Transection of inferior orbital fissure contents for improved access and visibility in orbital surgery.

TECHNICAL STRATEGY

Transection of Inferior Orbital Fissure Contents for Improved Access and Visibility in Orbital Surgery Sophie Ricketts, BMedSci, MBBS,* Hall F. Chew, MD, FRCSC,Þ Ian R. P. Sunderland, MD, FRCSC,þ Alex Kiss, PhD,§ and Jeffrey A. Fialkov, MD, MSc* Background: Selective inferior orbital fissure (IOF) content transection for the purpose of surgical access to the posterior orbital floor is a technique that facilitates visualization of the posterior bony ledges of traumatic orbital floor defects. It also has potential advantages in achieving stable placement of reconstructive materials. Although not new, the surgical technique has not yet been described, and the morbidity of the technique has not been quantified. This article describes the procedure and assesses the morbidity specific to the division of related neural structures. Methods: The technique and surgical anatomy are described and illustrated with intraoperative photographs. Postoperative assessment of neural structures relevant to the division of IOF contents is performed. These values are compared with the nonoperated side to evaluate the morbidity of the technique. Results: The technique, which is consistently used by the senior author in the repair of orbital floor defects with very small posterior ledges or which extend to and involve the IOF, facilitates better visualization of the posterior ledge and posterolateral ledge in such cases. Surgical outcomes including facial sensation and lacrimal function on the operated side remain within the reference range and are not significantly different when compared with the contralateral nonoperated side. Conclusions: Selective IOF transection aids in the direct visualization of the posterior bony ledges in the repair of posterior orbital floor defects. It therefore may facilitate the placement of reconstructive materials on bony ledges circumferentially, providing stable reconstruction, potentially reducing implant-related complications without causing increased morbidity.

From the *Division of Plastic Surgery and †Department of Ophthalmology & Vision Sciences, University of Toronto, Sunnybrook Health Sciences Centre, Toronto, Ontario; ‡Clinical Assistant Professor, Division of Plastic Surgery, University of Saskatchewan, Saskatoon, Saskatchewan; and §Department of Research Design and Biostatistics, Sunnybrook Research Institute, Toronto, Ontario, Canada. Received September 23, 2013. Accepted for publication October 22, 2013. Address correspondence and reprint requests to Jeffrey A. Fialkov, MD, MSc, FRCSC, Division of Plastic Surgery, Sunnybrook Health Sciences, 2075 Bayview Ave, Suite M1-516, Toronto, Ontario, Canada M4N 3M5; E-mail: [email protected] Author contributions: S.R.: primary author of manuscript; H.F.C.: ophthalmological assessment; J.A.F.: senior author, secondary author of manuscript, literature review; I.R.P.S.: secondary author, contributed to manuscript, literature review, photographs; A.K.: statistical analysis of data. The authors report no conflicts of interest. Copyright * 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000000489

The Journal of Craniofacial Surgery

Key Words: Orbital fracture, inferior orbital fissure, orbital anatomy, orbital floor reconstruction, facial sensation (J Craniofac Surg 2014;25: 557Y562)

