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Lateral Wall Advancement in Orbital Decompression
Lateral Wall Advancement in Orbital Decompression ALLAN E. WULC, MD, 1 JEFFREY C. POPP, MD/ SCOTT P. BARTLETT, MD 3
Abstract: Treatment of dysthyroid orbitopathy can be enhanced with a modified craniofacial approach using a lateral wall osteotomy, and anterolateral advancement and osteosynthesis in conjunction with medial and inferior wall orbital decompression. The technique of lateral wall advancement is described, and the results are discussed. While the authors advocate orbital decompression for dysthyroid optic neuropathy, advancement of the lateral orbital wall can easily be performed as an adjunct to the two- or three-wall decompression procedure. Advancement appears to increase the overall decompressive effect by providing a potential space where lateral expansion can occur and by enlarging the bony orbital volume. It also appears to lessen lid retraction and facilitates (and in some cases, obviates) the need for further lid retraction surgery. Ophthalmology 1990; 97:1358-1369
Orbital decompression is a well-accepted surgical procedure that is often indicated in the management of the dysthyroid patient with compressive optic neuropathy, exposure keratopathy, or malignant exophthalmos.'-26 While it is not universally accepted as a treatment for the cosmetic rehabilitation of the asymptomatic exophthalmic patient, 5 many authors have commented on the relative safety of the procedure3.4·' 8 •21 ·25 •26 and consider the disfiguring appearance of the exophthalmos as, at the very least, a relative indication for orbital decompression. A recent survey of orbital surgeons indicated that approximately 60% of surgeries are performed for the cosmetic deformity induced by the exophthalmos. 26 In orbital decompression, one or more and up to four walls of the orbit can be removed so that the orbital conOriginally received: September 21, 1989. Revision accepted: April 2, 1990. ' Orbital Service, Department of Ophthalmology, Hospital of the University of Pennsylvania, Scheie Eye Institute, Philadelphia. 2 Oculoplastic, Orbital and Oncology Service, Department of Ophthalmology, University of Nebraska Medical Center, Omaha. 3 Division of Plastic and Reconstructive Surgery, Center for Human Appearance, University of Pennsylvania, Philadelphia. Presented at the American Academy of Ophthalmology Annual Meeting, New Orleans, OctjNov 1989. The authors have no proprietary interest in the development or marketing of any of the products mentioned. Reprint requests to Allan E. Wulc, MD, Orbital Service, Department of Ophthalmology, Hospital of the University of Pennsylvania, Scheie Eye Institute, Philadelphia, PA 19104.
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tents can expand into the surgically created defect. The majority of decompressions performed by ophthalmologists are done as two-wall decompressions in which the orbit is decompressed medially and inferiorly. 26 Lateral wall decompression has fallen out of favor because clinical and experimental work has shown that relatively larger amounts of decompression can be obtained by removing other orbital walls.Z 6 •27 However, the abovementioned survey of orbital surgeons showed that approximately 20% of decompressions continue to be three-wall procedures in which the lateral wall is removed to gain greater proptosis reduction. 26 In 1969, Tessier described the technique of en bloc advancement of the supraorbital bar for the exorbitism of the craniofaciostenoses. 28 In exorbitism, such as is seen in Crouzon's disease or Apert's anomaly, the bony orbit is shallow and the soft tissue contents of the orbit do not fit within it. The overall facial morphology of the exorbitism of the craniofaciostenoses is similar to the exophthalmos of dysthyroid orbitopathy in which the bony orbit is normal in size but the orbital soft tissue content is increased. Tessier concluded that the orbital deformity of dysthyroid orbitopathy could be approached in a similar manner. Instead of decompressing the orbit into the adjacent sinuses by removing bone, with supraorbital advancement, the walls of the orbit could be displaced forward to expand the orbital volume. The bones of the orbit were osteotomized and moved forward and downward en bloc, filling any contour abnormality with onlay bone grafts (Fig 1). If necessary, dental relationships were preserved by performing a compensatory osteotomy of the
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Fig 1. Lefort III osteotomy with midfacial advancement described for severe exophthalmos. Arrow indicates direction of displacement of midface. Hatched lines indicate area of contour bone grafts. (Reprinted with permission from Tessier P. Expansion of the orbital cavity. In: Tessier P, ed. Plastic Surgery of the Orbit and Eyelids. New York: Masson, 1981; 107-17.)
maxilla. 28 - 30 This procedure requires a craniotomy (and the combined efforts of a craniofacial surgeon and a neurosurgeon) and prolonged intermaxillary fixation and was reserved for severe cases. While we have not had occasion to see or review any material with regard to the results of this procedure in Graves' orbitopathy, results in the craniofaciostenoses indicate little bone resorption and favorable alterations in facial morphology with long-term follow-up through adolescence and into adulthood. 31 - 33 In more moderate cases of orbitopathy, Tessier advocated orbital expansion by lowering the orbital floor, by valgus osteotomy of the zygoma, and by mesial displacement of the lamina papyracea, alone or in combination depending on the degree of exophthalmos. To perform the valgus osteotomy, a bicoronal approach to the orbits was employed. Saw cuts were made in the zygoma and frontal bone along the lateral orbital wall, and the zygomatic arch was greenstick fractured so as to rotate the malar complex and lateral orbital wall outward (Fig 2)_2 8- 30 A similar approach was described by Wolfe that did not require a greenstick fracture and has produced good results. 34- 36 Wolfe also emphasized that the periorbita should not be violated to avoid postoperative motility
Fig 2. Top, Tessier's orbital expansion for dysthyroid orbitopathy. Dotted lines outline horizontal and vertical osteotomy sites (Reprinted with permission from Tessier P. Expansion of the orbital cavity. In: Tessier P, ed. Plastic Surgery of the Orbit and Eyelids. New York: Masson, 1981; 107-17.) Bottom, valgus osteotomy of malar bone. Bone wired in place, rotated outward and posteriorly (arrow). Ethmoidal infracture is shown. Hatched lines indicate lowered orbital floor. Dots indicate onlay bone grafts. Arrow indicates area of greenstick fracture. (Reprinted with permission from Tessier P. Expansion of the orbital cavity. In: Tessier P, ed. Plastic Surgery of the Orbit and Eyelids. New York: Masson, 1981; 107-17.)
problems. 35 Perhaps the reluctance of patients to undergo a "craniofacial" procedure, or perhaps established referral patterns of dysthyroid patients to ophthalmic surgeons who are more familiar with decompressive techniques, accounts for the fact that these techniques do not enjoy wider acceptance. We describe a modified technique of three-wall decompression (lateral wall, medial wall, and floor) that can be used by the experienced orbital surgeon. It is a modification of Tessier's valgus osteotomy that is done in conjunction with a three-wall orbital decompression. The lateral wall of the orbit is removed as in conventional lateral orbitotomy and replaced in a forward and outward position. While the lateral wall is out, antralethmoidal decompression is accomplished. We believe that posterior 1359
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orbital decompression into the ethmoidal sinuses is essential to the appropriate surgical management of dysthyroid optic neuropathy. However, moving the lateral wall outward and anteriorly increases the amount of decompression that can be attained laterally by increasing the horizontal and sagittal length of the bony orbit and, hence, increases the bony orbital volume. It also provides a potential space behind the advanced rim into which lateral orbital decompression can occur. Removing the lateral wall before antralethmoidal decompression facilitates surgery in the medial orbital apex, because the orbital contents can be mobilized laterally, thus aiding visualization. Our preliminary results in nine patients suggest that facial morphology is enhanced. In contradistinction to other methods of orbital decompression in which upper eyelid retraction often gets worse, orbital advancement appears to lessen the degree of lid retraction associated with orbitopathy and facilitates (and in some cases, obviates) the need for lid retraction surgery.
