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Home , Bone, Maxilla, Process (anatomy), Zygomatic arch, Zygomatic bone, Zygomatic process

FRACTURES OF THE ZYGOMATIC COMPLEX

RUSSELL HOPKINS M.R.C.S., L.R.C.P., B.D.S., F.D.S.R.C.S. Consultant in Oral , University Hospital of Wales, Cardiff THE FRONTAL of the zygomatic articulates superiorly with the at the zygomatico-frontal , giving attachment on its orbital aspect to the suspensory of the eye (Lockwood's) at the lateral orbital (Whitnall's). Posteriorly the of the articulates with the zygomatic process of SUBCONJUNCTIVAL HAEMORRHAGE

Fig. 1. A diagrammatic representation of the anatomical basis of the common signs and symptoms of fracture of the zygomatic complex. Minor occlusal disturbance occurs if there is an associated alveolar fracture. the to form the . The temporal is inserted into the upper aspect of the arch and deep to it lies the temporalis muscle attached to the coronoid process of the . Antero-inferiorly the bone articulates with the zygomatic process of the forming the lateral two-thirds of the inferior orbital margin and enclosing the infra-orbital . In the articulating with the greater wing of sphenoid above and the maxilla below, the bone forms part of the lateral boundary of the . The zygo- matic bone forms the superior antero-lateral boundary of the maxillary antrum and, being part of the orbital , affords considerable protection to the eye. Postgraduate Lecture (Ann. Roy. Coll. Surg. Engl. 1971, vol. 49) 403 RUSSELL HOPKINS The area is referred to in this paper as the 'zygomatic complex' but the 'malar' or 'lateral middle third' is also used. SIGNS AND SYMPTOMS OF FRACTURE OF THE ZYGOMATIC COMPLEX The signs and symptoms arising from its fracture are referable to the anatomy (Fig. 1). Epistaxis and sub-conjunctival haemorrhage. If the complex is the sole facial fracture, epistaxis 'is unilateral; initially fresh, it later becomes

k~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~...... Fig. 2. Demonstrates a sub- Fig. 3. Demonstrates the resi- conjunctival haemorrhage and dual deformity of an untreated the associated peri-orbital ecchy- fracture with loss of mosis of a patient with a prominence, enophthalmos, loss fracture of the zygomatic of vision, downward displace- complex. ment of the pupil and of the lateral aspect of the , with a pseudo-ptosis. a posterior nasal discharge persisting for several days as the blood clot is removed from the maxillary antrum. A sub-conjunctival haemorrhage, without a posterior margin, is indicative of a fracture of the orbital skeleton and/or the anterior . There is generally an asso- ciated peri-orbital ecchymosis. (Fig. 2). Anaesthesia. Damage to the infra-orbital nerve as it passes for- wards in its groove and canal affects the sensory supply of the lower , cheek, upper and side of the nose. The upper and canine teeth and adjacent gingival supplied by the anterior superior dental nerve may be similarly affected. Anaesthesia of the 404 FRACTURES OF THE ZYGOMATIC COMPLEX occurs when the frontal nerve is compressed in the (vide infra). Diplopia. This results from distortion of the orbital and is due to: (a) Intra-orbital oedema, haemorrhage and muscle spasm. (b) Distortion of the suspensory ligament of the eye and lowering of the pupil level in injuries where the fracture line passes above the lateral orbital tubercle. (c) Prolapse of orbital contents through the severely comminuted orbital floor into the antrum. (d) Trapping of the inferior oblique and/or in the fractured orbital floor. (c) Ophthalmoplegia occurring as a result of nerve damage within the orbit, superior orbital fissure, or posteriorly with a concomitant fractured . Diplopia may not occur, even though there is enophthalmos, if the fracture is either below the lateral orbital tubercle or after reduction of the fractured lateral orbital skeleton. It is wise to examine the eye for internal damage and, if convenient, to obtain an orthoptic report if diplopia is present as a guide to its subsequent improvement. Enophthalmos. Initially this may be masked by peri-orbital ecchy- mosis and oedema. It results from: (a) Prolapse of the orbital , fascia and muscle into the antrum. (b) Posterior displacement of the eye due to the backward pull of the recti following the loss of the supporting orbital fat, and/or of the extra-ocular muscles, secondary to their being trapped in the fracture lines. (c) Enlargement and distortion of the orbital cavity associated with displacement of the supporting . (d) Fat necrosis following intra-orbital haematoma. Enophthalmos produces a pseudo-ptosis of the upper eyelid, loss of the supra-tarsal creases and narrowing and downward displacemen,t of the lateral aspect of the palpebral fissure (Fig. 3). . Trismus and limitation of lateral movement of the man- dible may result from the inward displacement of the zygomatic arch and its interference with the coronoid process of the mandible and the . Pain and swelling. As there is no mobility, severe pain is not nor- mally a feature of this injury though the patient will complain of discomfort associated with the fracture and associated bruising. Occa- sionally compression of the infra-orbital nerve will produce a neuralgia which is relieved by the reduction of the fracture. The amount of swelling is variable, but it may be minimal if the 405 RUSSELL HOPKINS case is seen immediately or after a week has elapsed, particularly if the orbit has been enlarged. Flattening of the cheek prominence or depression of the zygomatic arch may then be obvious. As both may be masked by oedema the patient should always be examined from above and behind with the facial tissues stretched downward by the examining fingers. Step deformities of the bony margins should be