O

rbital floor reconstruction for fractures secondary to trauma, although conceptually straightforward, sees a relatively high incidence of complications. Common complications and their incidences include enophthalmos (1.5%Y43.5%), persistent diplopia (1.2%Y32.1%), and dysesthesia in the malar region (50%Y100%).1 It is a technically demanding operation requiring meticulous technique. Clear visualization of the bony ledges upon which to stabilize the reconstructive material is requisite for accurate, anatomic restoration of orbital floor anatomy to reduce these postoperative complications. Additional implant-related complications may include hyperglobus and/or proptosis, migration or extrusion of the implant, inferior rectus muscle entrapment, or even blindness.2,3 One of the critical technical principles relating to implant placement, and therefore effective repair of orbital floor defects, is the correction of the posterior most aspect of the defect, which requires stabilizing the reconstructive material on posterior bony ledges.4Y8 Access to this posterior bony ledge as well as the posterolateral margin of the floor defect can be difficult and risky.4,5,9 Posterior orbital structures at risk during dissection and traumatic retraction include the contents of the superior orbital fissure and the optic nerve.4 The posterior-most limit of the orbital floor defect generally lies medial to the infraorbital sulcus (groove) at its junction with the inferior orbital fissure (IOF) (Fig. 1). The maxilla is relatively thin in this area and therefore often fractured, unstable, or absent. The thicker orbital process of the palatine bone, normally confluent with the maxillary portion of the floor anteriorly, often remains intact and constitutes the remaining posterior ledge. Immediately lateral to the posterior ledge and tethering the orbital soft tissue contents, are the components of the IOF as they exit the IOF (Figs. 2A, B). Visualization of the posterior ledge is therefore limited by the distance that the IOF contents can be retracted cephalically. Transection of the contents of the IOF therefore facilitates the upward (cephalic) retraction of the orbital soft tissues, facilitating better visualization of and access to the posterior orbit medial to the junction of the infraorbital sulcus and IOF, that is, the posterior ledge. Transecting the IOF contents for improved surgical access to the posterior orbit has previously been suggested.4 However, the surgical anatomy, technical details, advantages, and associated morbidity are not well described. This article describes the relevant surgical anatomy and a technique to safely and selectively transect the contents of the IOF so as to improve surgical access to the posterior orbit. Neural structures, by virtue of their anatomy, at risk with this technique have been functionally assessed in patients postoperatively, comparing operated and nonoperated sides after orbital floor reconstruction using this technique.

& Volume 25, Number 2, March 2014

Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.

557


Ricketts et al


FIGURE 1. The left orbit. The bony orbital floor consists of the orbital process of the zygoma (Z) and maxilla (M) and orbital process of the palatine bone (P). The posterior extent of the orbital process of the maxilla lies medial to the infraorbital sulcus in the floor where it is relatively thin and often fractured. The orbital process of the palatine bone (P), however, is thicker and frequently remains intact in a floor fracture as the ‘‘posterior ledge.’’ The contents of the IOF lie immediately lateral to this posterior ledge. Infraorbital sulcus (IOS), superior orbital fissure (SOF), greater wing of the sphenoid (S), optic canal (OC), ethmoid (E), and lacrimal (L) bones.

Surgical Anatomy A detailed knowledge of orbital anatomy is required to safely perform selective transection of IOF contents, which spares the infraorbital nerve.

Bony Anatomy The IOF is bounded anteromedially by the orbital processes of both the maxilla, which is relatively thin and therefore often fractured, and palatine bone, which is thicker and generally remains intact. Posterolaterally, it is bounded by the greater wing of the sphenoid and the orbital surface of the zygoma (Fig. 1).

FIGURE 2. A, Intraoperative photograph of left orbit showing IOF contents, infraorbital nerve (IO), medial bony shelf (MS), and the bony floor defect (D). B, Closer view of the same orbit: IOF contents being retracted cephalad, emanating from fissure anterior to posterior aspect of lateral orbital wall, infraorbital nerve (IO), defect in orbital floor (D), medial bony shelf (MS). Broken line indicates location of IOF content transection. C, The same view after transection of IOF contents (long arrow) lateral to infraorbital nerve (IO): lateral orbital wall posterior to IOF (PLS) is now visible and accessible for stabilizing plate. Orbital plate of palatine bone (short arrow) medial to IOF is now visible and accessible for orbital plate stabilization. D indicates bony defect; MS, medial bony shelf.