TECHNIQUE With the patient under general endotracheal anesthesia, the lower eyelid and lateral canthal area are infiltrated with bupivacaine (Marcaine) 0.5% with 1 to 200,000 adrenaline solution. The nose is packed with oxymetazoline (Afrin, 0.05%) on 3" X 'h'' neurosurgical cottonoids. The patient is prepared and draped in the usual sterile manner. A protective corneoscleral shell is placed. A broad-spectrum antibiotic is infused. A 3-cm horizontal incision is made from the lateral canthal angle (Fig 3). Anteriorly, a lateral canthotomy and inferior limb cantholysis are performed; posteriorly, the incision is deepened through orbicularis using a needle tip monopolar cutting cautery. A skin muscle flap is raised posterior to the orbital rim both superiorly and inferiorly to expose the zygomatic periosteum and the superficial temporalis fascia. Wide undermining is necessary to obtain good exposure of the superior and inferior portion of the lateral orbital wall. The zygomatic periosteum is incised 3 mm lateral to the orbital entrance site from above the frontozygomatic suture to the level of the orbital floor. Two 2.5-cm relaxing incisions are made in periosteum, one horizontally along the superior border of the zygomatic arch and the other at the junction ofthe temporalis fascia and the epicranium at the superior temporal crest. The temporalis muscle is reflected from its insertion at the crest and out of the temporalis fossa using a periosteal elevator. Bone wax may be necessary to control bleeding through venous dipoloe. The elevator is then used to reflect periorbita from the lateral wall of the orbit and for approximately 1 em along the roof and floor. At this point, horizontal osteotomies with an oscillating saw are made in the lateral wall, from the floor of the orbit at the level of the superior border of the zygomatic arch, and at the zygomatic arch above the frontozygomatic suture within the lacrimal fossa (Fig 4, top center and top right). In this manner, between 3 and 4 em ofbone is routinely removed. 1360
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The bone is placed in a blood-soaked sponge. A diamond drill is used to remove bone behind the sphenozygomatic suture until the bleeding marrow of the greater wing of the sphenoid is observed (Fig 5). Alternatively, doubleaction rongeurs can be used. An inferior limb cantholysis is performed and the lower eyelid is distracted downward using two Blair retractors. An incision is made at the lower border of the tarsus from the lateral cantholysis to a level immediately beneath the inferior punctum using a needle point monopolar cutting cautery. The incision transects the lower eyelid retractors and orbital septum and exposes a plane for a skin muscle flap that is raised to the orbital floor using a combination of cutting cautery and blunt cotton-tip applicator dissection. The Blair retractors are then replaced with a large vein retractor, and the lid is vigorously retracted. With a finger pressed on the lower eyelid retractors, the arcus marginalis and the floor of the orbit are readily visualized and palpated. The periosteum of the orbital floor is incised with the cutting cautery from the inferior osteotomy site as in blowout fracture repair and the periosteum of the floor of the orbit is dissected from the floor using a Freer elevator. Soule retractors are placed in the orbit. With a hemostat, the bony orbital floor is punctured medial to the infraorbital groove. Floor bone is then removed posterior to the midaxis of the globe with a Kerrison rongeur or a pituitary forceps as far as the posterior wall of the antrum (Fig 6). The bone lateral to the groove is likewise punctured with a hemostat, avoiding the inferior orbital fissure. The bone surrounding the neurovascular bundle is then separated and removed with 0.3 mm forceps such that the neurovascular bundle is free within the maxillary sinus. With the floor and lateral wall removed, the orbital contents including the globe can be mobilized laterally with Soule retractors to obtain excellent visualization of the medial wall and medial orbital apex (Fig 7). The periosteum of the medial wall is freed to the level of the ethmoidal foraminae, and bone and ethmoidal sinuses are exenterated with Wilde forceps until the thickened bone of the optic canal is reached. The inferior, medial, and posterolateral periorbita is then incised with an arachnoid knife and partially removed. It is essential to leave the anterolateral periorbita intact so that the lower lid can be reattached when the canthus is reformed at the time of closure. Orbital fat should freely prolapse into the medial ethmoids, the antrum, and into the temporalis fossa. If desired, anterior orbital fat may be resected, cauterizing any bleeders with bipolar cautery. At this time, the lateral wall advancement is accomplished. The lateral wall bone is now replaced in its normal anatomic position (Fig 4, top right). It is then advanced approximately 4 mm anteriorly and 2 mm laterally into its osteotomized position (Fig 4). The bone is then rigidly fixated with two Synthes four-hole orbital reconstruction miniplates (Fig 8). This is done by bending soft metallic templates to conform to the osteotomy, followed by bending the titanium miniplates to match the templates. Drill holes are placed in the frontal bone and the zygomatic bone followed by drill holes in the free bone. This
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Fig 3. Top left, incision for lateral portion of orbital advancement, 3 em horizontally from the lateral canthus. Fig 4. Top center, site of bony horizontal osteotomies. Top right, case 3. Site of bony horizontal osteotomies. Bottom left, vectors of rotation. Bone is advanced fmward approximately 3 mm, then 2 mm laterally. Slight external and outward rotation is applied (see also Fig 3). Bottom right, case 3. Bone in osteotomized position, advanced approximately 3 mm forward and 2 mm laterally.
free bone is fixated in the advanced position with a Synthes bone holding clamp, and soft tissues are protected with the Synthes soft tissue guard. Then, 1.5 mm self-tapping titanium screws are passed, and the bone is rigidly fixated in the osteotomized position (Fig 8). We feel that the rim of the replaced bone that projects anteriorly might be palpable, or even noticed by the patient. For this reason, methylmethacrylate bone cement (Cranioplast) is applied to the advanced bone edge, sculpted, allowed to set, and then contoured further with a diamond drill (Fig 9). Alternatively, we have used bone removed during the decompression as a free onlay bone graft. The subcutaneous tissues are then closed in the following fashion: two 7-0 Vicryl sutures are passed from the lower lid retractors to the lower border of the tarsus and tied loosely in buried interrupted fashion. A lateral canthopexy is now performed. A 6-0 proline suture is placed through the lateral border of the lower tarsus and sutured
to the periosteum inside the orbital rim with a horizontal mattress suture. The lateral canthal angle is reformed with a 6-0 silk suture. The temporalis fascia is reattached with a 4-0 chromic suture to the epicranium at the superior temporal crest. The periorbita is then sutured to the zygomatic periosteum and its attached temporalis fascia with 4-0 chromic sutures. Because the lateral wall of the orbit has been advanced anteriorly, it is difficult not to suture this aspect of the wound under tension, and it is often helpful to use interrupted vertical mattress sutures. A potential space is created behind the advanced and laterally displaced rim that is devoid oftemporalis and is bordered by the zygomatic periosteum on stretch into which the orbital fat can prolapse (Fig 10). A subcutaneous closure is accomplished with 5-0 chromic sutures, the skin is closed with a running 6-0 proline suture, and the wound is dressed with Steristrips. Ten milligrams of intravenous dexamethasone is infused. No patches are applied. The patient is kept at bedrest with 1361
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the head of the bed elevated 30°, and receives iced saline compresses, intravenous and topical antibiotics, and intravenous dexamethasone in tapering doses for 2 days. The patient is discharged on the third postoperative day.
In all patients, lower lid retraction decreased postoperatively by an average of 2 mm. Upper lid scleral show also decreased by an average of 2 mm (range, 0-4 mm). No ptosis was produced with the technique described. In cases where upper lid retraction changed little with the procedure, a change in the amount of retraction in the area temporal to the limbus was nonetheless observed, and consequently, eyelid appearance was enhanced (Fig 12). A single patient developed recurrent upper eyelid retraction 13 months postoperatively, after an initial drop in the lid of 5 mm, that was possibly due to continued progression of her orbitopathy. Five patients had significant diplopia preoperatively: all of them had diplopia postoperatively, and in three, the decompression appeared to worsen the strabismus. All eight orbits with optic neuropathy had improved acuities postdecompression. No postoperative radiation or longterm steroids were required. Infraorbital hypesthesia was observed in two orbits; it has persisted beyond a year in one of these. No lid mal positions have ensued from advancing the lateral wall forward. Representative preoperative and postoperative photographs are presented in Figures 11 and 12. In three patients for whom predecompression planning had included the need for upper and lower lid retractor recession, a lessening of lid retraction occurred such that no lid retraction surgery was required. In two additional patients, instead of retractor recession, blepharoplasty with removal of fat corrected the residual deformity.
PATIENTS AND METHODS
DISCUSSION
Nine patients from the Orbital and Oculoplastic Service at the University of Pennsylvania and the University of Nebraska were decompressed and advanced with the technique described. Three of these patients underwent bilateral decompression and lateral rim advancement. All patients received a full ophthalmic evaluation that included a visual field and computed tomography scan. All preoperative and postoperative exophthalmometry measurements were done with the Naugle exophthalmometer, which is not based at the orbital rims. 37 Indications for decompression were optic neuropathy in five patients (eight orbits), threatened corneal perforation from malignant exophthalmos in two patients (two orbits), exposure keratopathy in one patient, and cosmesis purposes in one patient.
The traditional approach to orbital decompression has been to remove one or more walls of the orbit, allowing the orbital contents to herniate into the potential space created by the surgeon. A technique for removal of every wall of the orbit has been devised. Two-, three-, and fourwall decompressions can be accomplished in combination and have been reported with good results and with varied rates and types of complications. 1•6 •18 •20- 25 In a recent survey of orbital surgeons, 75% of decompressions were performed as two-wall decompressions with removal of the floor and medial wall. These procedures were performed either via the translid route or via the transantral route. 26 This same review concluded that the transantral approach provided the best "final visual acuity" due to the better apical visualization and more complete optic nerve decompression, and was therefore preferred for cases of compressive optic neuropathy. 26 Although widely accepted, the antralethmoidal decompression is not without its problems. There is a significant risk of postoperative strabismus, and this is especially true in transantral decompression. 26 Reasons for the increase in motility problems are not clear; however, it is our impression that surgery in the medial orbital apex may disturb the muscles at their insertions, particularly the medial rectus. We currently attempt not to remove the small ridge of floor bone adjacent to the optic strut
Fig 5. Temporal decompression along sphenoid with diamond burr. Alternatively. bone biting rongeurs can be used.
RESULTS The three-wall decompression with lateral orbital advancement has been performed on a total of 12 orbits in nine patients. The mean amount of decompression was 6.6 mm (range, 3-10 mm). As in most other studies, the greater the initial proptosis, the greater the amount of final decompression. 1362
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Fig 6. Top left, transconjunctival approach to orbit with swinging lower eyelid flap and direct view of orbital floor as in blowout fracture repair. Fig 7. Top right, mobilization ofthe orbit laterally into the defect in the lateral wall exposes the apex and encourages direct visualization of apical structures. Hatched lines, area decompressed. Fig 8. Center left, case 3. Bone fixated in osteotomized position with Synthes titanium miniplates. Center right, bone fixated in osteotomized position, outward and forward, with Synthes titanium mini plates. Fig 9. Bottom left, edge of advanced bone contoured with Cranioplast bone cement. Bone dust or onlay fragments may also be used if anchored firmly under periosteum. Bottom right, edge of advanced bone contoured with Cranioplast (blue hatched lines: area contoured with Cranioplast).