Fig. 4. Demonstrates a typical occipito-mental radiograph of a fracture of the right zygomatic complex. sought by palpation, an/d ithe position of the and lids relative to the supra-orbital ridges should be compared as an assessment of enopthalmos. Ecchymosis may be seen and bony be palpable in the buccal sulcus. Surgical emphysema is occasionally demonstrable in the peri-orbital and cheek tissue. During the first pre- and post-operative weeks patients with this injury should be advised to wipe rather than blow their noses. Both 150 and 300 tilted occipito-mental views are essential. A submento-vertical view demonstrates the zygomatic arch, but is not 406 FRACTURES OF THE ZYGOMATIC COMPLEX essential as this area is easily examined clinically and is well demon- strated on the occipito-mental films. The relative positions of both coronoid processes and zygomatic arches should be compared. On comparison with the unaffected side, the involved maxillary antrum will appear radio-opaque due to extravasated blood. Its dimensions will be reduced. The dimensions of the zygomatic bone, however, may appear to be increased, following its rotation and inward displacement. Areas of increased radio-opacity beneath the antral roof may be indicative of a 'blow out' fracture. This is known as the 'hanging drop' effect (vide infra). Separation of the zygomatico-, infra-orbital margin, lateral wall of antrum and zygomatic arch should be noted and the degree of angulation and displacement of the complex assessed so that the subsequent operation may be facilitated (Fig. 4). Surgical emphy- sema may be seen as scattered areas of radiolucency in the . SURGICAL TREATMENT Fractures with minimal clinical and radiographic signs do not require surgical intervention; when there is doubt it is better to re-assess the patient a week later. The anaesthesia of the cheek will usually disappear within several weeks. Unless there is associated soft tissue damage or marked diplopia there is no immediate urgency for treatment in fractures with severe peri-orbital ecchymosis. A delay of up to a week will allow the extravasated fluids to be resorbed, simplifying the operation and re- ducing the risk of dangerous elevation of intra-orbital pressure follow- ing surgery. Figure 5 demonstrates the commonly used surgical techniques. Elevation is usually achieved by means of a temporal approach described by Gillies. The intra-oral technique is undoubtedly quicker, but carries a greater risk of infection, and there are problems of limited access and the angulation of the elevator which is inserted posterior to the malar buttress. The technique is particularly suitable for local fractures of the zygomatic arch. The temporal approach. Most operators shave the temporal hair pre-operatively, causing some temporary embarrassment to the patient. The author thoroughly cleanses the area with cetrimide and, after applying a sterile petroleum jelly, the hair is parted in the area chosen for incision. The adjacent hair is removed and the rest is covered by the drape. No infection has resulted from this technique. With a distracting pressure on either side, a horizontal 2 cm. long incision is made within the hairline of the , between the anterior and posterior branches of the superficial temporal , approximately at the level of the tip of the pinna. The incision is deepened to expose the thick bluish-white which must not be confused with its covering of several thinner layers of 407 RUSSELL HOPKINS . Once haemostasis is achieved the fascia is carefully incised, exposing but not damaging the temporal muscle. A Howarth's nasal raspatory or similar instrument is passed bevel upwards below the lower edge of the fascia to below and behind the zygomatic buttress. In a severely depressed fracture this may require some manipulation. The raspatory is then replaced by an elevator. As it is possible to penetrate the temporal muscle and to place the elevator deep to the