IOF Contents The contents of the fissure include (1) maxillary (V2) division of the trigeminal nerve, (2) zygomatic nerve, (3) infraorbital artery, and (4) sympathetic rami from the pterygopalatine ganglion.10 The maxillary nerve emerges from the posterior/midportion of the IOF to become the infraorbital nerve. This nerve courses anteromedially in the infraorbital groove, becoming encased by a bony roof anteriorly to become the infraorbital canal. Finally, it emerges through the infraorbital foramen, located about 1 cm inferior to the infraorbital margin on a vertical line drawn downward from the supraorbital incisura11 to supply sensation to the lower eyelid, anterior cheek, and upper lip and teeth. The zygomatic nerve, itself a branch of the maxillary nerve, carries parasympathetic secretory fibers to the lacrimal gland, therefore effecting tear production. Terminally, it bifurcates into the zygomaticotemporal and zygomaticofacial nerves that provide sensory innervation to temple and malar regions, respectively. The zygomaticotemporal nerve exits the orbit approximately 20 degrees superolateral to, and 1 cm from, the anterior aspect of the IOF.12 As such, dissection of the lateral orbital wall necessitates transection or avulsion of this nerve at this point. After traversing the bone, it emerges through the zygomaticotemporal foramen and pierces the temporal fascia about 2 cm above the zygomatic arch (Figs. 3A, B). The zygomaticofacial nerve exits the orbit collinearly with the IOF, approximately 8 mm anterolaterally.10 The nerve then exits the zygomatic body through the zygomaticofacial foramen, a mean

558

distance of 26.2 mm inferior to the zygomaticofrontal suture.13 Based on the anatomic course of this nerve, routine dissection of the orbital floor anterior to the IOF necessitates its transection or avulsion (Fig. 4). The divergence of the infraorbital nerve from the zygomatic nerve in the posterior/midportion of the IOF allows selective

FIGURE 3. A, Zygomaticotemporal nerve (arrow) as it exits the lateral orbit (orbital side). L indicates lateral orbital rim; SO, supraorbital rim. B, Zygomaticotemporal nerve (long arrow) as it exits the lateral orbital wall (temporal side) cephalad to the zygomatic arch (short arrow). TF indicates temporal fossa; Z, zygoma; T, temporalis.

* 2014 Mutaz B. Habal, MD




Inferior Fissure Contents Transection

FIGURE 4. Zygomaticofacial nerve exiting orbit (short arrow) and emanating from its foramen (long arrow) in the zygoma (Z). L indicates lateral orbital rim; Z, body of zygoma; T, temporalis.

FIGURE 5. Postoperative sagittal CT image of patient pictured in Figures 1AYC, showing Porex-coated titanium mesh orbital floor reconstruction. Note: Reconstruction plate rests on orbital plate of palatine bone (seen in Figure 2C), just anteromedial to IOF.

transection of inferior fissure contents anteriorly (chiefly, the zygomatic nerve and surrounding soft tissues), while preserving the infraorbital nerve, which provides critical facial sensibility. This allows for increased exposure and visualization of the orbital floor during orbital surgery as described below.

high-energy orbital trauma.4 If the inferior fissure contents lie between the floor defect and this posterolateral stable bone, part of the greater wing of sphenoid, the latter cannot be properly visualized or accessed, and the reconstructive plate or graft will sit on the potentially mobile soft tissues of the IOF contents rather than on stable bone. Consequently, removing the retractor that holds these soft tissues cephalad may result in an inadvertent displacement of the reconstructive plate or graft as the soft tissues revert back to their original position. Selectively transecting the contents of the IOF allows for direct access to the posterolateral orbital ledge (greater wing of sphenoid) defining the lateral defect extent in instances when the defect includes the fissure itself. In the senior author’s experience, the added stability gained by this direct implant to bone contact precludes the need for screw fixation of the orbital plate (Fig. 5).

