Surgical Approaches to the Facial Skeleton 3rd Edition PDF

Surgical Approaches to the Facial Skeleton THIRD EDITION 2 Surgical Approaches to the Facial Skeleton THIRD EDITION EDITORS EDWARD ELLIS III, DDS, MS Professor, Oral and Maxillofacial Surgery Director of Residency Training The University of Texas Sou...

Surgical Approaches to the Facial Skeleton THIRD EDITION 2 Surgical Approaches to the Facial Skeleton THIRD EDITION EDITORS EDWARD ELLIS III, DDS, MS Professor, Oral and Maxillofacial Surgery Director of Residency Training The University of Texas Southwestern Medical Center and Chief of Oral and Maxillofacial Surgery Parkland Memorial Hospital Dallas, Texas MICHAEL F. ZIDE, DMD Associate Director, Oral and Maxillofacial Surgery John Peter Smith Hospital Fort Worth, Texas VIDEO EDITORS ERIC W. WANG, MD Associate Professor Department of Otolaryngology University of Pittsburgh School of Medicine Director 3 Maxillofacial Trauma UPMC Presbyterian Hospital Pittsburgh, Pennsylvania JENNY Y. YU, MD Vice Chair, Clinical Operations Department of Ophthalmology Assistant Professor Department of Ophthalmology and Otolaryngology University of Pittsburgh Medical Center Pittsburgh, Pennsylvania Illustrations by Jennifer Carmichael, MA and Lewis Calver, BFA, MS 4 Acquisitions Editor: Keith Donnellan Marketing Manager: Stacy Malyil Production Project Manager: Kim Cox Design Coordinator: Stephen Druding Editorial Coordinator: Dave Murphy Manufacturing Coordinator: Beth Welsh Prepress Vendor: SPi Global Third edition Copyright © 2019 Wolters Kluwer Copyright © 2006 by Lippincott Williams & Wilkins. Copyright © 1995 J. B. Lippincott Company. All rights reserved. This book is protected by copyright. No part of this book may be reproduced or transmitted in any form or by any means, including as photocopies or scanned-in or other electronic copies, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews. Materials appearing in this book prepared by individuals as part of their official duties as U.S. government employees are not covered by the above- mentioned copyright. To request permission, please contact Wolters Kluwer at Two Commerce Square, 2001 Market Street, Philadelphia, PA 19103, via email at [email protected], or via our website at lww.com (products and services). 9 8 7 6 5 4 3 2 1 Printed in China (or the United States of America) Library of Congress Cataloging-in-Publication Data Names: Ellis, Edward, DDS, author. | Zide, Michael F., author. Title: Surgical approaches to the facial skeleton / Edward Ellis, III, Michael F. Zide ; surgical videos by Eric W. Wang, Jenny Y. Yu. Description: Third edition. | Philadelphia : Wolters Kluwer, | Includes bibliographical references and index. Identifiers: LCCN 2017058293 | ISBN 9781496380418 (hardback) Subjects: | MESH: Facial Bones—surgery Classification: LCC RD523 | NLM WE 705 | DDC 617.5/2059—dc23 LC record available at https://lccn.loc.gov/2017058293 This work is provided “as is,” and the publisher disclaims any and all warranties, express or implied, including any warranties as to accuracy, comprehensiveness, or currency of the content of this work. This work is no substitute for individual patient assessment based upon healthcare professionals’ examination of each patient and consideration of, among other 5 things, age, weight, gender, current or prior medical conditions, medication history, laboratory data and other factors unique to the patient. The publisher does not provide medical advice or guidance and this work is merely a reference tool. Healthcare professionals, and not the publisher, are solely responsible for the use of this work including all medical judgments and for any resulting diagnosis and treatments. Given continuous, rapid advances in medical science and health information, independent professional verification of medical diagnoses, indications, appropriate pharmaceutical selections and dosages, and treatment options should be made and healthcare professionals should consult a variety of sources. When prescribing medication, healthcare professionals are advised to consult the product information sheet (the manufacturer's package insert) accompanying each drug to verify, among other things, conditions of use, warnings and side effects and identify any changes in dosage schedule or contraindications, particularly if the medication to be administered is new, infrequently used or has a narrow therapeutic range. To the maximum extent permitted under applicable law, no responsibility is assumed by the publisher for any injury and/or damage to persons or property, as a matter of products liability, negligence law or otherwise, or from any reference to or use by any person of this work. LWW.com 6 Dedication Plant a seed and it will grow. There are many who have unknowingly contributed to this book through the education they have provided me. All were my teachers, all are my friends. This book is dedicated to these special individuals: Robert Bruce Amir El-Attar W. James Gallo James Hayward Kazumas Kaya Khursheed Moos Timothy Pickens Gilbert Small George Upton Al Weiss EDWARD ELLIS III In gratitude for ageless friendship and counsel. Doug Sinn, DDS, Jack Kent, DDS, and Robert V. Walker, DDS. To Riki: who puts up with me still. MICHAEL F. ZIDE 7 PREFACE There are many reasons for exposing the facial skeleton. Treatment of facial fractures, management of paranasal sinus disease, esthetic onlay and recontouring procedures, elective osteotomies, treatment of secondary traumatic deformities such as enophthalmos, placement of endosteal implants, and a host of other reconstructive procedures require approaches to the facial framework. Many approaches to a given skeletal region are possible. The choice is made usually on the basis of the surgeon's training, experience, and bias. This book does not advocate one approach over another, although the advantages and disadvantages of each approach will be listed. We maintain the age-old belief that “many roads lead to Rome.” Therefore, the purpose of this book is to describe in detail the anatomical and technical aspects of most of the commonly used surgical approaches to the facial skeleton. We have deliberately not presented every approach, because many of them are not universally used, or are so simple that nothing needs to be said. However, the approaches presented in this book will allow the surgeon complete access to the craniofacial skeleton for whatever skeletal procedure is being performed. We have attempted, from the beginning, to make Surgical Approaches to the Facial Skeleton different from the other books that touch on this subject. Most books that discuss surgical approaches do so in the context of the surgical procedure that is being presented. For instance, a book on facial fractures will usually present surgical approaches to a particular facial fracture. However, the surgical approach is not generally given much consideration or is it presented in sufficient detail for the novice. The reader is often left with the question, “How did the author get from the skin to that point on the skeleton?” We instead avoid consideration of why one is exposing the skeleton and describe the approaches in great detail so that even the novice can safely approach the facial skeleton by following the step-by-step description we have provided. This book assumes that the reader has some basic understanding of regional anatomy, especially osteology. However, the anatomic structures 8 of greatest interest will still be discussed for each surgical approach. This book also assumes that the reader has developed skills for the careful handling of soft tissues. We have suggested the use of those instruments that we have found useful for incising, retracting, and manipulating the tissues involved with each surgical approach, recognizing that others are also appropriate. The book also assumes that the reader is skilled in facial soft tissue closure. We have not discussed skin closure techniques associated with the approaches unless they differ from routine skin closures. The first edition of Surgical Approaches to the Facial Skeleton became a hit with surgeons from several specialties when