair has been devised to extend the usefulness of techniques described by many outstanding surgeons. The cases shown are early and must await significant evaluation in terms of final function and appearance. It is hoped that the feasibility of restoring muscle continuity will be considered by those who repair bilateral cleft lips.

7 FIG. 6 Case 1. Following lip repair with restoration of muscle continuity. U n u s e d prolabial tissue has been " banked " in the nasal floor. Case z. FZG. 7 Following columellar lengthening using " banked " t i s s l l e from th~,~q,! on,~

8 RESTORATION OF ORBICULARIS ORIS MUSCLE 55 FIG. 8 FIG. 9 Fig. 8.--Case 2. Pre-operative appearance. Fig. 9.--Case 2. Following lip repair with restoration of muscle continuity. Tissue has not been " banked " in this case as the nasal deformity was minimal and columellar lengthening is not anticipated. SUMMARY I. The cosmetic and functional defect of failure to restore continuity of the orbicularis oris muscle is re-emphasised. 2. The anatomy and morphogenesis of this muscle are reviewed. 3. It is suggested that the subphikral muscle has its origin entirely from the lateral cleft segments. 4. A means of restoring continuity to this muscle is presented with the early results in two patients. REFERENCES BARSKY, A. J. (195o). " Principles and Practice of Plastic Surgery." Baltimore : Williams & Wilkins. BAUER, T. B., TRUSLER, H. M. and TONDRA, J. M. (1959). Changing concepts in the management of bilateral cleft lip deformities. Plastic and Reconstructive Surgery, 24, BERKELEY, W. T. (I96I). The concepts of unilateral repair applied to bilateral clefts of lip and nose. Plastic and Reconstructive Surgery, 27, 5o BROWN, D. (1949). Harelip. Annals of the Royal College of Surgeons, 5, BROWN, J. B., McDOWELL, F. and BYARS, L. T. (1947). Double clefts of the lip. Surgery Gynecology and Obstetrics, 85, 2o-29. CLARKSON, P. (1954). Use of the Abbe flap in the primary repair of double cleft lip. British ffournal of Plastic Surgery, 7, CRONIN, T. D. (195.7)- Surgery of the double cleft lip and protruding premaxilla. Plastic and Reconstruetzve Surgery, I9, 389-4oo." CRONIN, T. D. (1958). Lengthening columella by useof skin from nasal floor and alto. Plastic and Reconstructive Surgery, 21, FARA, M., CHLUMSKA, A. and HRIVNAKOVA, J. (1965). Musculus orbicularis oris in incomplete harelip. Acta chirurgice plasticce, 7, FARA, M. and SMAHEL, J. (1967). Postoperative follow-up of restitution procedures in the orbicularis oris muscle after operation for complete bilateral cleft of the lip. Plastic and Reconstructive Surgery, 40, GABANO, P. (1967). Some technical points about the repair of doable cleft lip. ehirurgice plasticce, 9, o. Acta

9 56 BRITISH JOURNAL OF PLASTIC SURGERY GLOVER, 1). M. and NEWCOMB, M. R. (1961). Bilateral cleft lip repair and the floating premax:fla. Plastic and Reconstructive Surgery, 28, HARRISON, R. G. (1904)- An experimental study of the relations of the nervous system to the developing musculature in the embryo of the frog. American Journal of Anatomy, 3, o. HEWER, E. E. (1928). The development of muscle in the human foetus. Journal of Anatomy, 62, HEWER, E. E. (1935)- The development of nerve endings in the human foetus. Journal of Anatomy, 69, LANGWORTHY, O. R. (1933). Development of behaviour patterns and myelinization of the nervous system in the human foetus and infant. Contributions to Embryology, i39, LEE, F. C. (1946). Orbicularis otis muscle in double harelip. Archives of Surgery, 53, MARCKS, K. M., TREVASKIS, A. E. and PAYNE, M. J. (1957). Bilateral cleft lip repair. Plastic and Reconstructive Surgery, I9, 4Ol-4O8. MILLARD, D. R. Jr. (1958). Columella lengthening by a forked flap. Plastic and Reconstructive Surgery, 22, MILLARD~ D. R. Jr. (I96oa). Adaptation of the rotation-advancement principle in bilateral cleft lip. Trans. int. Soe. plast. Surg., 2nd Congr. 1959, pp Edinburgh: Livingstone. MILLARD~ D. R. Jr. (I96Ob). A primary compromise for bilateral cleft lip. Surgery Gynecology and Obstetrics, III, MILLARD, D. R. Jr. (1968). Double cleft lip. In " Plastic Surgery ", ed. Grabb, W. E. and Smith, J. W. Boston : Little Brown. REES, T. D., SWINYARO, C. A. and CONVERSE, J. M. (1962). The prolabium in the bilateral cleft lip. Plastic and Reconstructive Surgery, 3, SKOOG, T. (1965). The management of the bilateral cleft of the primary palate (lip and alveolus). Plastic and Reconstructive Surgery, 35, STARK, R. B. (1954)- The pathogenesis of harelip and cleft palate. Plastic and Reconstructive Surgery, 13, STARK, R. B. and Em~/~Alqlq, N. A. (1958). The development of the center of the face with particular reference to surgical correction of bilateral cleft lip. Plastic and Reconstructive Surgery, 2I, STENSTROM, S. (1957). The " quadrilateral flap " operation applied in primary and secondary one-stage repair of bilateral cleft harehps. Plastic and Reconstructive Surgery, I9, TONDRA, J. M., BAUER, T. B. and TRUSLER, H. M. (1966). The management of the bilateral cleft lip deformity. Acta chirurgi~e plasticce, 8, VEAU, V. (1922). Operative treatment of complete double harelip. Annals of Surgery, 76,