Surgical Technique The orbital floor is accessed using any of the standard incisions preferred by the surgeon. The senior author (J.A.F.) prefers the retroseptal transconjunctival incision. Subperiosteal dissection along the intact lateral orbital wall or lateral floor facilitates access to the anterolateral apex of the IOF. The infraorbital nerve is identified in the floor defect anteriorly and carefully dissected free of the orbital contents cephalad to it with a fine periosteal elevator. This is, in effect, a continuation of the lateral subperiosteal dissection. The nerve is dissected from above, leaving it caudal in the defect, to its emergence from the IOF (Fig. 2A). In this way, the entire fissure lateral to and above the infraorbital nerve is exposed. The IOF contents are now retracted cephalad, leaving the infraorbital nerve caudally out of harm’s way. The orbital soft tissues (primarily fat) are gently teased up away from the IOF contents using the greater wing of sphenoid that is behind the upwardly retracted fissure contents as a firm backing for this maneuver. A needle-tipped monopolar electrodiathermy is now used to transect the IOF contents just above the opening of the fissure against the bony upper lip that defines the posterolateral limit of the fissure (greater wing of sphenoid). This transection extends from just above the apex of the fissure at its lateral extent to just above and medial to the infraorbital nerve medially (Fig. 2B). The periorbita posterior to the fissure is now carefully dissected in a cephalic direction to reveal the posterior aspect of the lateral orbital wall. This will provide a bony surface for reconstructive plate placement where otherwise the plate would rest on the soft, mobile IOF contents. Upward (cephalic) retraction will now reveal the orbital plate of the palatine bone on the medial side of the fissure that can be dissected minimally in the subperiosteal plane to develop a posterior ledge (Fig. 2C). The confluence of this ledge with the medial ledge (orbital plate of the ethmoidal bone) can now be safely exposed in the subperiosteal plane defining the circumferential bony defect. In addition, the lateral bony ledge (or the lateral limit of the floor defect), also essential as a support to rest an implant for replacement of the orbital floor, may lie posterolateral to the IOF if the floor defect extends to and includes the fissure itself. In effect, the lateral ledge, in such instances, is the posterior bony border of the inferior fissure itself. This is not an uncommon configuration in

MATERIALS AND METHODS To assess facial sensation and lacrimal function that relate to transection of neural structures with IOF contents, 8 patients who had isolated unilateral orbital floor fractures and who had undergone

FIGURE 6. Schematic diagram showing the 3 sensory regions tested using static and dynamic 2-point discrimination and Semmes-Weinstein monofilament. ZT indicates zygomaticotemporal nerve; ZF, zygomaticofacial nerve; IO, infraorbital nerve.



559


Ricketts et al


TABLE 1. Normal Values for Facial Sensation in Zygomaticotemporal, Zygomaticofacial, and Infraorbital Nerve Territories ZT Author

n

Stat2P, mm

ZF

ION

Mov2P, mm Mono, mm Stat2P, mm Mov2P, mm Mono, mm

14

Costas et al 105 15.0 T 5.0 (mean T SD) 42 10.6 Dellon et al15 36 13.4 T 2.8 (meanT 2SD) Posnick et al16 60 Kesarwani et al17 28 Chen et al18 Vriens and van der Glas19 100

8.2 11.8 T 2.6

0.88 1.95 T 0.39

6.5

4.7

0.71

Stat2P, mm

Mov2P

Mono, mm

11.6 T 3.8 5.1 3.8 0.76 9.0 T 2.2 7.9 T 2.4 1.84 T 0.30 11.5 T 4.6 (meanTSD) 9 T 3.3 10.1 (UL) 13.1 T 1.9 (meanTSD)

ZT indicates zygomaticotemporal region; ZF, zygomaticofacial region; ION, infraorbital nerve region; Stat2P, static 2-point; Mov2P, moving 2-point; Mono, Semmes-Weinstein monofilament.

reconstruction with implant placement were enrolled. Surgeries were between January 2012 and June 2013 and by a single operator, the principal investigator (J.A.F.). Patients were reviewed at mean time of 6.8 months (range, 5Y13 months) for an eye examination and lacrimal assessment with a Schirmer test as well as sensory testing. These assessments were carried out by an independent blinded expert (H.F.C.). Sensory assessment consisted of static 2-point, moving 2-point, and monofilament (Semmes-Weinstein) testing for cutaneous facial territories supplied by each of zygomaticofacial, zygomaticotemporal, and infraorbital nerves (Fig. 6.). Both operated and nonoperated sides were assessed and compared for differences using 2-sided paired t tests. Tests of noninferiority were also carried out with the nonoperated side serving as the control. These analyses involved comparing the operated mean to the control mean and using a T 1 SD region around the control mean as the noninferiority region. The SDs used were taken from previously published normal values for facial sensation (Table 1)14Y19 and lacrimal function.20 This article conforms to the Declaration of Helsinki, and institutional research ethics board approval was obtained for the study.