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Fig 10. Left, postoperative computed tomographic scan demonstrates potential space behind the advanced lateral orbital rim (arrow). Right, potential space behind advanced lateral wall (arrow).
so as to avoid this complication. Because of the significant risk of postoperative strabismus, Leone et al recently sought alternatives to the antral ethmoidal decompression and described a medial and lateral approach to the orbit that avoids the floor entirely with no postoperative impairments in motility in their series. 20 Originally described by Kronlein, 38 the single-wall lateral decompression is the oldest decompressive procedure and is familiar to most ophthalmologists. It has been modified by Guyton, Berke, Moran, Long and Ellis, and recently by Trokel and Cooper. 8 •10- 12 •27 Variations on the original procedure include incisions into the temporalis muscle, excision of temporalis muscle, and removal of the orbital rim. 8 •10- 12 •27 However, the procedure has fallen out of favor for a variety of reasons: large amounts of decompression are not possible, the bulky temporalis muscle often expands and blocks any herniation of orbital tissue into the temporalis fossa, the procedure may produce its own cosmetic deformity, and postoperative ex-
ophthalmometry readings based at the orbital rim become impossible. 21 •27 •37 Finally, work done in dried skulls has suggested that little volume can be added to the orbit by expanding it laterally. 39 •40 Several factors, however, militate against dismissing the lateral wall approach altogether. Removal of the lateral wall is technically straightforward and allows easy access to the orbit posterior to the midaxis of the globe. An experimental study in cadavers showed that removing the lateral wall of the orbit provided as much proptosis reduction as removal of the medial wall. 41 Additionally, removing the lateral wall before performing medial and inferior decompression enhances visualization of the orbital apex. With the bone removed, the orbital contents can be mobilized in the direction of the temporalis fossa without the interference of the proptotic globe pressing against the lateral orbital rim. This lateral displacement of the orbit is similar to a reported approach for access to the medial posterior intraconal space in which medial
Fig 11. Case 3. Top left, preoperative Naugle Hertel reading, 23 mm. Top right, 3 months postoperative decompression and lateral wall advancement in both eyes. Naugle Hertel reading, 16 mm. Bottom left, preoperative photograph. Bottom right, 3 months postoperative photograph.
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Fig 12. Case 9. Left. preoperative Naugle Hertel reading, 23.5 mm. Right, 3 months postoperative after orbital decompression and lateral wall advancement to the left eye only. Naugle Hertel reading, 19.5 mm. Notice unilateral decrease in temporal upper eyelid retraction on advanced side. Fissure size decreased by 0.5 mm. There was no change in lower eyelid position.
intraconal surgery is preceded by a lateral wall "outfracturing."42 Superior visualization of the orbital apex is obtained, permitting the surgeon an enhanced view of the ethmoids, and access to the ethmoidal foraminae and the medial and inferior walls of the optic canal. In all patients who required decompression for compressive optic neuropathy (eight orbits, five patients), the procedure yielded an improved final visual acuity. While the actual number of cases is small, it nonetheless suggests that this technical addition to the routine translid procedure may be as effective in improving "final visual acuity" as is the most commonly used procedure for dysthyroid optic neuropathy, the Ogura procedure.Z6 We believe that posterior orbital apical decompression is essential for good visual outcome in patients with dysthyroid optic neuropathy, and we have routinely performed decompression in conjunction with advancement; we are not confident that a lateral wall advancement alone would suffice to correct a posterior compressive optic neuropathy. We feel that lateral wall advancement enjoys several technical and aesthetic advantages over the conventional techniques of three-wall decompression. A sliding osteotomy of the lateral orbital wall displaces the lateral orbital wall outward and forward, creates additional entrance width to the orbit, and expands the orbital sagittal length. The bony orbital confines are enlarged. As in valgus osteotomy, or en bloc advancement, the size of the bony orbit is expanded, the relationship between the bony and soft tissue orbit becomes more appropriate, and exophthalmos is thereby reduced. While other authors have noted that the temporalis muscle may interfere with the expansion of orbital soft tissue in lateral orbital decompression,Z 7 with the lateral wall advancement technique, a space is created in the temporalis fossa into which orbital soft tissue can prolapse. When the lateral wall is advanced outward and forward, the temporalis fascia and muscle are placed on stretch and also are displaced outward and forward. This potential space behind the advanced rim can be observed at the time of surgery (Fig 10). 1366
Finally, in contrast to other approaches to orbital decompression in which the amount of upper eyelid retraction is usually increased following the procedure, 26 it appears that upper and lower eyelid position are more favorably affected with the sliding osteotomy approach. In all of our cases, lower eyelid position was improved by orbital advancement. The upper lid also appeared to be more favorably affected. In all but one case, upper eyelid retraction improved. The improvement either took the form of a more normal lid contour with a lessening of temporal eyelid retraction or an actual change in upper eyelid position. In three cases, the lid retraction was reduced to the point that no additional lid surgery was required; in two other patients, additional appearance enhancement was attained with blepharoplasty alone. We have several postulates for why orbital advancement may reduce eyelid retraction. ( 1) A lateral canthopexy is performed at the time of closure of the incisions. Lower lid position may be slightly improved because the lower lid is tightened and raised laterally at the lateral canthus. (2) With lateral wall advancement, the lateral retinaculum is also advanced forward with its attached Lockwood's and Whitnall's ligaments. Upper and lower eyelid retraction may be reduced because the lids and their anterior attachment points are also pushed forward over the decompressed globe. (3) Sliding the lateral wall of the orbit laterally and anchoring the lateral canthus and its attachments to the displaced bone tightens the lids horizontally and hence reduces the amount of their curvature, and may lessen lid retraction. Stretching normal or retracted upper and lower eyelids laterally can be seen to reduce the size of the vertical fissure (Fig 13). Our technique may also offer several advantages over the described craniofacial approaches to the orbit. In contrast to the techniques described by Tessier and modified by Wolfe, a bicoronal approach is not necessary.28-30·34-36 We have found that patient acceptance of lid incisions for orbital surgery has been greater than that for ear-to-ear incisions. A lid incision is easily and cos-
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Fig 13. Left, patient with 2 mm of upper eyelid retraction. Right, manual distraction of eyelid laterally produces ptosis. Lateral displacement of lateral canthus may account, in part, for lessening of eyelid retraction after lateral wall osteotomy.
metically concealed, and usually heals with less associated facial swelling. Our technique is also more familiar to most orbital surgeons. A segment of zygomatic bone is osteotomized rather than the entire lateral malar complex or the entire orbital roof as in the craniofacial approaches. We feel that removal of the lateral wall alone without the malar eminence suffices to correct the problem. In Tessier's valgus osteotomy technique, a greenstick fracture is created in the zygomatic arch that could potentially injure the facial nerve. 28- 30 In both Tessier and Wolfe's described techniques, vertical osteotomies are required. 28- 30·34- 36 None of these surgical maneuvers is required with our technique. Horizontal osteotomies of the lateral wall are routine in the conventional lateral orbitotomy procedure. In all of our cases, we moved the lateral wall forward 4 mm and laterally 2 mm. To date, we have not seen an overcorrection with the technique. We feel that even with larger amounts of proptosis, a wider or more anteriorly placed osteosynthesis might produce a cosmetic deformity, and possibly enophthalmos as well, and we have titrated our decompression to fit the degree of proptosis and not the osteotomy. It is a matter for future research as to whether these numbers are indeed optimum. Our indications for lateral wall advancement are evolving. We have used the technique as an adjunct to orbital decompression and for indications for which a routine orbital decompression would be performed, i.e., dysthyroid optic neuropathy, exposure keratopathy, corneal ulcer, or cosmetic reasons. In the latter category, we routinely discuss the potential surgical management of orbitopathy along with risks and come to a decision influenced by the degree of disfigurement and by the patient's willingness to accept the higher risk inherent with decompression than with lid surgery alone. If decompression is selected as a surgical option, we perform lateral wall advancement routinely in conjunction with the orbital decompression. While it would be exciting to speculate that anterolateral advancement of the lateral orbital wall is an excellent technique for enhancing facial ap-
pearance in patients with the dysmorphic appearance of Graves' orbitopathy, we do not feel that a lateral orbitotomy and an advancement osteotomy are routinely indicated in patients with eyelid retraction. Other less involved techniques can be performed on an outpatient basis under local anesthesia with less attendant risks. t-s Our procedure demands the use of craniomaxillofacial miniplates. Compression plates have been used with great effectiveness in the treatment of mandibular fractures,43·44 in advancement of the maxilla, in orthognathic surgery, 45 -48 and in the treatment of fractures and deformities of the facial skeleton. 44·49 It is vital that the osteotomized bone of the lateral wall be kept in rigid fixation in its new position so that osteosynthesis can occur. In the absence of rigid skeletal fixation, we feel that with our procedure, the action of the temporalis muscle would tend to countermand the effectiveness of an osteotomy performed with point-to-point wire fixation, and the bone of the lateral orbital rim could be pulled back into the normal anatomic position. Furthermore, miniplates allow the surgeon to advance the bone with a more precise spatial orientation than could be obtained with wire alone. The plates are made of titanium and are made by AO/ASIF (Synthes Maxillofacial, Paoli, PA). They are inert, corrosion resistant, and biocompatible, and they do not need to be removed. Courses are given throughout the country to familiarize the surgeon with their use. While we have had occasion to use other systems (the Luhr miniplate system, Howemedica, Rutherford, NJ; the Wurzberg system, Walter Lorenz, Jacksonville, FL), our experience with them is limited to two of the described cases. To date, we have had no complications with any of the available orbital reconstruction plates. The most timeconsuming and tedious portion of the procedure is bending the plate to fit the osteotomized bone because only a perfect angulation of the plate will fixate the bone in the desired position. Unlike wire fixation where the bone may recontour with time and the positioning of drill holes is not critical, with rigid fixation, the position of the bone after the self-tapping screws are placed represents the final 1367
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position, and there is little margin for error (Fig 8). Methylmethacrylate bone cement (Cranioplast) is well described for contouring of bone in the orthopedic, craniofacial, and neurosurgical literature. 50- 54 It has also been used as an orbital volume substitute. 55 We use Cranioplast as a means of creating a smooth, anteriorly displaced orbital rim. To date, we have had no complications from its use. In our last two cases, influenced by our craniofacial surgical colleague, we have used autogenous bone harvested from the lateral wall decompression as an onlay contouring free graft fixated under periosteum, but we do not have enough follow-up data to make a comment regarding its long-term efficacy. While our series of cases is small, we are nonetheless encouraged by the significant advantages offered by lateral orbital rim advancement and expansion when done in conjunction with antralethmoidal decompression, both from a visualization of the orbital apex and a cosmetic standpoint. While postoperative motility disturbance remains a problem, as it has in other antralethmoidal decompression series, a recent article suggesting that postoperative morbidity can be significantly decreased with a combined medial and lateral approach to the orbit that leaves the floor of the orbit intact is intriguing. 20 It may well be that two-wall decompression with lateral wall decompression and advancement in combination with a medial approach will prove to be our future technique of choice.