it was published in 1995. Oral and maxillofacial surgeons, plastic surgeons, and otolaryngologists all wanted this book for their collections. The book was most popular, however, among residents-in-training from these specialties. The third edition of Surgical Approaches to the Facial Skeleton, like the first two editions, contains 14 chapters, 13 of which describe a specific surgical approach. The first chapter discusses basic principles involved in surgical approaches. The remaining 13 chapters are organized into sections, predominantly on the basis of the region of the face being exposed. There will often be more than one surgical approach presented for each region, with the choice left to the surgeon. We attempt to point out the advantages and disadvantages of each as they are presented. The major change in the third edition of Surgical Approaches to the Facial Skeleton is the addition of videos. Drs. Eric Wang and Jenny Yu provide narrated videos that demonstrate 12 key approaches as performed on cadavers. Edward Ellis III, DDS, MS Michael F. Zide, DMD 9 Contents Preface Section 1 Basic Principles for Approaches to the Facial Skeleton 1 Basic Principles for Approaches to the Facial Skeleton Section 2 Periorbital Incisions 2 Transcutaneous Approaches Through the Lower Eyelid 3 Transconjunctival Approaches 4 Supraorbital Eyebrow Approach 5 Upper Eyelid Approach Section 3 Coronal Approach 6 Coronal Approach Section 4 Transoral Approaches to the Facial Skeleton 7 Approaches to the Maxilla 8 Mandibular Vestibular Approach Section 5 Transfacial Approaches to the Mandible 9 Submandibular Approach 10 Retromandibular Approach 11 Rhytidectomy Approach 10 Section 6 Approaches to the Temporomandibular Joint 12 Preauricular Approach Section 7 Surgical Approaches to the Nasal Skeleton 13 External (Open) Approach 14 Endonasal Approach Index 11 Surgical Approaches to the Facial Skeleton THIRD EDITION 12  SECTION 1 Basic Principles for Approaches to the Facial Skeleton 13  1 Basic Principles for Approaches to the Facial Skeleton Maximum success in skeletal surgery depends on adequate access to and exposure of the skeleton. Skeletal surgery is simplified and expedited when the involved parts are sufficiently exposed. In orthopaedic surgery, especially of the appendicular skeleton, the basic rule is to select the most direct approach possible to the underlying bone. Therefore, incisions are usually placed very near the area of interest while major nerves and blood vessels are retracted. This involves little regard for esthetics but allows the orthopaedic surgeon greater leeway in the location, direction, and length of the incision. Surgery of the facial skeleton, however, differs from general orthopaedic surgery in several important ways. The first factor in incision placement is not surgical convenience but facial esthetics. The face is plainly visible to everyone, and a conspicuous scar may create a cosmetic deformity that can be as troubling to the individual as the reason for which the surgery was performed. Cosmetic considerations are critical in light of the emphasis that most societies place on facial appearance. Therefore, as we will see in this book, all the incisions made on the face must be placed in inconspicuous areas, sometimes distant from the underlying osseous skeleton on which the surgery is being performed. For instance, placement of incisions in the oral cavity allows superb exposure of most of the facial 14 skeleton, with a completely hidden scar. The second factor that differentiates incision placement on the face from incisions placed anywhere else on the body is the presence of the muscles and nerve (cranial nerve VII) of facial expression. The muscles are subcutaneous structures, and the branches of the facial nerve that supply them can be traumatized if incisions are made in their path. This can result in a “paralyzed” face, which is not only a severe cosmetic deformity but can also have great functional ramifications. For instance, if the ability to close the eye is lost, corneal damage can ensue, affecting vision. Therefore, placement of incisions and dissections that expose the facial skeleton must ensure that damage to the facial nerve is minimized. Many dissections to expose the skeleton require care and electrical nerve stimulation to identify and protect the nerve. Approaches using incisions in the facial skin must also take into consideration the muscles of facial expression. This is especially important for approaches to the orbit, where the orbicularis oculi muscle must be traversed. Closure of some incisions also affects the muscles of facial expression. For instance, if a maxillary vestibular incision is closed without proper reorientation of the perinasal muscles, the nasal base will widen. The third factor in facial incision placement is the presence of many important sensory nerves exiting the skull at multiple locations. The facial soft tissues have more sensory input per unit area than soft tissues anywhere else in the body. Loss of this sensory input can be a great inconvenience to the individual. Therefore, the incisions and approaches used must avoid injury to the sensory nerves. An example is dissection of the supraorbital nerve from its foramen/notch in the coronal approach. Other important factors are the patient’s age, existing unique anatomy, and expectations. The age of the patient is important because of the possible presence of the wrinkles that come with age. Skin wrinkles serve as a guide and offer the surgeon the opportunity to place incisions within or parallel to them. Existing anatomic features that are unique to the individual can also facilitate or hamper incision placement. For instance, pre-existent lacerations can be used or extended to provide surgical exposure of the underlying skeleton. The position, direction, and depth of a laceration are important variables in determining its utility. The presence of old scars may also direct incision placement; the old scar may be excised and used to approach the skeleton. Sometimes, an old scar may not lend itself to use and may even cause the new incision to be positioned such that the old scar is avoided. Hair distribution may also direct the position of incisions. For instance, the incision for the coronal approach is 15 largely determined by the patient’s hairline. Ethnic characteristics also have a bearing on whether an incision will be placed in a conspicuous area. History or ethnic propensity for hypertrophic scarring, keloid formation, and hyper- or hypopigmentation may alter the decision as to whether or where to place an incision. The patient’s expectations and wishes must always be considered in any decision about location of an incision. For instance, patients who repeatedly require treatment of facial injuries may not be concerned with local cutaneous approaches to the naso-orbito-ethmoid region, whereas other individuals may be very concerned about the location of incisions. Therefore, the choice of surgical approach depends at least partly on the patient. Principles of Incision Placement Incisions placed in areas that are not readily visible, such as within the oral cavity or far behind the hairline, are not of esthetic concern. Incisions placed on exposed surfaces of the face, however, must follow some basic principles so that the scar will be less conspicuous. These principles are outlined in the following text. Avoid Important Neurovascular Structures Although this is an obvious consideration, avoiding anatomic hazards during placement of incisions is only a secondary consideration in the face. Instead, placing the incision in a cosmetically acceptable location takes priority. Important neurovascular structures encountered during the dissection must be dealt with by dissecting around them or by retracting them. Use as Long an Incision as Necessary Many surgeons tend to use short incisions. If the soft tissues around a short incision are stretched to obtain sufficient exposure of the skeleton, the additional trauma from retraction may create a less satisfactory scar than a longer incision would. A well-placed long incision may be less perceptible than a short