RESULTS Mean values for 2-point (static and moving) discrimination as well as monofilament (Semmes-Weinstein) sensitivity for the 3 areas tested on the face are shown in Table 2. Results are tabulated for nonoperated (control) and operated sides. Operated and nonoperated sides were compared using a Student t test (Table 3). Noninferiority testing was also used to compare operated and nonoperated sides (Table 4). Values for Basic Tear Secretion Test are seen in Table 5, as well as comparative analysis for this test (Table 6). All operated side values fell inside published reference ranges for facial sensation and lacrimal function. Comparative analysis of sides using the t test showed no difference in the 3 regions or 3 sensory modalities, except for 2-point discrimination in the zygomaticotemporal region. Tests of noninferiority showed equivalence across all regions and modalities

except static 2-point discrimination in the zygomaticofacial and infraorbital regions.

DISCUSSION Difficulties achieving anatomic restoration of the orbital floor are more common in large, posterior orbital floor defects and may be due in part to inadequate visualization of and access to the posterior ledge upon which the implant must be placed.5 The justification for selective IOF content transection to improve stable, effective placement of an orbital implant is based on several technical considerations: First, the infraorbital nerve and main maxillary (V2) trunk are preserved in this technique. The infraorbital nerve, as a structure that travels caudal to the orbital contents just deep to the orbital periosteum, can be dissected away from the contents in the subperiosteal plane with relative ease.4 As noted in the anatomic description above, it diverges from the zygomatic nerve and runs in the infraorbital groove. It is therefore left caudal to the upwardly retracted inferior fissure contents and can be preserved without obstructing access or visualization of the posterolateral or posterior orbit. Likewise, the main maxillary (V2) trunk is preserved and is left intact, caudally, in the posterior-most aspect of the fissure. Second, the zygomaticofacial nerve, if not already disrupted by a fracture through the floor of the orbit, as a matter of course, will be avulsed or transected by routine subperiosteal orbital floor dissection, whether the IOF contents are transected or not. Third, the zygomaticotemporal nerve, although likely not disrupted in an isolated orbital floor dissection because of its more cephalic location on the lateral orbital wall, is likely universally transected or avulsed in the subperiosteal exposure of the lateral orbital wall in, for instance, zygomatic fracture repair or zygomatic osteotomy. These nerve disruptions, a likely consequence of routine dissections of the posterolateral orbit, may explain the findings by Fogac¸a et al21 that 100% of patients who underwent orbital floor reconstruction in the setting of zygoma fractures had abnormal quantitative sensibility in the zygomaticotemporal region.

TABLE 2. Mean (SD) Values for Facial Sensation for Nonoperated and Operated Sides ZT

Nonoperated (n = 8) Operated (n = 8)

ZF

ION

Stat2P (SD)

Mov2P (SD)

Mono (SD)

Stat2P (SD)

Mov2P (SD)

Mono (SD)

Stat2P (SD)

Mov2P (SD)

Mono (SD)

13.13 (2.40) 13.31 (2.10)

11.5 (2.39) 13.75 (1.25)

1.98 (0.47) 2.40 (0.92)

12.63 (1.41) 12.38 (2.13)

11.88 (2.99) 12.63 (2.91)

2.13 (0.75) 2.25 (0.79)

11.00 (0.82) 11.86 (3.22)

9.86 (3.08) 12.5 (2.89)

2.27 (0.93) 2.56 (1.08)

Values are in millimeter. ZT indicates zygomaticotemporal region; ZF, zygomaticofacial region; ION, infraorbital nerve region; Stat2P, static 2-point; Mov2P, moving 2-point; Mono, Semmes-Weinstein monofilament.