REFERENCES 1. Linberg JV, Anderson RL. Transorbital decompression: indications and results. Arch Ophthalmol1981; 99:113-9. 2. Hurwitz JJ, Birt D. An individualized approach to orbital decompression in Graves' ophthalmopathy. Arch Ophthalmol1985; 103:660-5. 3. Kennerdell JS, Maroon JC, Buerger GF. Comprehensive surgical management of proptosis in dysthyroid orbitopathy. Orbit 1987; 6: 153-79. 4. Shorr N, Seiff SR. The four stages of surgical rehabilitation of the patient with dysthyroid ophthalmopathy. Ophthalmology 1986; 93: 476-83. 5. Frueh BR. Graves' eye disease. In: Waltman SR, Keates RH, Hoyt CS, et al, eds. Surgery of the Eye. Vol. 2. New York: Churchill Livingstone, 1988; 719-32. 6. Nafziger HC. Progressive exophthalmos following thyroidectomy: its pathology and treatment. Ann Surg 1931; 94:582-6. 7. Sewall EC. Operative control of progressive exophthalmos. Arch Otolaryngol 1936; 24:621-4. 8. Guyton JS. Decompression of the orbit. Surgery 1946; 19:790-809. 9. Hirsch 0. Surgical decompression of malignant exophthalmos. Arch Otolaryngol 1950; 51:325-34. 10. Berke RN. A modified Kronlein operation. Trans Am Ophthalmol Soc 1953; 51:193-231. 11. Moran RE. The correction of exophthalmos and levator spasm. Plast Reconstr Surg 1956; 18:411-26. 12. Long JC, Ellis GO. Temporal decompression of the orbit for thyroid exophthalmos. Am J Ophthalmol1966; 62:1089-98. 13. Ogura JH. Transantral orbital decompression for progressive exophthalmos: a follow-up of 54 cases. Med Clin North Am 1968; 52:399407.
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14. Surgical approach to the ophthalmopathy of Graves' disease. JAMA 1971; 216:1627-31. 15. Ogura JH, Thawley SE. Orbital decompression of exophthalmos. Otolaryngol Clin North Am 1980; 13(1):29-38. 16. Lanier V Jr. The surgical treatment of exophthalmos. Plast Reconstr Surg 1975; 55:56-64. 17. Calcaterra TC. Paranasal sinus decompression of the orbit in Graves' disease. Ophthalmic Surg 1977; 8(2):80-4. 18. Leone CR Jr, Bajandas FJ. Inferior orbital decompression for thyroid ophthalmopathy. Arch Ophthalmol1980; 98:890-2. 19. Leone CR Jr. The management of ophthalmic Graves' disease. Ophthalmology 1984; 91:770-9. 20. Leone CR Jr, Piest KL, Newman RJ. Medial and lateral wall decompression for thyroid ophthalmopathy. Am J Ophthalmol 1989; 108:160-6. 21. Baylis HI, Call B, Shibata CS. The transantral orbital decompression (Ogura technique) as performed by the ophthalmologist: a series of 24 patients. Ophthalmology 1980; 87:1005-12. 22. Small RG, Meiring NL. A combined orbital and antral approach to surgical decompression of the orbit. Ophthalmology 1981; 88:542-7. 23. Anderson RL, Linberg JV. Transorbital approach to decompression in Graves' disease. Arch Ophthalmol1981; 99:120-4. 24. McCord CD Jr. Orbital decompression for Graves' disease: exposure through lateral canthal and inferior fornix incision. Ophthalmology 1981; 88:533-41. 25. Kennerdell JS, Maroon JC. An orbital decompression for severe dysthyroid exophthalmos. Ophthalmology 1982; 89:467-72. 26. McCord CD Jr. Current trends in orbital decompression. Ophthalmology 1985; 92:21-33. 27. Trokel SL, Cooper WC. Orbital decompression: effect on motility and globe position. Ophthalmology 1979; 86:2064-70. 28. Tessier P. Expansion chirurgicale de l'orbite. Ann Chir Plast 1969; 14: 207-14. 29. Tessier P. Total osteotomy of the middle third of the face for faciostenosis or for sequelae of Le Fort Ill fractures. Plast Reconstr Surg 1971; 48:533-41. 30. Tessier P. Expansion of the orbital cavity. In: Tessier P, ed. Plastic Surgery of the Orbit and Eyelids. New York: Masson, 1981; 107-17. 31. Kaban LB, Conover M, Mulliken JB. Midface position after Le Fort Ill advancement: a long-term follow-up study. Cleft Palate J 1986; 23(Suppl 1):75-7. 32. Ousterhout OK, Vargervik K. Aesthetic improvement resulting from craniofacial surgery in craniosynostosis syndromes. J Craniomaxillofac Surg 1987; 15:189-97. 33. Whitaker LA, Bartlett SP. The craniofacial dysostoses: guidelines for management of symmetric and asymmetric disease. Clin Plast Surg 1987; 14:73-81. 34. Wolfe SA. Surgical treatment of exophthalmos and enophthalmos. Ann Ophthalmol1981; 13:995-1002. 35. Wolfe SA. Modified three-wall orbital expansion to correct persistent exophthalmos or exorbitism. Plast Reconstr Surg 1979; 64:448-55. 36. Wolfe SA, Hemmy D. How much does moving the lateral wall help in expanding the orbit? Ophthalmic Plast Reconstr Surg 1988; 4:111-4. 37. Naugle TC. Methodology and measurement with lateral orbitotomy. In: Henkes HE. Metabolic Eye Diseases: Proceedings of the Vllth Congress of the European Society of Ophthalmology. Helsinki: Patrons Association of the European Ophthalmological Society, 1985; 54950. 38. Kronlein RU. Zur pathologie und operaten Behandlung der Dermoidcysten der Orbita. Beitr Klin Chir 1888; 4:149-63. 39. Stabile JR, Trokel SM. Increase in orbital volume obtained by decompression in dried skulls. Am J Ophthalmol1983; 95:327-31. 40. McCord CD Jr, Putnam JR, Ugland D. Pressure-volume orbital mea-
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44.
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surement comparing decompression approaches. Ophthalmic Plast Reconstr Surg 1985; 1:55-63. Pearl RM. Surgical management of volumetric changes in the bony orbit. Plast Surg Forum, Vll11985; 45:105-106. McCord CD Jr. A combined lateral and medial orbitotomy for exposure of optic nerve and orbital apex. Ophthalmic Surg 1978; 9(3):58-66. Spiess! B. Rigid internal fixation after sagittal split osteotomy of the ascending ramus. In: Spiess! B, ed. New Concepts in Maxillofacial Bone Surgery. Berlin: Springer-Verlag, 1976:115. Texhammar R, Schmoker R. Stable Internal Fixation in Maxillofacial Bone Surgery: A Manual for Operating Room Personnel. Berlin: Springer-Verlag, 1984. Luyk NH, Ward-Booth RP. The stability of Le Fort II advancement osteotomies using bone plates without bone grafts. J Craniomaxillofac Surg 1985; 13:250-3. Harsha BC, Terry BC. Stabilization of Le Fort I osteotomies utilizing small bone plates. lnt J Adult Orthod Orthognathic Surg 1986; 1:6977. Rosen HM. Miniplate fixation of LeFort I osteotomies. Plast Reconstr Surg 1986; 78:748-55.
48. Holtje WJ. Midfacial osteotomies in patients with cleft lip, alveolus and palate. Aust N Z J Surg; 1987; 57(2):89-99. 49. Beals SP, Munro IR. The use of miniplates in craniomaxillofacial surgery. Plast Reconstr Surg 1987; 79:33-8. 50. Volz RG, Kloss J, Peltier LF. The use of methylmethacrylate as a temporary spacer following en bloc resection of the distal femur: a case report. Clin Orthop 1980; 147:185-7. 51. Dorr LD. Treatment of hip fractures in elderly and senile patients. Orthop Clin North Am 1981; 12:153-63. 52. Pochon JP. The repair of congenital and acquired skull defects in childhood. J Pediatr Surg 1982; 17:31-6. 53. Ousterhout DK, BakerS, Zlotolow I. Methylmethacrylate onlay implants in the treatment of forehead deformities secondary to craniosynostosis. J Maxillofac Surg 1980; 8:228-33. 54. Steimie R, Bourghli A, Jacquet G, et al. Cranioplasty with acrylic methyl methacrylate resin: modified procedure-technical note. Zentrabl Neurochir 1986; 47:24-7. 55. Wilkins RB, Kulwin DR, McCord CD Jr, Tanenbaum M. Skin and tissue techniques. In: McCord CD, Tanenbaum M, eds. Oculoplastic Surgery, 2nd ed. New York: Raven, 1987; 37.