incision that is placed poorly or requires great retraction. A long incision heals as quickly as a short one. Place Incisions Perpendicular to the Surface of Non–hair- 16 bearing Skin Except in some very specific regions, an incision perpendicular to the skin surface permits the wound margins to be reapproximated in an accurate, layer-to-layer manner. Incisions performed obliquely to the surface of the skin are susceptible to marginal necrosis and to overlapping of the edges during closure. Incisions in hair-bearing tissue, however, should be parallel to the direction of the hair so that fewer follicles are transected. An oblique incision requires a more meticulous closure because of the tendency of the margins to overlap during suturing. Subcutaneous sutures may have to be placed more deeply to avoid necrosis of an oblique edge. Place Incisions in the Lines of Minimal Tension The lines of minimal tension, also called relaxed skin tension lines, are the result of the skin’s adaptation to function and are also related to the elastic nature of the underlying dermis (see Fig. 1.1). The intermittent and chronic contractions of the muscles of facial expression create depressed creases in the skin of the face. These creases become more visible and depressed with age. For instance, the supraorbital wrinkle lines and the transverse lines of the forehead are caused by the contraction of the frontalis muscles, which insert into the skin of the lower forehead. In the upper eyelids, many fine perpendicular strands of fibers of the levator aponeurosis terminate in the dermis of the skin and along the tarsus to form the supratarsal fold. Similar insertions in the lower eyelid create fine horizontal lines, which are accentuated by the circumferential contraction of the orbicularis oculi muscle. 17 FIGURE 1.1 Lines of minimal tension (relaxed skin tension lines) are conspicuous in the aged face. These lines or creases are good 18 choices for incision placement because the scars resulting from the incision will be imperceptible. Incisions should be made within the lines of minimal tension. Incisions made within or parallel to such a line or crease will become inconspicuous if they are closed carefully. Any incision or portion of an incision that crosses such a crease, however, is often conspicuous. Seek Other Favorable Sites for Incision Placement If incisions cannot be placed within the lines of minimal tension, they can be made inconspicuous by placement inside an orifice, such as the mouth, nose, or eyelid; within hair-bearing areas or locations that can be covered by hair; or at the junction of two anatomic landmarks, such as the esthetic units of the face. 19  SECTION 2 Periorbital Incisions 20 A standard series of incisions have been used extensively to approach the inferior, lateral, and medial orbital rims. Properly placed incisions offer excellent access with minimal morbidity and scarring. The most commonly used approaches are those made on the external surface of the lower eyelid, the conjunctival side of the lower eyelid, the skin of the lateral brow, and the skin of the upper eyelid. This section describes these approaches. Other periorbital approaches exist and can be useful. Existing lacerations of 2 cm or longer may also be used or extended to access the orbit. 21  2 Transcutaneous Approaches Through the Lower Eyelid Approaches through the external side of the lower eyelid offer superb exposure to the inferior orbital rim, the floor of the orbit, the lateral orbit, and the inferior portion of the medial orbital rim and wall. These approaches are given many names in the literature (e.g., blepharoplasty, subciliary, lower- or mid-eyelid, subtarsal, infraorbital rim), based primarily on the position of the skin incision in the lower eyelid. Because of the natural skin creases in the lower eyelid and the thinness of eyelid skin, scars become inconspicuous with time and do not form keloids. The infraorbital incision, however, is almost always noticeable to some degree (see Fig. 2.1). 22 FIGURE 2.1 Photograph showing poor cosmetic result from the use of an infraorbital incision. Incisions placed at this level often heal poorly for two reasons: (a) the lateral extension of the incision usually crosses the resting skin tension lines (dots) that cause widening of the scar (arrows) and (b) the incision is in the thicker skin of the cheek rather than the thin skin of the eyelid. Surgical Anatomy Lower Eyelid In the sagittal section, the lower eyelid (1) consists of at least four distinct layers: the skin and subcutaneous tissue, the orbicularis oculi muscle, the tarsus (upper 4 to 5 mm of the eyelid) or orbital septum, and the conjunctiva (see Fig. 2.2). 23 FIGURE 2.2 Sagittal section through the orbit and globe. C, palpebral conjunctiva; IO, inferior oblique muscle; IR, inferior rectus muscle; OO, orbicularis oculi muscle; OS, orbital septum; P, periosteum/periorbita; TP, tarsal plate. 24 Skin The skin is the outermost layer, and comprises the epidermis and the very thin dermis. The skin of the eyelids is the thinnest in the body and has many elastic fibers that allow it to be stretched during dissection and retraction. It is loosely attached to the underlying muscle; therefore, in contrast to most areas of the face, relatively large quantities of fluid may accumulate subcutaneously in this loose connective tissue. The skin derives its blood supply from the underlying perforating blood vessels of the muscles (see subsequent text). Muscle The orbicularis oculi muscle, the sphincter of the eyelids, lies subjacent and adherent to the skin (see Fig. 2.3). This muscle completely encircles the palpebral fissure and extends over the skeleton of the orbit. It can therefore be divided into orbital and palpebral portions (see Fig. 2.4). The palpebral portion can be further subdivided into the pretarsal portion (i.e., the muscle superficial to the tarsal plates) and the preseptal portion (i.e., the muscle superficial to the orbital septum). The palpebral portion of the orbicularis oculi muscle is very thin in cross section, especially at the junction of the pretarsal and preseptal portions. The orbital portion of the orbicularis oculi muscle originates medially from the bones of the medial orbital rim and the medial canthal tendon. The peripheral fibers sweep across the eyelid over the orbital margin in a series of concentric loops, the more central ones forming almost complete rings. In the lower eyelid, the orbital portion extends below the inferior orbital rim onto the cheek and covers the origins of the elevator muscles of the upper lip and nasal ala. The orbital portion of the orbicularis oculi muscle is responsible for tight closure of the eye. The preseptal portion of the orbicularis oculi muscle originates from the medial canthal tendon and lacrimal diaphragm and passes across the eyelid as a series of half-ellipses, meeting at the lateral canthal tendon. The upper and lower pretarsal muscles contribute to the lateral canthal tendon which extends approximately 7 mm before inserting lateral orbital tubercle. Medially, they unite to form the medial canthal tendon, which inserts on the medial orbital margin, the anterior lacrimal crest, and the nasal bones. The palpebral portion of the orbicularis oculi muscle functions to close the eye without effort, as in blinking. It also functions to maintain contact between the lower eyelid and the ocular globe. 25 FIGURE 2.3 Anatomic dissection of orbicularis oculi muscle fibers. Note the extreme thinness in this older specimen. 