560





TABLE 3. Table of Mean Differences (Operated vs Nonoperated Sides) for Each of the Sensory Regions

Inferior Fissure Contents Transection

TABLE 5. Mean Values for Basic Tear Secretion Test (in mm) Basic Tear Secretion Test Mean (SD)

Sensory Region Zygomaticotemporal

Zygomaticofacial

Infraorbital

Modality

Mean Difference, mm

P

Static Moving 2-point Monofilament Static Moving 2-point Monofilament Static Moving 2-point Monofilament

0.19 2.25 0.42 j0.25 0.75 0.12 0.86 2.64 0.29

0.89 0.02 0.28 0.77 0.65 0.78 0.53 0.18 0.59

In our study, patients were assessed postoperatively for facial sensation and lacrimal function after having IOF transection at the time of orbital floor reconstruction. Zygomaticotemporal, zygomaticofacial, and infraorbital sensation was assessed with 3 modalities (static 2-point, moving 2-point, and Semmes-Weinstein monofilament) and compared with the nonoperative side. Comparative analysis, with a t test, of sensory values for operated and nonoperated sides showed no difference for each of the 3 modalities in the 3 sensory regions except for dynamic 2-point discrimination in the zygomaticotemporal region (Table 3). Noninferiority testing was used with the aim of showing that the technique lies within the reference range of variability expected around controls as defined by a 1 SD region taken from published values. Of the 9 tests (3 modalities in 3 sensory regions), 7 showed noninferiority, and 2 showed nonequivalence (Table 4). Noninferiority suggests that these sensory values on the operated side are within what has been defined as a reference range, and therefore the technique is considered noninferior with relation to sensory and lacrimal function. The sensory tests showing nonequivalence (static 2-point discrimination for zygomaticofacial and infraorbital regions) could be explained with consideration of the following. First, the mean difference between sides in values for infraorbital nerve sensation suggests poorer sensation on the operated side. This is not unexpected because decreased sensation in this region is commonplace after orbital floor fracture and attributable to the proximity of the nerve to the fracture site.21 Second, mean differences in sensory values for the zygomaticofacial nerve suggest better sensation on the operated side when it is deliberately cut as part of the technique. This intuitively seems nonsensical and is likely an outlier. In addition, the small sample size makes the data set prone to outliers such as these, and third, comparison with normative data from previous publications (Table 1). places all values for the 3 sensory regions for the operated side within a reference range of facial sensation. The latter suggests that any detected decreased sensation on the

TABLE 4. Tests of Noninferiority Sensory Region Zygomaticotemporal

Zygomaticofacial

Infraorbital

Modality

Mean Difference

Static Moving 2-point Monofilament Static Moving 2-point Monofilament Static Moving 2-point Monofilament

0.19 2.25 0.43 j0.25 0.75 0.12 0.86 2.64 0.29 j1.00

Basic Tear Secretion Test

SD

Assessment

3.42 Noninferior 2.10 Noninferior 1.04 Noninferior 2.31 Not equivalent 4.44 Noninferior 1.14 Noninferior 3.45 Not equivalent 4.63 Noninferior 1.37 Noninferior 5.55 Noninferior

Nonoperated Operated

15.00 (10.73) 14.00 (11.05)