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Abstract: Treatment of dysthyroid orbitopathy can be enhanced with a modified craniofacial approach using a lateral wall osteotomy, and anterolateral advancement and osteosynthesis in conjunction with medial and inferior wall orbital decompression. The technique of lateral wall advancement is described, and the results are discussed. While the authors advocate orbital decompression for dysthyroid optic neuropathy, advancement of the lateral orbital wall can easily be performed as an adjunct to the two- or three-wall decompression procedure. Advancement appears to increase the overall decompressive effect by providing a potential space where lateral expansion can occur and by enlarging the bony orbital volume. It also appears to lessen lid retraction and facilitates (and in some cases, obviates) the need for further lid retraction surgery. Ophthalmology 1990; 97:1358-1369
Orbital decompression is a well-accepted surgical procedure that is often indicated in the management of the dysthyroid patient with compressive optic neuropathy, exposure keratopathy, or malignant exophthalmos.'-26 While it is not universally accepted as a treatment for the cosmetic rehabilitation of the asymptomatic exophthalmic patient, 5 many authors have commented on the relative safety of the procedure3.4·' 8 •21 ·25 •26 and consider the disfiguring appearance of the exophthalmos as, at the very least, a relative indication for orbital decompression. A recent survey of orbital surgeons indicated that approximately 60% of surgeries are performed for the cosmetic deformity induced by the exophthalmos. 26 In orbital decompression, one or more and up to four walls of the orbit can be removed so that the orbital conOriginally received: September 21, 1989. Revision accepted: April 2, 1990. ' Orbital Service, Department of Ophthalmology, Hospital of the University of Pennsylvania, Scheie Eye Institute, Philadelphia. 2 Oculoplastic, Orbital and Oncology Service, Department of Ophthalmology, University of Nebraska Medical Center, Omaha. 3 Division of Plastic and Reconstructive Surgery, Center for Human Appearance, University of Pennsylvania, Philadelphia. Presented at the American Academy of Ophthalmology Annual Meeting, New Orleans, OctjNov 1989. The authors have no proprietary interest in the development or marketing of any of the products mentioned. Reprint requests to Allan E. Wulc, MD, Orbital Service, Department of Ophthalmology, Hospital of the University of Pennsylvania, Scheie Eye Institute, Philadelphia, PA 19104.
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tents can expand into the surgically created defect. The majority of decompressions performed by ophthalmologists are done as two-wall decompressions in which the orbit is decompressed medially and inferiorly. 26 Lateral wall decompression has fallen out of favor because clinical and experimental work has shown that relatively larger amounts of decompression can be obtained by removing other orbital walls.Z 6 •27 However, the abovementioned survey of orbital surgeons showed that approximately 20% of decompressions continue to be three-wall procedures in which the lateral wall is removed to gain greater proptosis reduction. 26 In 1969, Tessier described the technique of en bloc advancement of the supraorbital bar for the exorbitism of the craniofaciostenoses. 28 In exorbitism, such as is seen in Crouzon's disease or Apert's anomaly, the bony orbit is shallow and the soft tissue contents of the orbit do not fit within it. The overall facial morphology of the exorbitism of the craniofaciostenoses is similar to the exophthalmos of dysthyroid orbitopathy in which the bony orbit is normal in size but the orbital soft tissue content is increased. Tessier concluded that the orbital deformity of dysthyroid orbitopathy could be approached in a similar manner. Instead of decompressing the orbit into the adjacent sinuses by removing bone, with supraorbital advancement, the walls of the orbit could be displaced forward to expand the orbital volume. The bones of the orbit were osteotomized and moved forward and downward en bloc, filling any contour abnormality with onlay bone grafts (Fig 1). If necessary, dental relationships were preserved by performing a compensatory osteotomy of the
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Fig 1. Lefort III osteotomy with midfacial advancement described for severe exophthalmos. Arrow indicates direction of displacement of midface. Hatched lines indicate area of contour bone grafts. (Reprinted with permission from Tessier P. Expansion of the orbital cavity. In: Tessier P, ed. Plastic Surgery of the Orbit and Eyelids. New York: Masson, 1981; 107-17.)
maxilla. 28 - 30 This procedure requires a craniotomy (and the combined efforts of a craniofacial surgeon and a neurosurgeon) and prolonged intermaxillary fixation and was reserved for severe cases. While we have not had occasion to see or review any material with regard to the results of this procedure in Graves' orbitopathy, results in the craniofaciostenoses indicate little bone resorption and favorable alterations in facial morphology with long-term follow-up through adolescence and into adulthood. 31 - 33 In more moderate cases of orbitopathy, Tessier advocated orbital expansion by lowering the orbital floor, by valgus osteotomy of the zygoma, and by mesial displacement of the lamina papyracea, alone or in combination depending on the degree of exophthalmos. To perform the valgus osteotomy, a bicoronal approach to the orbits was employed. Saw cuts were made in the zygoma and frontal bone along the lateral orbital wall, and the zygomatic arch was greenstick fractured so as to rotate the malar complex and lateral orbital wall outward (Fig 2)_2 8- 30 A similar approach was described by Wolfe that did not require a greenstick fracture and has produced good results. 34- 36 Wolfe also emphasized that the periorbita should not be violated to avoid postoperative motility
Fig 2. Top, Tessier's orbital expansion for dysthyroid orbitopathy. Dotted lines outline horizontal and vertical osteotomy sites (Reprinted with permission from Tessier P. Expansion of the orbital cavity. In: Tessier P, ed. Plastic Surgery of the Orbit and Eyelids. New York: Masson, 1981; 107-17.) Bottom, valgus osteotomy of malar bone. Bone wired in place, rotated outward and posteriorly (arrow). Ethmoidal infracture is shown. Hatched lines indicate lowered orbital floor. Dots indicate onlay bone grafts. Arrow indicates area of greenstick fracture. (Reprinted with permission from Tessier P. Expansion of the orbital cavity. In: Tessier P, ed. Plastic Surgery of the Orbit and Eyelids. New York: Masson, 1981; 107-17.)
problems. 35 Perhaps the reluctance of patients to undergo a "craniofacial" procedure, or perhaps established referral patterns of dysthyroid patients to ophthalmic surgeons who are more familiar with decompressive techniques, accounts for the fact that these techniques do not enjoy wider acceptance. We describe a modified technique of three-wall decompression (lateral wall, medial wall, and floor) that can be used by the experienced orbital surgeon. It is a modification of Tessier's valgus osteotomy that is done in conjunction with a three-wall orbital decompression. The lateral wall of the orbit is removed as in conventional lateral orbitotomy and replaced in a forward and outward position. While the lateral wall is out, antralethmoidal decompression is accomplished. We believe that posterior 1359
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orbital decompression into the ethmoidal sinuses is essential to the appropriate surgical management of dysthyroid optic neuropathy. However, moving the lateral wall outward and anteriorly increases the amount of decompression that can be attained laterally by increasing the horizontal and sagittal length of the bony orbit and, hence, increases the bony orbital volume. It also provides a potential space behind the advanced rim into which lateral orbital decompression can occur. Removing the lateral wall before antralethmoidal decompression facilitates surgery in the medial orbital apex, because the orbital contents can be mobilized laterally, thus aiding visualization. Our preliminary results in nine patients suggest that facial morphology is enhanced. In contradistinction to other methods of orbital decompression in which upper eyelid retraction often gets worse, orbital advancement appears to lessen the degree of lid retraction associated with orbitopathy and facilitates (and in some cases, obviates) the need for lid retraction surgery.