26 FIGURE 2.4 Orbital and palpebral portions of orbicularis oculi muscle. The palpebral portion is divided into the fibers in front of the tarsus (pretarsal portion) and those in front of the orbital septum (preseptal portion). The orbicularis oculi muscle is innervated laterally from the branches of the facial nerve that enter the muscle on its deeper surface. The blood supply to the orbicularis oculi muscle is from the external facial artery tributaries arising from the deep branches of the ophthalmic artery. These arterial branches form a marginal arcade, traversing between the tarsal plate and the muscle and giving rise to branches that perforate the substance of the muscle, the orbital septum, and the tarsal plate. Orbital Septum/Tarsus The orbital septum is a fascial diaphragm between the contents of the orbit and the superficial face (Figs. 2.1 and 2.5). It is usually denser laterally than medially, but varies considerably in thickness from one individual to another, and weakens with age, allowing the orbital fat pads to bulge onto the face. The orbital septum is a fascial extension of the periosteum of the 27 bones of the face and orbit. It originates along the orbital rim for most of its extent. Laterally and inferolaterally, however, it arises from the periosteum 1 to 2 mm beyond the rim of the orbit. Therefore, it is necessary to dissect a few millimeters lateral and/or inferior to the orbital rim before incising the periosteum to prevent incising through the orbital septum. The orbital septum of the lower eyelid inserts into the inferior margin of the lower tarsus. The tarsal plate of the lower eyelid is a somewhat thin, pliable, fibrocartilaginous structure that gives form and support to the lower eyelid (see Fig. 2.6A and B). The edge of the tarsus that is adjacent to the free border of the eyelid is parallel to the palpebral fissure, whereas the deeper (inferior) border is curved such that the tarsus is somewhat semilunar in shape. It is also, of course, curved to conform to the outer surface of the eyeball. The inferior tarsus at approximately 4 to 5 mm is half the height of the superior tarsus (approximately 10 mm). The tarsal glands, sandwiched between the layers of fibrocartilage in the lower eyelid, are smaller than their upper eyelid counterpart, and exit on the eyelid margin near the lash follicles. The lashes are supported by their roots, which are attached to fibrous tissue on the tarsal plate and not in the orbicularis oculi muscle anterior to the tarsal plate. Laterally, the tarsal plate becomes a fibrous band that adjoins the structural counterpart from the upper eyelid, forming the lateral canthal tendon. Medially, the tarsal plate also becomes fibrous and shelters the inferior lacrimal canaliculus behind, as it becomes the medial canthal tendon. 28 FIGURE 2.5 Anatomic dissection of orbital septum in the lower eyelid. Note the thinness in this older specimen. 29 FIGURE 2.6 A: Anterior surface of tarsal plates and canthal tendons (left eye). Note the difference in size between the upper and lower tarsal plates. B: Posterior surface of the tarsal plates and canthal tendons (left eye). Note the vertically arranged Meibomian glands, visible through the thin conjunctiva. Embedded within the tarsal plates are large sebaceous glands called the tarsal or Meibomian glands, whose ducts may be seen along the eyelid margin. A grayish line or a slight groove, which is sometimes visible between the lashes and the openings of the tarsal glands, represents the junction of the two fundamental portions of the eyelid: the skin and muscle on one hand and the tarsus (the plate of closely packed tarsal glands) and conjunctiva on the other. This junction indicates a plane along which the eyelid may be split into anterior and posterior portions with minimal scarring. 30 Palpebral Conjunctiva The conjunctiva that lines the inner surface of the eyelids is called the palpebral conjunctiva (Fig. 2.2). It adheres firmly to the tarsal plate, and as it extends inferiorly toward the inferior conjunctival fornix, it becomes more loosely bound. At the inferior conjunctival fornix, the conjunctiva sweeps onto the ocular globe to become the bulbar conjunctiva. Lateral Canthal Tendon The lateral canthal tendon, ligament, or raphe as it is frequently called, is a fibrous extension of the tarsal plates laterally toward the orbital rim (see Fig. 2.7). As will be seen in the medial canthal tendon, the lateral canthal tendon has a superficial and a deep component. The base of the ligamentous complex is “Y”-shaped and is attached to the external angle of the two tarsi (see Fig. 2.8). The two divisions diverge from the tarsi and the superficial component extends laterally just under, or intermingles with, the orbicularis oculi muscle. It continues laterally to the orbital rim and inserts into the periosteum overlying the lateral orbital rim and the temporalis fascia just lateral to the orbital rim. The superficial limb coalesces with the temporal periosteum over the lateral orbital rim. The thicker, stronger deep component of the lateral canthal tendon courses posterolaterally, inserting into the periosteum of the orbital tubercle of the zygoma, approximately 3 to 4 mm posterior to the orbital rim. The space between the two bundles of the lateral canthal tendon is filled with loose connective tissue. 31 FIGURE 2.7 Anatomic dissection of the deep portion of the lateral canthal tendon. Note that it attaches posterior to the orbital rim. 32 FIGURE 2.8 Medial and lateral canthal tendon complexes. Note that the anterior limb of the medial canthal tendon (AL MCT) and the posterior limb of the lateral canthal tendon (PL LCT) are thicker. The thick anterior portion of the medial canthal tendon attaches to the anterior lacrimal crest of the maxilla and the frontal process of the maxilla. The thinner PL MCT attaches along the posterior lacrimal crest of the lacrimal bone. The thick PL LCT attaches to the orbital (Whitnall) tubercle of the zygoma, 3 to 4 mm posterior to the lateral orbital rim. The thinner anterior fibers course laterally to mingle with the orbicularis oculi muscle fibers and the periosteum of the lateral orbital rim. Medial Canthal Tendon The medial canthal tendon is attached to the medial bony orbit by the superficial and the deep components that attach to the anterior and posterior lacrimal crests (see Figs. 2.8 and 2.9) (2,3). The medial canthal tendon originates at the nasal border of the upper and lower tarsi, where the preseptal muscles divide into superficial and deep heads (4). The 33 lacrimal puncta are located here. Therefore, the lacrimal canaliculi of the upper and lower eyelid margins extend from the medial border of the tarsi toward and behind the medial canthus. Continuing medially, the tendon fans out to insert into the anterior lacrimal crest and beyond onto the frontal process of the maxilla. The anterior lacrimal crest, which is 2 to 3 mm medial to the canthal apex, protects the lacrimal sac. Therefore, an incision farther medial than 3 mm from the canthus misses both the canaliculi and the sac. 34 FIGURE 2.9 Anatomic specimen showing the anterior and posterior components of the medial canthal tendon complex. AL MCT, anterior limb of the medial canthal tendon; ALC, anterior lacrimal crest; LS, lacrimal sac; PL MCT, posterior limb of the medial canthal tendon; PLC, posterior lacrimal crest. The anterior horizontal segment is the strongest component of the medial canthal tendon complex and is attached most firmly at the anterior lacrimal crest. The thinner posterior limb inserts into the posterior lacrimal crest and functions to maintain the eyelids in a posture tangential to the globe. The resultant vector of all the canthal attachments suggests that resuspension of the entire complex following disruption should be posterior and superior to the anterior lacrimal crest. Infraorbital Groove The infraorbital neurovascular bundle enters the posterior orbit through the inferior orbital fissure and runs almost straight anteriorly in the infraorbital 35 groove of the orbital floor (see Fig. 2.10). More anteriorly, the infraorbital groove is usually covered with a thin layer of bone, forming the infraorbital canal, which leads the neurovascular bundle through the infraorbital foramen to the superficial structures of the face. The superior alveolar nerves split off the infraorbital nerve at a depth of 5 to 25 mm within the infraorbital canal and give sensation to the maxillary teeth and gingiva. Techniques Several external incisions of the lower eyelid to allow access to the infraorbital rim and orbital floor have been described. The major difference between these incisions is the level at which they are placed on the skin of the eyelid and the level at which the muscle is transected to expose the orbital septum/periosteum. Each incision has advantages and disadvantages. 