TRANSOSSEUS WIRES

ORBITAL FLOOR INPLANT TEMPORAL FASSCIA _ ANTRAL PACK

Fig. 5. A diagrammatic representation of the commonly used techniques for repairing zygomatic complex fractures. coronoid process, the tip of the elevator should remain in contact with the inner surface of the fascia and then the arch. The required direction and angulation of elevation is predetermined from the radiograph. As a blow of considerable force fractured and displaced the com- plex, a similar controlled force may be required to disimpact and elevate it. The patient's should be held firmly by the assistant. Techniques applying force to the thin temporal bone should be avoided. It is advisable to over-reduce allowing the fractures to interdigitate and be self-retaining. The disappearance of the infra-orbital step, re-appearance of the cheek prominence and zygomatic arch, which is ironed outwards from within, are guides to the correct reduction (Fig. 6a and b). Full reduction is of importance when the arch alone is fractured for the interdigitation of the three fracture lines and two separate fragments make this difficult to achieve. The wound is closed either in layers, or by interrupted sutures inserted through the and temporal fascia. Post-operatively the patient must be prevented from lying on the affected side and as a result peri-orbital ecchymosis may be found on the unaffected side. Several differing elevators are in common use. Rowe's elevator is to be recommended as possible leverage against the temporal bone is avoided, yet the accurate application of considerable force is possible'. The unstable fracture Straight elevation suffices for the majority of fractures. Comminution 408 FRACTURES OF THE ZYGOMATIC COMPLEX may be such that the area collapses once the elevator is removed. Several differing techniques are available in this circumstance. Intraosseous wiring. A significant zygomatico-frontal diathesis is reduced following a direct approach through the unshaven . (An extension of this incision allows access to the supra-orbital ridge when this also requires manipulation.) After the fragments have been

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Fig. 6 (a) and (b). Demonstrates the pre- and post-operative 30° occipito- mental radiographs of a fracture of ,'thes_e right zygomatic complex, treated ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~...... alone...... by elevation reduced they are fixed by means of 0.35 mm. stainless steel wire inserted through burr holes. Occasionally other areas of the orbital skeleton, for example the inferior orbital margin, require similar procedures. In this case figure-of-eight or horizontal mattress wires are advisable to 409 RUSSELL HOPKINS prevent the downward displacement of the zygomatic complex (Fig. 7a and b).

(a) (b)

(c)

Fig. 7 (a) and (b). The pre- and post-operative radiographs of an impure blow-out fracture demonstrating intra-osseous wiring of the fronto- zygomatic suture and infra-orbital margin. (c) Shows the final post-operative appearance of the patient who had an additional Silastic implant of the orbital floor, through a lower eyelid approach. The antral pack. This provides support for the comminuted com- plex from below. After elevation of the fragments an incision is made 410 FRACTURES OF THE ZYGOMATIC COMPLEX near the mucogingival reflection in the buccal sulcus anterior to the malar buttress. Entry into the antrum is made by removing some of the fractured lateral wall at a higher plane than the incision; this prevents a permanent oro-antral fistula.