TECHNIQUE With the patient under general endotracheal anesthesia, the lower eyelid and lateral canthal area are infiltrated with bupivacaine (Marcaine) 0.5% with 1 to 200,000 adrenaline solution. The nose is packed with oxymetazoline (Afrin, 0.05%) on 3" X 'h'' neurosurgical cottonoids. The patient is prepared and draped in the usual sterile manner. A protective corneoscleral shell is placed. A broad-spectrum antibiotic is infused. A 3-cm horizontal incision is made from the lateral canthal angle (Fig 3). Anteriorly, a lateral canthotomy and inferior limb cantholysis are performed; posteriorly, the incision is deepened through orbicularis using a needle tip monopolar cutting cautery. A skin muscle flap is raised posterior to the orbital rim both superiorly and inferiorly to expose the zygomatic periosteum and the superficial temporalis fascia. Wide undermining is necessary to obtain good exposure of the superior and inferior portion of the lateral orbital wall. The zygomatic periosteum is incised 3 mm lateral to the orbital entrance site from above the frontozygomatic suture to the level of the orbital floor. Two 2.5-cm relaxing incisions are made in periosteum, one horizontally along the superior border of the zygomatic arch and the other at the junction ofthe temporalis fascia and the epicranium at the superior temporal crest. The temporalis muscle is reflected from its insertion at the crest and out of the temporalis fossa using a periosteal elevator. Bone wax may be necessary to control bleeding through venous dipoloe. The elevator is then used to reflect periorbita from the lateral wall of the orbit and for approximately 1 em along the roof and floor. At this point, horizontal osteotomies with an oscillating saw are made in the lateral wall, from the floor of the orbit at the level of the superior border of the zygomatic arch, and at the zygomatic arch above the frontozygomatic suture within the lacrimal fossa (Fig 4, top center and top right). In this manner, between 3 and 4 em ofbone is routinely removed. 1360
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The bone is placed in a blood-soaked sponge. A diamond drill is used to remove bone behind the sphenozygomatic suture until the bleeding marrow of the greater wing of the sphenoid is observed (Fig 5). Alternatively, doubleaction rongeurs can be used. An inferior limb cantholysis is performed and the lower eyelid is distracted downward using two Blair retractors. An incision is made at the lower border of the tarsus from the lateral cantholysis to a level immediately beneath the inferior punctum using a needle point monopolar cutting cautery. The incision transects the lower eyelid retractors and orbital septum and exposes a plane for a skin muscle flap that is raised to the orbital floor using a combination of cutting cautery and blunt cotton-tip applicator dissection. The Blair retractors are then replaced with a large vein retractor, and the lid is vigorously retracted. With a finger pressed on the lower eyelid retractors, the arcus marginalis and the floor of the orbit are readily visualized and palpated. The periosteum of the orbital floor is incised with the cutting cautery from the inferior osteotomy site as in blowout fracture repair and the periosteum of the floor of the orbit is dissected from the floor using a Freer elevator. Soule retractors are placed in the orbit. With a hemostat, the bony orbital floor is punctured medial to the infraorbital groove. Floor bone is then removed posterior to the midaxis of the globe with a Kerrison rongeur or a pituitary forceps as far as the posterior wall of the antrum (Fig 6). The bone lateral to the groove is likewise punctured with a hemostat, avoiding the inferior orbital fissure. The bone surrounding the neurovascular bundle is then separated and removed with 0.3 mm forceps such that the neurovascular bundle is free within the maxillary sinus. With the floor and lateral wall removed, the orbital contents including the globe can be mobilized laterally with Soule retractors to obtain excellent visualization of the medial wall and medial orbital apex (Fig 7). The periosteum of the medial wall is freed to the level of the ethmoidal foraminae, and bone and ethmoidal sinuses are exenterated with Wilde forceps until the thickened bone of the optic canal is reached. The inferior, medial, and posterolateral periorbita is then incised with an arachnoid knife and partially removed. It is essential to leave the anterolateral periorbita intact so that the lower lid can be reattached when the canthus is reformed at the time of closure. Orbital fat should freely prolapse into the medial ethmoids, the antrum, and into the temporalis fossa. If desired, anterior orbital fat may be resected, cauterizing any bleeders with bipolar cautery. At this time, the lateral wall advancement is accomplished. The lateral wall bone is now replaced in its normal anatomic position (Fig 4, top right). It is then advanced approximately 4 mm anteriorly and 2 mm laterally into its osteotomized position (Fig 4). The bone is then rigidly fixated with two Synthes four-hole orbital reconstruction miniplates (Fig 8). This is done by bending soft metallic templates to conform to the osteotomy, followed by bending the titanium miniplates to match the templates. Drill holes are placed in the frontal bone and the zygomatic bone followed by drill holes in the free bone. This
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Fig 3. Top left, incision for lateral portion of orbital advancement, 3 em horizontally from the lateral canthus. Fig 4. Top center, site of bony horizontal osteotomies. Top right, case 3. Site of bony horizontal osteotomies. Bottom left, vectors of rotation. Bone is advanced fmward approximately 3 mm, then 2 mm laterally. Slight external and outward rotation is applied (see also Fig 3). Bottom right, case 3. Bone in osteotomized position, advanced approximately 3 mm forward and 2 mm laterally.
free bone is fixated in the advanced position with a Synthes bone holding clamp, and soft tissues are protected with the Synthes soft tissue guard. Then, 1.5 mm self-tapping titanium screws are passed, and the bone is rigidly fixated in the osteotomized position (Fig 8). We feel that the rim of the replaced bone that projects anteriorly might be palpable, or even noticed by the patient. For this reason, methylmethacrylate bone cement (Cranioplast) is applied to the advanced bone edge, sculpted, allowed to set, and then contoured further with a diamond drill (Fig 9). Alternatively, we have used bone removed during the decompression as a free onlay bone graft. The subcutaneous tissues are then closed in the following fashion: two 7-0 Vicryl sutures are passed from the lower lid retractors to the lower border of the tarsus and tied loosely in buried interrupted fashion. A lateral canthopexy is now performed. A 6-0 proline suture is placed through the lateral border of the lower tarsus and sutured
to the periosteum inside the orbital rim with a horizontal mattress suture. The lateral canthal angle is reformed with a 6-0 silk suture. The temporalis fascia is reattached with a 4-0 chromic suture to the epicranium at the superior temporal crest. The periorbita is then sutured to the zygomatic periosteum and its attached temporalis fascia with 4-0 chromic sutures. Because the lateral wall of the orbit has been advanced anteriorly, it is difficult not to suture this aspect of the wound under tension, and it is often helpful to use interrupted vertical mattress sutures. A potential space is created behind the advanced and laterally displaced rim that is devoid oftemporalis and is bordered by the zygomatic periosteum on stretch into which the orbital fat can prolapse (Fig 10). A subcutaneous closure is accomplished with 5-0 chromic sutures, the skin is closed with a running 6-0 proline suture, and the wound is dressed with Steristrips. Ten milligrams of intravenous dexamethasone is infused. No patches are applied. The patient is kept at bedrest with 1361
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the head of the bed elevated 30°, and receives iced saline compresses, intravenous and topical antibiotics, and intravenous dexamethasone in tapering doses for 2 days. The patient is discharged on the third postoperative day.
In all patients, lower lid retraction decreased postoperatively by an average of 2 mm. Upper lid scleral show also decreased by an average of 2 mm (range, 0-4 mm). No ptosis was produced with the technique described. In cases where upper lid retraction changed little with the procedure, a change in the amount of retraction in the area temporal to the limbus was nonetheless observed, and consequently, eyelid appearance was enhanced (Fig 12). A single patient developed recurrent upper eyelid retraction 13 months postoperatively, after an initial drop in the lid of 5 mm, that was possibly due to continued progression of her orbitopathy. Five patients had significant diplopia preoperatively: all of them had diplopia postoperatively, and in three, the decompression appeared to worsen the strabismus. All eight orbits with optic neuropathy had improved acuities postdecompression. No postoperative radiation or longterm steroids were required. Infraorbital hypesthesia was observed in two orbits; it has persisted beyond a year in one of these. No lid mal positions have ensued from advancing the lateral wall forward. Representative preoperative and postoperative photographs are presented in Figures 11 and 12. In three patients for whom predecompression planning had included the need for upper and lower lid retractor recession, a lessening of lid retraction occurred such that no lid retraction surgery was required. In two additional patients, instead of retractor recession, blepharoplasty with removal of fat corrected the residual deformity.
PATIENTS AND METHODS
DISCUSSION
Nine patients from the Orbital and Oculoplastic Service at the University of Pennsylvania and the University of Nebraska were decompressed and advanced with the technique described. Three of these patients underwent bilateral decompression and lateral rim advancement. All patients received a full ophthalmic evaluation that included a visual field and computed tomography scan. All preoperative and postoperative exophthalmometry measurements were done with the Naugle exophthalmometer, which is not based at the orbital rims. 37 Indications for decompression were optic neuropathy in five patients (eight orbits), threatened corneal perforation from malignant exophthalmos in two patients (two orbits), exposure keratopathy in one patient, and cosmesis purposes in one patient.
The traditional approach to orbital decompression has been to remove one or more walls of the orbit, allowing the orbital contents to herniate into the potential space created by the surgeon. A technique for removal of every wall of the orbit has been devised. Two-, three-, and fourwall decompressions can be accomplished in combination and have been reported with good results and with varied rates and types of complications. 1•6 •18 •20- 25 In a recent survey of orbital surgeons, 75% of decompressions were performed as two-wall decompressions with removal of the floor and medial wall. These procedures were performed either via the translid route or via the transantral route. 26 This same review concluded that the transantral approach provided the best "final visual acuity" due to the better apical visualization and more complete optic nerve decompression, and was therefore preferred for cases of compressive optic neuropathy. 26 Although widely accepted, the antralethmoidal decompression is not without its problems. There is a significant risk of postoperative strabismus, and this is especially true in transantral decompression. 26 Reasons for the increase in motility problems are not clear; however, it is our impression that surgery in the medial orbital apex may disturb the muscles at their insertions, particularly the medial rectus. We currently attempt not to remove the small ridge of floor bone adjacent to the optic strut
Fig 5. Temporal decompression along sphenoid with diamond burr. Alternatively. bone biting rongeurs can be used.
RESULTS The three-wall decompression with lateral orbital advancement has been performed on a total of 12 orbits in nine patients. The mean amount of decompression was 6.6 mm (range, 3-10 mm). As in most other studies, the greater the initial proptosis, the greater the amount of final decompression. 1362
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Fig 6. Top left, transconjunctival approach to orbit with swinging lower eyelid flap and direct view of orbital floor as in blowout fracture repair. Fig 7. Top right, mobilization ofthe orbit laterally into the defect in the lateral wall exposes the apex and encourages direct visualization of apical structures. Hatched lines, area decompressed. Fig 8. Center left, case 3. Bone fixated in osteotomized position with Synthes titanium miniplates. Center right, bone fixated in osteotomized position, outward and forward, with Synthes titanium mini plates. Fig 9. Bottom left, edge of advanced bone contoured with Cranioplast bone cement. Bone dust or onlay fragments may also be used if anchored firmly under periosteum. Bottom right, edge of advanced bone contoured with Cranioplast (blue hatched lines: area contoured with Cranioplast).