36 FIGURE 2.10 Anatomic dissection of the orbital floor, lateral and inferior orbital rims. IOF, inferior orbital fissure after incision of contents; ION, infraorbital nerve in canal/groove after unroofing; ZFN, zygomaticofacial nerve; ZTN, zygomaticotemporal nerve. The two approaches and one modification are illustrated in the following text. The first is most commonly called the subciliary incision, also known as the infraciliary or blepharoplasty incision. This incision is made just below the eyelashes. The advantages of this incision are the imperceptible scar and the ease of extending laterally for additional exposure of the entire lateral orbital rim. The second approach is usually known as the subtarsal, also known as the mid-eyelid or skin crease approach, because the incision is made lower than that in the subciliary approach, often 4 to 7 mm below the eyelid margin. The subciliary approach will be shown in great detail. The subtarsal approach will be contrasted to the subciliary approach. In addition to these approaches, a modification of the subciliary approach, which can provide access to the entire lateral rim and internal wall of the orbit, will also be illustrated. 37 Technique for Subciliary Approach The skin incision is made just below the eyelashes. Three surgical paths are available to access the orbital rim—the “skin flap” dissection, the “skin–muscle” flap dissection, and the “step” dissection. Briefly, the “skin flap” approach involves dissecting the thin eyelid skin from the subciliary incision down to the level of the orbital rim. Subsequently, the orbicularis oculi and the periosteum are transected just below the orbital rim. The “skin–muscle” flap proceeds through both the skin and the pretarsal muscle, directly atop the inferior tarsal plate, and dissects down the orbital septum, toward the orbital rim, where an incision is made through the periosteum to the bone. The “step” dissection is technically easier and abrogates the common complications associated with the other two methods, namely, skin or septal buttonholes, darkening of the skin, ectropion, and occasionally entropion. The “step” dissection preserves pretarsal fibers of the orbicularis oculi, thereby limiting scarring at the eyelid margin and maintaining the position of the eyelid and its contact with the globe (Video 2.1). STEP 1. Protection of the Globe Protecting the cornea during surgical procedures around the orbit may reduce ocular injuries. If surgery is performed on the skin side of the eyelids to approach the orbital rim and/or orbital floor, a temporary tarsorrhaphy or scleral shell may be useful. These are simply removed on completion of the surgery (see Figs. 2.11 and 2.12). 38 39 FIGURE 2.11 Placement of tarsorrhaphy suture. A: A 4-0 silk suture is passed through the skin of the upper eyelid and is directed through the gray line of the upper lid margin. Two methods can be used for placing the tarsorrhaphy suture through the lower eyelid. B: The suture is passed into and out of the gray line in a single pass without exiting the skin. The suture should be passed deep enough to get a good bite of the inferior tarsus to prevent it from being pulled out. C and D: An alternative method using a horizontal mattress suture in which the needle is passed from the superior portion of the lower eyelid (gray line) out of the skin, and back again. The final pass of the suture is through the gray line of the upper eyelid, exiting the skin. Either technique works well. 40 FIGURE 2.12 A: The tarsorrhaphy suture should not be tied tightly but should be left with some space between the knot and the skin of the upper eyelid because it may be necessary to open the palpebral fissure slightly during the surgery to examine the eye and/or to perform forced duction tests (B). C: A hemostat can be used to grasp the tarsorrhaphy suture to apply traction to the lower eyelid during incision and dissection. STEP 2. Identification and Marking of the Incision Line The incision for a subciliary approach is made approximately 2 mm inferior to the lashes, along the entire length of the eyelid (see Fig. 41 2.13A). The incision may be extended laterally approximately 2 cm past the lateral canthus without damaging the anterior temporal branch of the facial nerve (which crosses the zygomatic arch at 3 cm from the canthus) preferably in a natural crease. If a natural skin crease is not obvious, the extension can usually be made straight laterally or slightly inferolaterally. 42 43 FIGURE 2.13 Subciliary incision being made. A: The incision is approximately 2 mm below the eyelashes and can be extended laterally as necessary (top dashed line). It is made through skin only. B: A Freer elevator or a cotton-tipped applicator stick can be used to lift the lower eyelashes to prevent them from being injured during the incision. STEP 3. Vasoconstriction Ideally, the incision line is inked before infiltration of a vasoconstrictor. Tissues distort after infiltration and a perceptible crease may disappear following the injection. If the eyelid is swollen and creases are effaced, consider an injection of hyaluronidase (150 U) mixed in 30 mL of local anesthesia with a vasoconstrictor. Dilute epinephrine solutions not only aid in hemostasis but can also separate the tissue planes before the incision, thereby facilitating incision in the thin eyelids. STEP 4. Skin Incision The depth of the initial incision is through the skin only. The underlying muscle should be visible when the skin is incised completely (Fig. 2.13A and B). 44  STEP 5. Subcutaneous Dissection Subcutaneous dissection toward the inferior orbital rim proceeds for a few millimeters using sharp dissection with a scalpel or scissors. The tissue should be tented “up” rather than pulled “back” to avoid dehiscence (see Figs. 2.14 and 2.15). The tarsorrhaphy suture is used to retract the lower eyelid superiorly to assist in the dissection. The skin should be separated from the pretarsal portion of the orbicularis oculi muscle along the entire extent of the incision. Approximately 4 to 6 mm of subcutaneous dissection is adequate. 45 FIGURE 2.14 A: Subcutaneous dissection of skin, leaving pretarsal portion of orbicularis muscle attached to the tarsus. B and C: Dissection 4 to 6 mm inferiorly in this plane is adequate. 46 FIGURE 2.15 Sagittal plane through the orbit and globe demonstrating the subcutaneous dissection of the lid margin. 47 FIGURE 2.16 A and B: Use of scissors to dissect through orbicularis oculi muscle over lateral orbital rim to identify periosteum. STEP 6. Suborbicularis Dissection Scissors with slightly blunted tips are used to dissect through the orbicularis oculi muscle (by spreading in the direction of the muscle) to the periosteum overlying the lateral orbital rim (see Fig. 2.16A and B). Initially, the muscle is dissected over the bony rim because this area is always anterior to the septum orbitale. Limited supraperiosteal dissection in this submuscular plane, over the anterior edge of the infraorbital rim, produces a perfect pocket to cleanly dissect superficial to the septum orbitale. Scissors are used to spread upward in this pocket into the lower eyelid, with the upper tine of the scissors directly beneath the “step” incision and the lower tine over the orbital rim (see Figs. 2.17 and 2.18). In this plane between the orbicularis oculi muscle and the orbital septum, the convexity of the curved scissors faces outward. FIGURE 2.17 A and B: Dissection between orbicularis oculi 48 muscle and orbital septum. The dissection should extend completely along the orbital rim and superiorly to the level of subcutaneous dissection. 49 FIGURE 2.18 Sagittal plane through orbit showing the level and extent of dissection. Note the bridge of orbicularis oculi muscle remaining between the lid and skin–muscle flap. STEP 7. Incision Between Pretarsal and Preseptal Portions of Orbicularis Oculi Muscle An attachment of the orbicularis oculi muscle will remain, extending from the tarsal plate to the skin–muscle flap, which was just elevated from the orbital septum (see Fig. 2.19). This muscle is now incised with scissors placed inferior to the level of the initial skin incision (see Fig. 2.20). 