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 Surgery, University Hospital of Wales, Cardiff Anatomy THE FRONTAL PROCESS of the zygomatic bone articulates superiorly with the frontal bone at the zygomatico-frontal suture, giving attachment on its orbital aspect to the suspensory ligament of the eye (Lockwood's) at the lateral orbital tubercle (Whitnall's). Posteriorly the zygomatic process of the zygomatic bone 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 temporal bone to form the zygomatic arch. The temporal fascia is inserted into the upper aspect of the arch and deep to it lies the temporalis muscle attached to the coronoid process of the mandible. Antero-inferiorly the bone articulates with the zygomatic process of the maxilla forming the lateral two-thirds of the inferior orbital margin and enclosing the infra-orbital nerve. In the orbit articulating with the greater wing of sphenoid above and the maxilla below, the bone forms part of the lateral boundary of the inferior orbital fissure. The zygo- matic bone forms the superior antero-lateral boundary of the maxillary antrum and, being part of the orbital skeleton, 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 cheek 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 palpebral fissure, 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 cranial fossa. 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 eyelid, cheek, upper lip and side of the nose. The upper incisor and canine teeth and adjacent gingival tissue supplied by the anterior superior dental nerve may be similarly affected. Anaesthesia of the 404 FRACTURES OF THE ZYGOMATIC COMPLEX forehead occurs when the frontal nerve is compressed in the superior orbital fissure (vide infra). Diplopia. This results from distortion of the orbital axis 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 inferior rectus muscle 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 base. 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 fat, 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 fibrosis 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 ligaments. (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. 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 temporal muscle. 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 eyelashes and lids relative to the supra-orbital ridges should be compared as an assessment of enopthalmos. Ecchymosis may be seen and bony crepitus 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. RADIOLOGY 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-frontal suture, 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 soft tissue. 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 temple, between the anterior and posterior branches of the superficial temporal artery, approximately at the level of the tip of the pinna. The incision is deepened to expose the thick bluish-white temporal fascia which must not be confused with its covering of several thinner layers of 407 RUSSELL HOPKINS aponeurosis. 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.