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Fig 10. Left, postoperative computed tomographic scan demonstrates potential space behind the advanced lateral orbital rim (arrow). Right, potential space behind advanced lateral wall (arrow).
so as to avoid this complication. Because of the significant risk of postoperative strabismus, Leone et al recently sought alternatives to the antral ethmoidal decompression and described a medial and lateral approach to the orbit that avoids the floor entirely with no postoperative impairments in motility in their series. 20 Originally described by Kronlein, 38 the single-wall lateral decompression is the oldest decompressive procedure and is familiar to most ophthalmologists. It has been modified by Guyton, Berke, Moran, Long and Ellis, and recently by Trokel and Cooper. 8 •10- 12 •27 Variations on the original procedure include incisions into the temporalis muscle, excision of temporalis muscle, and removal of the orbital rim. 8 •10- 12 •27 However, the procedure has fallen out of favor for a variety of reasons: large amounts of decompression are not possible, the bulky temporalis muscle often expands and blocks any herniation of orbital tissue into the temporalis fossa, the procedure may produce its own cosmetic deformity, and postoperative ex-
ophthalmometry readings based at the orbital rim become impossible. 21 •27 •37 Finally, work done in dried skulls has suggested that little volume can be added to the orbit by expanding it laterally. 39 •40 Several factors, however, militate against dismissing the lateral wall approach altogether. Removal of the lateral wall is technically straightforward and allows easy access to the orbit posterior to the midaxis of the globe. An experimental study in cadavers showed that removing the lateral wall of the orbit provided as much proptosis reduction as removal of the medial wall. 41 Additionally, removing the lateral wall before performing medial and inferior decompression enhances visualization of the orbital apex. With the bone removed, the orbital contents can be mobilized in the direction of the temporalis fossa without the interference of the proptotic globe pressing against the lateral orbital rim. This lateral displacement of the orbit is similar to a reported approach for access to the medial posterior intraconal space in which medial
Fig 11. Case 3. Top left, preoperative Naugle Hertel reading, 23 mm. Top right, 3 months postoperative decompression and lateral wall advancement in both eyes. Naugle Hertel reading, 16 mm. Bottom left, preoperative photograph. Bottom right, 3 months postoperative photograph.
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Fig 12. Case 9. Left. preoperative Naugle Hertel reading, 23.5 mm. Right, 3 months postoperative after orbital decompression and lateral wall advancement to the left eye only. Naugle Hertel reading, 19.5 mm. Notice unilateral decrease in temporal upper eyelid retraction on advanced side. Fissure size decreased by 0.5 mm. There was no change in lower eyelid position.
intraconal surgery is preceded by a lateral wall "outfracturing."42 Superior visualization of the orbital apex is obtained, permitting the surgeon an enhanced view of the ethmoids, and access to the ethmoidal foraminae and the medial and inferior walls of the optic canal. In all patients who required decompression for compressive optic neuropathy (eight orbits, five patients), the procedure yielded an improved final visual acuity. While the actual number of cases is small, it nonetheless suggests that this technical addition to the routine translid procedure may be as effective in improving "final visual acuity" as is the most commonly used procedure for dysthyroid optic neuropathy, the Ogura procedure.Z6 We believe that posterior orbital apical decompression is essential for good visual outcome in patients with dysthyroid optic neuropathy, and we have routinely performed decompression in conjunction with advancement; we are not confident that a lateral wall advancement alone would suffice to correct a posterior compressive optic neuropathy. We feel that lateral wall advancement enjoys several technical and aesthetic advantages over the conventional techniques of three-wall decompression. A sliding osteotomy of the lateral orbital wall displaces the lateral orbital wall outward and forward, creates additional entrance width to the orbit, and expands the orbital sagittal length. The bony orbital confines are enlarged. As in valgus osteotomy, or en bloc advancement, the size of the bony orbit is expanded, the relationship between the bony and soft tissue orbit becomes more appropriate, and exophthalmos is thereby reduced. While other authors have noted that the temporalis muscle may interfere with the expansion of orbital soft tissue in lateral orbital decompression,Z 7 with the lateral wall advancement technique, a space is created in the temporalis fossa into which orbital soft tissue can prolapse. When the lateral wall is advanced outward and forward, the temporalis fascia and muscle are placed on stretch and also are displaced outward and forward. This potential space behind the advanced rim can be observed at the time of surgery (Fig 10). 1366
Finally, in contrast to other approaches to orbital decompression in which the amount of upper eyelid retraction is usually increased following the procedure, 26 it appears that upper and lower eyelid position are more favorably affected with the sliding osteotomy approach. In all of our cases, lower eyelid position was improved by orbital advancement. The upper lid also appeared to be more favorably affected. In all but one case, upper eyelid retraction improved. The improvement either took the form of a more normal lid contour with a lessening of temporal eyelid retraction or an actual change in upper eyelid position. In three cases, the lid retraction was reduced to the point that no additional lid surgery was required; in two other patients, additional appearance enhancement was attained with blepharoplasty alone. We have several postulates for why orbital advancement may reduce eyelid retraction. ( 1) A lateral canthopexy is performed at the time of closure of the incisions. Lower lid position may be slightly improved because the lower lid is tightened and raised laterally at the lateral canthus. (2) With lateral wall advancement, the lateral retinaculum is also advanced forward with its attached Lockwood's and Whitnall's ligaments. Upper and lower eyelid retraction may be reduced because the lids and their anterior attachment points are also pushed forward over the decompressed globe. (3) Sliding the lateral wall of the orbit laterally and anchoring the lateral canthus and its attachments to the displaced bone tightens the lids horizontally and hence reduces the amount of their curvature, and may lessen lid retraction. Stretching normal or retracted upper and lower eyelids laterally can be seen to reduce the size of the vertical fissure (Fig 13). Our technique may also offer several advantages over the described craniofacial approaches to the orbit. In contrast to the techniques described by Tessier and modified by Wolfe, a bicoronal approach is not necessary.28-30·34-36 We have found that patient acceptance of lid incisions for orbital surgery has been greater than that for ear-to-ear incisions. A lid incision is easily and cos-
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Fig 13. Left, patient with 2 mm of upper eyelid retraction. Right, manual distraction of eyelid laterally produces ptosis. Lateral displacement of lateral canthus may account, in part, for lessening of eyelid retraction after lateral wall osteotomy.
metically concealed, and usually heals with less associated facial swelling. Our technique is also more familiar to most orbital surgeons. A segment of zygomatic bone is osteotomized rather than the entire lateral malar complex or the entire orbital roof as in the craniofacial approaches. We feel that removal of the lateral wall alone without the malar eminence suffices to correct the problem. In Tessier's valgus osteotomy technique, a greenstick fracture is created in the zygomatic arch that could potentially injure the facial nerve. 28- 30 In both Tessier and Wolfe's described techniques, vertical osteotomies are required. 28- 30·34- 36 None of these surgical maneuvers is required with our technique. Horizontal osteotomies of the lateral wall are routine in the conventional lateral orbitotomy procedure. In all of our cases, we moved the lateral wall forward 4 mm and laterally 2 mm. To date, we have not seen an overcorrection with the technique. We feel that even with larger amounts of proptosis, a wider or more anteriorly placed osteosynthesis might produce a cosmetic deformity, and possibly enophthalmos as well, and we have titrated our decompression to fit the degree of proptosis and not the osteotomy. It is a matter for future research as to whether these numbers are indeed optimum. Our indications for lateral wall advancement are evolving. We have used the technique as an adjunct to orbital decompression and for indications for which a routine orbital decompression would be performed, i.e., dysthyroid optic neuropathy, exposure keratopathy, corneal ulcer, or cosmetic reasons. In the latter category, we routinely discuss the potential surgical management of orbitopathy along with risks and come to a decision influenced by the degree of disfigurement and by the patient's willingness to accept the higher risk inherent with decompression than with lid surgery alone. If decompression is selected as a surgical option, we perform lateral wall advancement routinely in conjunction with the orbital decompression. While it would be exciting to speculate that anterolateral advancement of the lateral orbital wall is an excellent technique for enhancing facial ap-
pearance in patients with the dysmorphic appearance of Graves' orbitopathy, we do not feel that a lateral orbitotomy and an advancement osteotomy are routinely indicated in patients with eyelid retraction. Other less involved techniques can be performed on an outpatient basis under local anesthesia with less attendant risks. t-s Our procedure demands the use of craniomaxillofacial miniplates. Compression plates have been used with great effectiveness in the treatment of mandibular fractures,43·44 in advancement of the maxilla, in orthognathic surgery, 45 -48 and in the treatment of fractures and deformities of the facial skeleton. 44·49 It is vital that the osteotomized bone of the lateral wall be kept in rigid fixation in its new position so that osteosynthesis can occur. In the absence of rigid skeletal fixation, we feel that with our procedure, the action of the temporalis muscle would tend to countermand the effectiveness of an osteotomy performed with point-to-point wire fixation, and the bone of the lateral orbital rim could be pulled back into the normal anatomic position. Furthermore, miniplates allow the surgeon to advance the bone with a more precise spatial orientation than could be obtained with wire alone. The plates are made of titanium and are made by AO/ASIF (Synthes Maxillofacial, Paoli, PA). They are inert, corrosion resistant, and biocompatible, and they do not need to be removed. Courses are given throughout the country to familiarize the surgeon with their use. While we have had occasion to use other systems (the Luhr miniplate system, Howemedica, Rutherford, NJ; the Wurzberg system, Walter Lorenz, Jacksonville, FL), our experience with them is limited to two of the described cases. To date, we have had no complications with any of the available orbital reconstruction plates. The most timeconsuming and tedious portion of the procedure is bending the plate to fit the osteotomized bone because only a perfect angulation of the plate will fixate the bone in the desired position. Unlike wire fixation where the bone may recontour with time and the positioning of drill holes is not critical, with rigid fixation, the position of the bone after the self-tapping screws are placed represents the final 1367
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position, and there is little margin for error (Fig 8). Methylmethacrylate bone cement (Cranioplast) is well described for contouring of bone in the orthopedic, craniofacial, and neurosurgical literature. 50- 54 It has also been used as an orbital volume substitute. 55 We use Cranioplast as a means of creating a smooth, anteriorly displaced orbital rim. To date, we have had no complications from its use. In our last two cases, influenced by our craniofacial surgical colleague, we have used autogenous bone harvested from the lateral wall decompression as an onlay contouring free graft fixated under periosteum, but we do not have enough follow-up data to make a comment regarding its long-term efficacy. While our series of cases is small, we are nonetheless encouraged by the significant advantages offered by lateral orbital rim advancement and expansion when done in conjunction with antralethmoidal decompression, both from a visualization of the orbital apex and a cosmetic standpoint. While postoperative motility disturbance remains a problem, as it has in other antralethmoidal decompression series, a recent article suggesting that postoperative morbidity can be significantly decreased with a combined medial and lateral approach to the orbit that leaves the floor of the orbit intact is intriguing. 20 It may well be that two-wall decompression with lateral wall decompression and advancement in combination with a medial approach will prove to be our future technique of choice.