50 FIGURE 2.19 A and B: Incision through the bridge of the orbicularis oculi muscle. 51 FIGURE 2.20 Sagittal plane through orbit showing incision of the bridge of orbicularis oculi muscle. 52 FIGURE 2.21 A: Photograph showing retraction of the flap in preparation for periosteal incision. Note that the orbital septum is intact. B: Incision through periosteum along anterior maxilla, 3 to 4 mm inferior to infraorbital rim. Note that the pretarsal muscle is still remaining on the inferior tarsus and the orbital septum, which restricts the orbital fat from entering the field (C). STEP 8. Periosteal Incision Once the skin–muscle flap of tissue is elevated from the lower eyelid, it can be retracted inferiorly, extending below the inferior orbital rim (see Fig. 2.21A). If the orbital septum is not violated, the tarsal plate above it should be visible with the pretarsal portion of orbicularis oculi still attached and with the orbital septum below extending to the infraorbital rim. An incision can be made with a scalpel through the periosteum on the anterior surface of the maxilla and zygoma, 3 to 4 mm below or lateral to the orbital rim (Fig. 2.21B and C). The incision through the periosteum at this level avoids the insertion of the orbital septum along the orbital margin. The infraorbital nerve is approximately 5 to 7 mm 53 inferior to the orbital rim and should be avoided when the periosteal incision is made. STEP 9. Subperiosteal Dissection of Anterior Maxilla and/or Orbit The sharp end of a periosteal elevator is pulled across the full length of the periosteal incision to separate the incised edges. Periosteal elevators are then used to strip the periosteum from the underlying osseous skeleton, both along the anterior surface of the maxilla and zygoma and inside the orbit. The inferior orbital rim is superior to the orbital floor just behind it. After the periosteum of the infraorbital rim is elevated (see Fig. 2.22A), the elevator is positioned vertically, stripping inferiorly as it proceeds posteriorly for the first centimeter or so (Fig. 2.22A–D). The bony origin of the inferior oblique muscle (the only muscle in the orbit that does not arise from its apex) will be stripped during the subperiosteal dissection. The muscle arises from the floor of the medial orbit just posterior to the orbital rim and lateral to the upper aperture of the nasolacrimal canal and may also arise partly from the lacrimal fascia over the lacrimal sac (see Fig. 2.23). During dissection, one will readily encounter the inferior orbital fissure. The periosteum of the orbit (periorbita) sweeps downward into the fissure. When indicated for exposure, the contents of the inferior orbital fissure may be safely incised after bipolar cautery (see Fig. 2.24A and B). Superior retraction of the orbital contents exposes the orbital floor and walls, as well as the anterior maxilla (see Fig. 2.25). 54 55 56 FIGURE 2.22 A: Photograph showing elevation of periosteum over the top of the infraorbital rim. Frontal (B) and sagittal (C) illustrations showing subperiosteal dissection of anterior maxilla and orbital floor. Note that the periosteal elevator entering the orbit is placed almost vertically (D) as dissection proceeds behind the rim. In the anterior region, the floor of the orbit is at a lower level than the crest of the rim, necessitating dissection inferiorly just behind the crest of the rim. 57 FIGURE 2.23 Anatomic dissection showing the position of the inferior oblique muscle (*). It should not be directly visualized if one stays in the subperiosteal plane because its origin will be stripped from the orbital floor along with the periosteum. FIGURE 2.24 A: Anatomic dissection showing incision through the contents of the inferior orbital fissure to facilitate orbital dissection. These tissues should first be cauterized with bipolar 58 electrocoagulation to prevent bleeding when incised. B: Anatomic dissection showing increased exposure of the orbit after incision of contents of the inferior orbital fissure. 59 FIGURE 2.25 Photograph showing the internal orbit after dissection. STEP 10. Closure Closure is usually performed in two layers: the periosteum and the skin (see Fig. 2.26A). Periosteal resorbable sutures ensure that the soft tissues stripped from the anterior surface of the maxilla and zygoma are repositioned anatomically (Fig. 2.26B). Suturing of the orbicularis oculi muscle is unnecessary unless it has been cut vertically or stripped excessively over the zygomatic prominence. Resorbable sutures may be inserted laterally, where the incised orbicularis oculi muscle is thicker (see Fig. 2.27). A 6-0 nonresorbable or fast-resorbing suture is then run along the skin margin. STEP 11. Suspensory Suture for Lower Eyelid Any incision or laceration used to gain access to the infraorbital rim and orbital floor may shorten the lower eyelid vertically during healing. Skin and septal scarring may be beneficially counteracted by superior support of the lower eyelid for several days (or until gross edema has resolved) after surgery. The simplest method is to run a suture through the gray line 60 of the lower eyelid, which is taped to the forehead (see Fig. 2.28). This lifts and supports the lower eyelid in a lengthened position while eyelid edema dissipates. To eliminate suture slippage during functional postoperative forehead motion, a first layer of tape is applied to the skin. The suture is positioned over the first layer and a second tape is applied over it. The suture is folded over this second tape and a third strip of tape is applied over the suture and the other two strips. Vision may be checked by opening the upper eyelid. The entire anterior surface of the globe can be examined by simply removing the tape from the forehead and opening both eyelids. 61 FIGURE 2.26 A and B: Closure of the periosteum with interrupted resorbable sutures. 62 FIGURE 2.27 Photograph showing closure with running 6-0 nonresorbable suture. 63 FIGURE 2.28 Lower-eyelid suspensory suture placed at completion of surgery. The suture is placed through the gray line of the lower eyelid, into the tarsus, and then exits the gray line at approximately 5 mm from the point where it entered (A). It is important to engage some of the tarsal plate to prevent the suture from being pulled out. It is taped to the forehead in the manner shown to provide firm suspension (B and C). The suspension suture does not engage the upper eyelid, leaving it free to permit examination of the eye (D). Technique for Subtarsal Approach The technique for the subtarsal approach has many of the same maneuvers as that described for the subciliary approach, such as protection of the globe, vasoconstriction, and dissection of the orbit. Only those salient points that are different from the ones just described for the subciliary approach are presented here (Video 2.2). Identification and Marking of the Incision Line The skin incision for the subtarsal approach is approximately at the level of the inferior margin of the lower tarsus, in the subtarsal fold. In practice, however, it is made in a natural skin crease in the middle of the lower eyelid (see Fig. 2.29). Although the final scar in this location may be slightly more perceptible than the subciliary incision, clinical 64 investigations reveal a lower incidence of scleral show and ectropion with this approach (5,6). 