operated side (infraorbital nerve region) falls within an expected range of normal sensation and may be due to normal variation. Lacrimal function was assessed with a Basic Tear Secretion Test 1 with anesthetic (basic secretion test) for both operative and nonoperative sides. Mean values for operative sides were 14 mm, and nonoperative sides 15 mm (Table 5). See Table 6 for reference range.20 Comparative analysis showed no difference in operated versus nonoperated sides for this test (Table 7). and noninferiority testing showed equivalence, suggesting that lacrimal function on the operated side was within expected reference range. Based on the above, we conclude that selective IOF content transection does not result in a significant loss of function for those neural structures associated with, and at risk by, the technique. Furthermore, measured sensation in these regions appears to remain within or return to reported reference range following the use of this technique. Therefore, it can be assumed that utilization of selective IOF content transection, for the purpose of better posterior orbit visualization for orbital floor reconstruction, would result in no greater morbidity than that attributable to currently accepted surgical techniques that entail de facto disruption of these nerves. In addition, the morbidity of transecting vascular and autonomic structures of the fissure contents must be considered. Results of comparing the operated to nonoperated side suggest retention or restoration of normal ranged function from presumed disruption of parasympathetic fibers supplying the lacrimal apparatus. The efficacy of selective IOF transection in facilitating better posterior and posterolateral orbital shelf visualization can be assessed only in a randomized trial comparing orbital floor reconstruction outcomes (ie, postoperative global dystopia, entrapment, etc). with and without selective IOF transection, performed by the same surgeon in otherwise anatomically identical cases. Such a study is not feasible, given the multiple factors that determine these outcomes. In this article, we have described the technique of selective IOF transection and demonstrate its value by illustrating photographically the improved visualization of the posterior ledge facilitated by it. In addition, we have quantitatively demonstrated that minimal morbidity results from utilization of the technique.

CONCLUSIONS Although not required for all orbital floor repairs, the described technique of selective transection of some of the neurovascular structures of the IOF improves visualization and access to the posterior orbit. It allows stable anatomic placement of reconstructive material on bony ledges in those instances in which the posterior ledge is small (usually composed only of the orbital plate of the palatine bone) and/or the bony defect extends to or beyond the IOF. We found no evidence of increased morbidity with the transection of IOF contents as compared

TABLE 6. Expected Values for Basic Tear Secretion Test20 G5

Highly Suggestive of Aqueous Tear Deficiency

5Y10 Q10



Equivocal Normal

561


Ricketts et al

TABLE 7. Comparative Analysis for Basic Tear Secretion Test Operated Versus Nonoperated Sides

Basic Tear Secretion Test

Mean Difference, mm

P

j1.00

0.63

with normal sensory and lacrimal function, and indeed, it may reduce implant-related morbidity associated with malposition.

REFERENCES 1. Brucoli M, Arcuri F, Cavenaghi R, et al. Analysis of Complications After Surgical Repair of Orbital Fractures. J Craniofac Surg 2011;22 2. Mauriello JA Jr. Case report inferior rectus muscle entrapped by Teflon implant after orbital floor fracture repair. Ophthal Plast Reconstr Surg 1990 3. Heitsch M, Mohr C. Blindness as a complication following surgical orbital floor revision. Consequences for the surgical procedures. Fortschr Kiefer Gesichtschir 1991;36:152Y153 4. Evans BT, Webb AAC. Post-traumatic orbital reconstruction: anatomical landmarks and the concept of the deep orbit. Br J Oral Maxillofac Surg 2007;45:183Y189 5. Fisher DM, Cheung C, Pirouzmand F. The posterior ledge in the management of orbital floor fractures. In: Chen Y, ed. Craniofacial Surgery 8. Monduzzi Editore, 1999:363Y365 6. Saunders CJ, Whetzel TP, Stokes RB, et al. Transantral endoscopic orbital floor exploration: a cadaver and clinical study. Plast Reconstr Surg 1997;100:575Y581 7. Palmieri CF, Ghali GE. Late correction of orbital deformities. Oral Maxillofac Surg Clin North Am 2012;24:649Y663 8. Pearl RM. Prevention of enophthalmos: a hypothesis. Ann Plast Surg 1990;25:132Y133