Fig. 8. Demonstrates the uses of an antral pack in a comminuted unstable fracture of the right zygomatic complex. With continuous lift from the elevator the antral roof and inferior orbital margin are smoothed from below by the exploring finger tip. Any prolapsed orbital contents are carefully returned to the orbit. A gauze strip pack of Whitehead's varnish is inserted in layers supporting the roof of the antrum and its lateral wall by virtue of the triangular cross-section of the antrum. The pack is prepared by soaking the gauze in Whitehead's varnish and drying it under pressure to remove any excess. The end of the pack may be left in the buccal sulcus if required while the pack is retained for approximately two weeks, normally being removed without an anaesthetic. The pack may be contained in a Polythene bag preventing difficulty in removing it caused by bone frag- ments (Fig. 8). Various inflatable devices have been described replacing the antral pack, but they are little used in this country. External pin fixation attached to a head cap or 'halo', or trans-facial Kirschner wires are used in some centres instead of packs or intra-osseous wiring. The blow-out fracture In almost every zygomatic complex fracture the orbital floor is involved. In the majority of cases the peri-orbital and fascia are not perforated and the orbital contents do not herniate into the antrum. An injury has been described where the soft tissue contents 411 RUSSELL HOPKINS of the orbit are driven through the paper-thin orbital floor without the main orbital skeleton fracturing2. This injury is now known as the 'pure blow-out', and an injury fracturing the main orbital skeleton and adjacent facial , associated with the propulsion of orbital contents into the antrum, is called an 'impure blow-out'3. Both injuries may result in enophthalmos, oculo-rotatory disturbance, and infra-orbital anaesthesia. The frequency with which orbital floor damage is found suggests that in the extensively comminuted fracture it is wise to assume that some degree of blow-out has occurred4' '. The diagnosis of the pure 'blow-out' is more difficult, particularly in the early case where blood in the antrum will mask the 'hanging drop' effect seen in the occipito-mental films. Tomography is usually required. Treatment of a 'blow-out' is preferably by infra-orbital exploration, particularly if there is traction evidence of trapping of the inferior rectus or . The traction test consists of anaesthe- tizing the of the lower fornix and grasping the inferior rectus muscle with toothed forceps. If upward rotation of the eye is impaired, muscle trapping may be assumed. It is wise to carry out the infra-orbital exploration within two weeks of the injury, before fibrosis of the muscle becomes permanent. The orbital floor exploration. An incision is made in a skin crease of the lower eyelid. This leaves an invisible and prevents the lymphoedema which occurs if the incision is made at the lower border of the orbit. Blunt dissection deep to the thin mobile skin should expose but not perforate the septum orbitale down to the level of the orbital floor. The overlying orbicularis oculi is split horizontally and the periosteum of the inferior orbital ridge is incised. The orbital floor is easily demonstrated, though posteriorly there may be some limitation of access due to an attached infra-orbital nerve. Damage to the optic nerve which lies above the orbital floor is unlikely. After any necessary reduction of the infra-orbital fractures the prolapsed orbital contents should be carefully withdrawn from the antrum and any free bony spicules removed. The bony defect may be covered by Silastic, Teflon, Polythene or by autogenous bone obtained from a split or ; autogenous bone requires an additional operation, however. The implant supported by sound bone on both medial and lateral sides should be retained by the sutured periosteum. Initially the pupil level may be raised, but as the oedema subsides this normally corrects itself. The author, who uses a Silastic sheeting 0.62 mm. thick, has found it well tolerated despite large bony defects and probable perforations of the antral mucosa. DELAYED REDUCTION Successful results have followed delays of four weeks or longer, but where fibrosis has occurred and the bone ends in the fracture lines have resorbed some relapse is likely. When repair is delayed until the fracture has united sufficiently to prevent elevation in the usual way, surgical exploration followed by refracture is required. When bony union has occurred refracture is usually not possible and either onlay bone grafts or other synthetic materials are used. Dissection of fibrosed 412 FRACTURES OF THE ZYGOMATIC COMPLEX intra-ocular tissue is difficult and the result frequently disappointing as also is the late correction of enophthalmos. RARE COMPLICATIONS Loss of vision is a rare complication considering the frequency with which severe zygomatic complex injuries are seen. It rarely follows simple elevation and is presumably caused by penetration of the optic nerve by bony spicules, Traumatic compression of the third, fourth, fifth, and sixth cranial in the superior orbital fissure produces: (a) Ptosis. (b) Anaesthesia of the frontal, lacrimal, and infra-orbital nerve distributions. (c) Ophthalmoplegia with limitation of accommodation due to a dilated pupil. It is suggested that in the absence of signs of intra-ocular congestion the superior orbital fissure syndrome is caused by compression, rather than by retrobulbar haematoma or cavernous sinu's involvement6. Re- covery usually follows reduction of the fracture. Severe retro-ocular haemorrhage rarely follows elevation of the fracture causing spasm of the central retinal artery. Immediate decom- pression is essential to prevent a permanent loss of vision of the eye which rapidly becomes proptosed with a fixed dilated pupil. This condlition is known as the traumatic orbital apex syndrome. Incisions in the upper and lower near the outer were suggested7, but recently a trans,antral approach has been described combining the removal of blood clot from the antrum, with cannulation of the superior orbital artery followed by its infusion with papavarine and heparin to relieve the arterial spasm8. Pain may develop from a neuroma arising subsequent to section of the infra-orbital nerve. Acknowledgements I wish to thank my colleagues Mr. Gordon Hardman and Dr. Peter Thompson for their invaluable assistance with this paper. Mr. B. A. Jones, Mr. G. L. Hurley and Mrs. P. A. Ware (nee Martin) of the Department of Clinical Photography, and Mrs. D. Twamley for her untiring secretarial assistance.

REFERENCES 1. ROWE, N. L., and KILLEY, H. C. (1968) Fractures of the Facial Skeleton, 2nd edit. Edinburgh, Livingstone, p. 303. 2. PFEIFFER, R. L. (1943) Archs. Ophthal. 30, 718. 3. CONVERSE, J. M. (1969) Plastic and Maxillo- Symposium, Vol. 1. Saint Louis, The C. V. Mosby Company, p. 139. 4. STRANC, M. F. (1968) Proc. R. Soc. Med. 61, 494. 5. McCoY, F. J., et al. (1962) Plastic reconstr. Surg. 29, 381. 6. PIGGOT, T. A., and IRVING, M. H. (1966) Br. J. plast. Surg. 19, 264. 7. PENN, J., and EPSTEIN, E. (1953) Brit. J. plast. Surg. 6, 65. 8. VARLEY, E. W. B., HOLT-WILLAMS, A. D., and WATSON, P. G. (1968) Br. J. Oral. Surg. 6, 31. 413