65 FIGURE 2.29 Photograph showing resting skin tension lines around the eyelids. Any one of these tension lines can be chosen for incision placement, or an incision can be made parallel to them. The skin creases around the orbit should be evaluated carefully (see Fig. 2.30A). If the tissue is swollen, the skin of the opposite orbit may be used to assess and to appreciate the direction of creases. Usually, the crease tails off inferiorly as it extends laterally (Fig. 2.29). If access to the orbital floor and inferior orbital rim are all that is necessary, the subtarsal incision is satisfactory and will result in an imperceptible scar. Extension of the mid-eyelid incision follows the natural crease and never deviates superiorly toward the eyelid margin. The incision line is marked before infiltration of a vasoconstrictor (Fig. 2.30B). Skin Incision The initial incision is through skin and muscle, to the depth of the orbital septum (Fig. 2.30C and D). The incision extends laterally just past the bone of the lateral orbital rim. The skin–muscle flap is then elevated from the orbital septum as dissection proceeds inferiorly. Any remaining orbicularis muscle is dissected at the level of the orbital septum with 66 scissors in a spreading motion and is then incised (Fig. 2.30E and F). Suborbicularis Dissection Scissors with slightly blunted tips are used to dissect between the orbicularis oculi muscle and the orbital septum (Fig. 2.30G and H). A double skin-hook is used to retract the incised lower eyelid skin–muscle flap, and dissection proceeds in this submuscular plane inferiorly along the lateral rim, over the anterior edge of the infraorbital rim (Fig. 2.30I). The incision through the periosteum (Fig. 2.30J and K), the dissection of the orbit (Fig. 2.30L), and closure (Fig. 2.30M–Q) are the same as described for the subciliary approach. 67 68 69 FIGURE 2.30 Subtarsal approach to the orbit. A: Photograph prior to incision demonstrating the natural eyelid creases for this patient. B: Incision marked. C: Illustration and (D) photograph showing the incision being made. E: Scissors dissecting orbicularis oculi muscle laterally along the orbital rim, just superficial to the orbital septum. F: Scissors incising the orbicularis oculi muscle. G: Illustration 70 showing the level of dissection. H: Scissors dissecting inferiorly toward the infraorbital rim. I: Appearance after the skin–muscle flap has been elevated to the infraorbital rim (S, orbital septum; OO, orbicularis oculi muscle). J: Illustration showing elevation of the skin–muscle flap and incision through the periosteum along the anterior maxilla just below the orbital rim. K: Incision through the periosteum being made with electrocautery. L: Dissection into the orbit. M: Resorbable suture being passed through the periosteum on both sides of the incision. N: Appearance after periosteal closure. O: Resorbable suture (knot buried) passed through orbicularis oculi muscle on each side of incision. P: Appearance after orbicularis oculi muscle sutures placed. Q: Final closure with running 6-0 fast absorbing catgut suture. Alternative Technique: Extended Lower Eyelid Approach The extended lower eyelid approach provides access to the entire lateral orbital rim to a point approximately 10 to 12 mm superior to the frontozygomatic suture (7). Although less direct, this access may substitute for the lateral brow or upper eyelid approaches. For unrestricted exposure, the lateral canthal tendon must be stripped from its insertions and subsequently repositioned. This approach is useful when the entire lateral orbit, lateral orbital rim, orbital floor, and inferior orbital rim have to be accessed. The incision for the extended subciliary approach is exactly the same as that described for the standard subciliary incision, but the incision must be extended laterally by approximately 1 to 1.5 cm in a natural crease (Fig. 2.13). If no natural skin crease extends laterally from the lateral palpebral fissure, the extension can usually be made straight laterally, or slightly inferolaterally. The subtarsal approach does not lend itself to this extended dissection because the incision is placed more inferiorly than the subciliary incision, especially laterally where the dissection up the lateral orbital rim proceeds. Supraperiosteal dissection of the entire lateral orbital rim is performed with scissors dissection to a point above the frontozygomatic suture (see Fig. 2.31). The orbicularis oculi musculature and the superficial portion of 71 the lateral canthal tendon are retracted superiorly. The periosteum is then incised in the middle of the lateral orbital rim from the superior extent downwards, connecting to the standard infraorbital rim incision (see Fig. 2.32). Subperiosteal dissection strips the tissues from the orbital floor and lateral orbital wall, including insertions of the deep component of the lateral canthal tendon, Lockwood suspensory ligament, and the lateral check ligament from the orbital (Whitnall) tubercle of the zygoma. The frontozygomatic suture is readily exposed (see Fig. 2.33). 72 FIGURE 2.31 Technique used to obtain increased exposure of the lateral orbital rim. The initial incision is extended laterally 1 to 1.5 cm, and supraperiosteal dissection along the lateral orbital rim proceeds superiorly until the area of interest is approached. 73 FIGURE 2.32 Dissection to the level of the frontozygomatic suture. The tissues superficial to the periosteum are retracted superiorly with a small retractor and an incision through periosteum is made 3 to 4 mm lateral to the lateral orbital rim. Subperiosteal dissection exposes the entire lateral orbital rim. Dissection into the lateral orbit frees the tissues and allows retraction superiorly. 74 75 76 FIGURE 2.33 Photographs after “extended” subciliary approach. A: Entire lateral orbital rim exposed to a level above the frontozygomatic suture. B: Orbital floor exposure (fractured). C: Lateral orbital wall (greater wing of sphenoid and zygoma) exposed. Isolated lateral canthopexy is not necessary if careful repositioning and suturing of the periosteum along the lateral orbital rim are accomplished. This maneuver brings the superficial portion of the lateral canthal tendon into proper position, giving the lateral palpebral fissure a satisfactory appearance. REFERENCES 1. Zide BM, Jelks GW. Surgical anatomy of the orbit. New York: Raven Press; 1985. 2. Anderson RC. The medial canthal tendon branches out. Arch Ophthalmol. 1977;95:2051. 3. Zide BM, McCarthy JG. The medial canthus revisited. An anatomical basis for canthopexy. Ann Plast Surg. 1983;11:1. 4. Rodriguez RL, Zide BM. Reconstruction of the medial canthus. Clin Plast Surg. 1988;15:255. 5. Holtmann B, Wray RC, Little AG. A randomized comparison of four incisions for orbital fractures. Plast Reconstr Surg. 1981;67:731. 6. Bahr W, Bagambisa FB, Schlegel G, et al. Comparison of transcutaneous incisions used for exposure of the infraorbital rim and orbital floor: a retrospective study. Plast Reconstr Surg. 1992;90:585. 7. Manson PN, Ruas E, Iliff N, et al. Single eyelid incision for exposure of the zygomatic bone and orbital reconstruction. Plast Reconstr Surg. 1987;79:120. 77  3 Transconjunctival Approaches Transconjunctival approaches expose the floor of the orbit and infraorbital rim. More recently, these approaches have been extended medially to expose the medial wall of the orbit. The significant advantage of transconjunctival approaches is that the scar is hidden in the conjunctiva. If a canthotomy is performed in conjunction with the approach, the only visible scar is the lateral extension, which heals leaving an inconspicuous scar. Transconjunctival techniques are rapid because neither skin nor muscle dissection is necessary. These simple techniques, however, demand surgical precision in execution because the complication of improper transconjunctival technique (i.e., entropion) is much more difficult to correct than the sequela of an improper skin incision (i.e., ectropion). Another advantage of the transconjunctival approach is that the medial extent of the incision can be expanded superiorly, behind the lacrimal drainage system, as high as the levator aponeurosis. This approach has been called the transcaruncular because of the incision’s relation to the caruncle. This approach can be useful when access to the medial orbital wall is required. This chapter will discuss both approaches because they are often combined in practice. 