REFERENCES 1. Linberg JV, Anderson RL. Transorbital decompression: indications and results. Arch Ophthalmol1981; 99:113-9. 2. Hurwitz JJ, Birt D. An individualized approach to orbital decompression in Graves' ophthalmopathy. Arch Ophthalmol1985; 103:660-5. 3. Kennerdell JS, Maroon JC, Buerger GF. Comprehensive surgical management of proptosis in dysthyroid orbitopathy. Orbit 1987; 6: 153-79. 4. Shorr N, Seiff SR. The four stages of surgical rehabilitation of the patient with dysthyroid ophthalmopathy. Ophthalmology 1986; 93: 476-83. 5. Frueh BR. Graves' eye disease. In: Waltman SR, Keates RH, Hoyt CS, et al, eds. Surgery of the Eye. Vol. 2. New York: Churchill Livingstone, 1988; 719-32. 6. Nafziger HC. Progressive exophthalmos following thyroidectomy: its pathology and treatment. Ann Surg 1931; 94:582-6. 7. Sewall EC. Operative control of progressive exophthalmos. Arch Otolaryngol 1936; 24:621-4. 8. Guyton JS. Decompression of the orbit. Surgery 1946; 19:790-809. 9. Hirsch 0. Surgical decompression of malignant exophthalmos. Arch Otolaryngol 1950; 51:325-34. 10. Berke RN. A modified Kronlein operation. Trans Am Ophthalmol Soc 1953; 51:193-231. 11. Moran RE. The correction of exophthalmos and levator spasm. Plast Reconstr Surg 1956; 18:411-26. 12. Long JC, Ellis GO. Temporal decompression of the orbit for thyroid exophthalmos. Am J Ophthalmol1966; 62:1089-98. 13. Ogura JH. Transantral orbital decompression for progressive exophthalmos: a follow-up of 54 cases. Med Clin North Am 1968; 52:399407.
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14. Surgical approach to the ophthalmopathy of Graves' disease. JAMA 1971; 216:1627-31. 15. Ogura JH, Thawley SE. Orbital decompression of exophthalmos. Otolaryngol Clin North Am 1980; 13(1):29-38. 16. Lanier V Jr. The surgical treatment of exophthalmos. Plast Reconstr Surg 1975; 55:56-64. 17. Calcaterra TC. Paranasal sinus decompression of the orbit in Graves' disease. Ophthalmic Surg 1977; 8(2):80-4. 18. Leone CR Jr, Bajandas FJ. Inferior orbital decompression for thyroid ophthalmopathy. Arch Ophthalmol1980; 98:890-2. 19. Leone CR Jr. The management of ophthalmic Graves' disease. Ophthalmology 1984; 91:770-9. 20. Leone CR Jr, Piest KL, Newman RJ. Medial and lateral wall decompression for thyroid ophthalmopathy. Am J Ophthalmol 1989; 108:160-6. 21. Baylis HI, Call B, Shibata CS. The transantral orbital decompression (Ogura technique) as performed by the ophthalmologist: a series of 24 patients. Ophthalmology 1980; 87:1005-12. 22. Small RG, Meiring NL. A combined orbital and antral approach to surgical decompression of the orbit. Ophthalmology 1981; 88:542-7. 23. Anderson RL, Linberg JV. Transorbital approach to decompression in Graves' disease. Arch Ophthalmol1981; 99:120-4. 24. McCord CD Jr. Orbital decompression for Graves' disease: exposure through lateral canthal and inferior fornix incision. Ophthalmology 1981; 88:533-41. 25. Kennerdell JS, Maroon JC. An orbital decompression for severe dysthyroid exophthalmos. Ophthalmology 1982; 89:467-72. 26. McCord CD Jr. Current trends in orbital decompression. Ophthalmology 1985; 92:21-33. 27. Trokel SL, Cooper WC. Orbital decompression: effect on motility and globe position. Ophthalmology 1979; 86:2064-70. 28. Tessier P. Expansion chirurgicale de l'orbite. Ann Chir Plast 1969; 14: 207-14. 29. Tessier P. Total osteotomy of the middle third of the face for faciostenosis or for sequelae of Le Fort Ill fractures. Plast Reconstr Surg 1971; 48:533-41. 30. Tessier P. Expansion of the orbital cavity. In: Tessier P, ed. Plastic Surgery of the Orbit and Eyelids. New York: Masson, 1981; 107-17. 31. Kaban LB, Conover M, Mulliken JB. Midface position after Le Fort Ill advancement: a long-term follow-up study. Cleft Palate J 1986; 23(Suppl 1):75-7. 32. Ousterhout OK, Vargervik K. Aesthetic improvement resulting from craniofacial surgery in craniosynostosis syndromes. J Craniomaxillofac Surg 1987; 15:189-97. 33. Whitaker LA, Bartlett SP. The craniofacial dysostoses: guidelines for management of symmetric and asymmetric disease. Clin Plast Surg 1987; 14:73-81. 34. Wolfe SA. Surgical treatment of exophthalmos and enophthalmos. Ann Ophthalmol1981; 13:995-1002. 35. Wolfe SA. Modified three-wall orbital expansion to correct persistent exophthalmos or exorbitism. Plast Reconstr Surg 1979; 64:448-55. 36. Wolfe SA, Hemmy D. How much does moving the lateral wall help in expanding the orbit? Ophthalmic Plast Reconstr Surg 1988; 4:111-4. 37. Naugle TC. Methodology and measurement with lateral orbitotomy. In: Henkes HE. Metabolic Eye Diseases: Proceedings of the Vllth Congress of the European Society of Ophthalmology. Helsinki: Patrons Association of the European Ophthalmological Society, 1985; 54950. 38. Kronlein RU. Zur pathologie und operaten Behandlung der Dermoidcysten der Orbita. Beitr Klin Chir 1888; 4:149-63. 39. Stabile JR, Trokel SM. Increase in orbital volume obtained by decompression in dried skulls. Am J Ophthalmol1983; 95:327-31. 40. McCord CD Jr, Putnam JR, Ugland D. Pressure-volume orbital mea-
WULC et al
41. 42. 43.
44.
45.
46.
47.
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surement comparing decompression approaches. Ophthalmic Plast Reconstr Surg 1985; 1:55-63. Pearl RM. Surgical management of volumetric changes in the bony orbit. Plast Surg Forum, Vll11985; 45:105-106. McCord CD Jr. A combined lateral and medial orbitotomy for exposure of optic nerve and orbital apex. Ophthalmic Surg 1978; 9(3):58-66. Spiess! B. Rigid internal fixation after sagittal split osteotomy of the ascending ramus. In: Spiess! B, ed. New Concepts in Maxillofacial Bone Surgery. Berlin: Springer-Verlag, 1976:115. Texhammar R, Schmoker R. Stable Internal Fixation in Maxillofacial Bone Surgery: A Manual for Operating Room Personnel. Berlin: Springer-Verlag, 1984. Luyk NH, Ward-Booth RP. The stability of Le Fort II advancement osteotomies using bone plates without bone grafts. J Craniomaxillofac Surg 1985; 13:250-3. Harsha BC, Terry BC. Stabilization of Le Fort I osteotomies utilizing small bone plates. lnt J Adult Orthod Orthognathic Surg 1986; 1:6977. Rosen HM. Miniplate fixation of LeFort I osteotomies. Plast Reconstr Surg 1986; 78:748-55.
48. Holtje WJ. Midfacial osteotomies in patients with cleft lip, alveolus and palate. Aust N Z J Surg; 1987; 57(2):89-99. 49. Beals SP, Munro IR. The use of miniplates in craniomaxillofacial surgery. Plast Reconstr Surg 1987; 79:33-8. 50. Volz RG, Kloss J, Peltier LF. The use of methylmethacrylate as a temporary spacer following en bloc resection of the distal femur: a case report. Clin Orthop 1980; 147:185-7. 51. Dorr LD. Treatment of hip fractures in elderly and senile patients. Orthop Clin North Am 1981; 12:153-63. 52. Pochon JP. The repair of congenital and acquired skull defects in childhood. J Pediatr Surg 1982; 17:31-6. 53. Ousterhout DK, BakerS, Zlotolow I. Methylmethacrylate onlay implants in the treatment of forehead deformities secondary to craniosynostosis. J Maxillofac Surg 1980; 8:228-33. 54. Steimie R, Bourghli A, Jacquet G, et al. Cranioplasty with acrylic methyl methacrylate resin: modified procedure-technical note. Zentrabl Neurochir 1986; 47:24-7. 55. Wilkins RB, Kulwin DR, McCord CD Jr, Tanenbaum M. Skin and tissue techniques. In: McCord CD, Tanenbaum M, eds. Oculoplastic Surgery, 2nd ed. New York: Raven, 1987; 37.
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