562


9. Glassman RD, Manson PN, Petty P, et al. Techniques for improved visibility and lid protection in orbital explorations. J Craniofac Surg 1990;1:69Y71 10. Aziz KMA, Froelich SC, Cohen PL, et al. The one-piece orbitozygomatic approach: the MacCarty burr hole and the inferior orbital fissure as keys to technique and application. Acta Neurochir (Wien) 2002;144:15Y24 11. Canan S, Asim OM, Okan B, et al. Anatomic variations of the infraorbital foramen. Ann Plast Surg 1999;43:613Y617 12. Hwang K, Suh MS, Lee SI, et al. Zygomaticotemporal nerve passage in the orbit and temporal area. J Craniofac Surg 2004;15:209Y214 13. Aksu F, Ceri NG, Arman C, et al. Location and incidence of the zygomaticofacial foramen: an anatomic study. Clin Anat 2009;22:559Y562 14. Costas PD, Heatley G, Seckel BR. Normal sensation of the human face and neck. Plast Reconstr Surg 1994;93:1141Y1145 15. Dellon AL, Andonian E, DeJesus RA. Measuring sensibility of the trigeminal nerve. Plast Reconstr Surg 2007;120:1546Y1550 16. Posnick JC, Zimbler AG, Grossman JA. Normal cutaneous sensibility of the face. Plast Reconstr Surg 1990;86:429Y433, discussion 434Y435 17. Kesarwani A, Antonyshyn O, Mackinnon SE, et al. Facial sensibility testing in the normal and posttraumatic population. Ann Plast Surg 1989;22:416Y425 18. Chen CC, Essick GK, Kelly DG, et al. Gender-, side- and site-dependent variations in human perioral spatial resolution. Arch Oral Biol 1995;40:539Y548 19. Vriens JPM, van der Glas HW. Extension of normal values on sensory function for facial areas using clinical tests on touch and two-point discrimination. Int J Oral Maxillofac Surg 2009;38:1154Y1158 20. Liesegang TJ, Skuta GL, Cantor LB. American Academy of Ophthalmology, Basic and Clinical Science Course. Basic and Clinical Science Course Section 8VExternal Disease and Cornea. San Francisco, CA, 2006 21. Fogac¸a WC, Fereirra MC, Dellon AL. Infraorbital nerve injury associated with zygoma fractures: documentation with neurosensory testing. Plast Reconstr Surg 2004;113:834Y838



[Topography of the orbital contents. I: Eye muscles, orbital walls and internal contents].

Deep Orbital Dermoid Cyst Bulging into the Superior Orbital Fissure: Clinical Presentation and Management.

Fixation of fractured inferior orbital wall using fibrin glue in inferior blowout fracture surgery.

An Alternative Route for Entrapped Inferior Orbital Nerve in Orbital Floor Fracture.

Superior orbital fissure syndrome and bilateral internal carotid pseudoaneurysms.

Orbital decompression surgery and horse chestnut seed extract improved superior orbital vein blood flow in patients with thyroid-associated ophthalmopathy.

Orbital Floor Restoration Using the Transnasal Balloon Technique for Inferior Orbital Wall Fracture.

Analysis of symptoms according to areas of orbital floor in orbital inferior wall fractures.

[Topography of orbital contents. II: Compartments of the orbital adipose body].

Superior orbital fissure syndrome. Review of 130 cases.

Complications of surgery for orbital tumors.

Microdebrider use in orbital surgery.

Medial and Superior Orbital Decompression: Improving Access for Endonasal Endoscopic Frontal Sinus Surgery.

Ophthalmic plastic and orbital surgery in Taiwan.

Navigational area of the cranio-orbital foramen and its significance in orbital surgery.

Piezosurgery for orbital decompression surgery in thyroid associated orbitopathy.

General anaesthetic considerations for haemostasis in orbital surgery.

Delayed-onset inferior rectus muscle hematoma after orbital floor fracture.

Isolated inferior rectus muscle rupture after blunt orbital trauma.

hydroxylapatite implant for orbital reconstructive surgery.

[Current aspects of eyelid, lacrimal and orbital surgery in childhood].

A Statistical Analysis of Superior Orbital Fissure Width in Korean Adults using Computed Tomography Scans.

Optic neuropathy after orbital decompression surgery.

Bilateral Orbital Abscesses After Strabismus Surgery.