78 Transconjunctival Approach to the Infraorbital Rim and Floor of the Orbit The traditional transconjunctival incision, also called the inferior fornix incision, is a popular approach for exposing the orbital floor and infraorbital rim. Both preseptal and retroseptal approaches have been described. These approaches vary in the relation of the orbital septum to the path of dissection (see Fig. 3.1). The retroseptal approach is more direct than the preseptal approach and is easier to perform. An additional advantage is that there is no dissection within the eyelid, which may help avoid scarring within it. The periorbital fat may be encountered during the retroseptal approach, but this is of little concern and causes no ill effects. A lateral canthotomy enhances exposure and is frequently employed. The retroseptal transconjunctival approach with a lateral canthotomy is described in this chapter (Video 3.1). 79 FIGURE 3.1 Sagittal section through orbit showing preseptal and retroseptal placement of incision. 80 Surgical Anatomy Lower Eyelid In addition to the anatomy described in Chapter 2, for the lower eyelid approach, the transconjunctival approach to the infraorbital rim and orbital floor requires the comprehension of other points. Lower Eyelid Retractors During full downward gaze, the lower eyelid descends approximately 2 mm in conjunction with the movement of the globe itself. The inferior rectus muscle, which rotates the globe downward, simultaneously uses its fascial extension to retract the lower eyelid. This extension, which arises from the inferior rectus, contains sympathetic-innervated muscle fibers and is commonly called the capsulopalpebral fascia (see Fig. 3.2). Incision of this fascial sheet is clinically inconsequential when closure of the incision is correctly achieved. 81 FIGURE 3.2 Sagittal section through orbit and globe. C, palpebral conjunctiva; IO, inferior oblique muscle; IR, inferior rectus muscle; LLR, lower lid retractors; OO, orbicularis oculi muscle; OS, orbital septum; P, periosteum/periorbita; TP, tarsal plate. 82 Technique STEP 1. Vasoconstriction A vasoconstrictor is injected under the conjunctiva to aid in hemostasis (see Fig. 3.3A). Additional solution is infiltrated during the lateral canthotomy (Fig. 3.3B). FIGURE 3.3 Photographs showing delivery of small amounts of local anesthetic with a vasoconstrictor, under the conjunctiva (A) and in the area of the lateral canthotomy (B). STEP 2. Protection of the Globe Because tarsorrhaphy is precluded with this approach, a corneal shield should be placed to protect the globe (see Fig. 3.4). STEP 3. Traction Sutures in the Lower Eyelid The lower eyelid is everted with fine forceps and two or three traction sutures are placed through the eyelid (Fig. 3.4). These sutures should be placed straight through the eyelid, from palpebral conjunctiva to skin, approximately 4 to 5 mm below the eyelid margin to ensure that the tarsal plate is included in the suture. 83 FIGURE 3.4 Placement of a corneal protector (shield). Two or three traction sutures placed through the lower eyelid assist in the placement of the shield and in subsequent surgery. FIGURE 3.5 Illustration (A) and photograph (B) of initial incision for lateral canthotomy. 84  STEP 4. Lateral Canthotomy and Inferior Cantholysis When a lateral canthotomy is indicated, the canthotomy is the initial incision. One tip of the pointed scissors is inserted within the palpebral fissure, extending laterally to the depth of the underlying lateral orbital rim (approximately 7 to 10 mm). The scissors are used to cut horizontally through the lateral palpebral fissure (see Fig. 3.5). The structures that are cut in the horizontal plane are the skin, orbicularis oculi muscle, orbital septum, lateral canthal tendon, and conjunctiva. The traction sutures are used to evert the lower eyelid. The lower eyelid is still tethered to the lateral orbital rim by the inferior limb of the lateral canthal tendon (see Fig. 3.6A). This tethering functionally adapts the lower eyelid tightly to the globe (Fig. 3.6B). The tendon, which is easily visualized with eyelid retraction, is released with a sharp vertical cut. To perform the cantholysis, the scissors must be positioned with a vertical orientation (see Fig. 3.7). After cantholysis (see Fig. 3.8A), the lower eyelid is immediately freed from the lateral orbital rim (Fig. 3.8B), making the eversion more effective. FIGURE 3.6 A: Anatomic dissection showing result after initial canthotomy illustrated in Figure 3.5. Note that the inferior limb of the lateral canthal tendon (*) is still attached to the lower tarsus, preventing mobilization. The lower eyelid is still tightly adapted to the eyeball (B). 85 FIGURE 3.7 Illustration (A) and photograph (B) showing technique of inferior cantholysis. STEP 5. Transconjunctival Incision After the lower eyelid is everted, the position of the lower tarsal plate through the conjunctiva is noted. One of two following techniques can be used to incise the conjunctiva. In the first technique, blunt-tipped pointed scissors are used to dissect through the small incision in the conjunctiva made during the lateral canthotomy, inferiorly toward the infraorbital rim. Traction sutures are used to evert the lower eyelid during the dissection. The scissors are spread to clear a pocket posterior to the orbital septum, ending just posterior to the orbital rim (see Fig. 3.9). 86 FIGURE 3.8 A: Anatomic dissection showing result after inferior cantholysis illustrated in Figure 3.7. Note that the inferior limb of the lateral canthal tendon (*) has been severed, allowing the lower eyelid great mobility (B). FIGURE 3.9 Illustration (A) and photograph (B) showing how the scissors are placed into the initial canthopexy incision to dissect in the subconjunctival plane. The dissection should be just below the tarsal plate and should extend no farther medially than the lacrimal punctum. Note how the traction sutures through the lower eyelid assist in this dissection. Scissors are used to incise the conjunctiva and lower eyelid retractors midway between the inferior margin of the tarsal plate and the inferior conjunctival fornix (see Fig. 3.10). The incision can be extended as far medially as necessary for the surgery but must not violate the lacrimal 87 sac. The incised edge of the vestibular conjunctiva can be dissected free (see Fig. 3.11), providing a location for a traction suture to hold the corneal shield in place (see Fig. 3.12). 88 FIGURE 3.10 Illustration (A) and photograph (B) showing incision of the conjunctiva below the tarsal plate. C: Sagittal plane through the orbit and globe demonstrating the level and plane of incision. The conjunctiva and lower eyelid retractors are incised with scissors. 89 FIGURE 3.11 The incised edge of the vestibular conjunctiva is dissected free so that a traction suture can be placed. FIGURE 3.12 A: Illustration showing incision through the 90 periorbita. Small retractors are placed so that the lower eyelid is retracted to the level of the anterior surface of the infraorbital rim. A broad retractor is placed just posterior to the infraorbital rim, confining the orbital fat. The Jaeger Lid Plate (Jaeger Lid Plates— Anthony Products, Inc., Indianapolis, IN) is a clear plastic retractor (B) that works well for retracting the orbital contents because it is transparent. The incision is made through the periosteum just posterior to the infraorbital rim with either a scalpel or electrocautery (C). FIGURE 3.13 Photographs showing another method of incising the conjunctiva. With the lower eyelid retracted anteriorly, a fine-tipped electrocautery is used to incise the conjunctiva (A). (In this instance, a lateral canthotomy was not performed.) Once the conjunctiva is incised (B) (white arrows), the electrocautery is used to incise the lower eyelid retractors and periorbita (black arrow). STEP 6. Periosteal Incision After retracting the orbital contents internally and the lower eyelid externally, using suitable retractors, the periorbita is sharply incised, avoiding the lacrimal sac medially (Fig. 3.12). During the retroseptal approach, the incision through the periorbita is immediately posterior to the orbital rim. An alternate method of incising the conjunctiva, lower eyelid retractors, and periorbita incorporates retracting the lower eyelid anteriorly, inserting small retractors, and cutting directly through these structures with a needle-tipped electrocautery (see Fig. 3.13). 91  STEP 7. Subperiosteal Orbital Dissection Periosteal elevators are used to strip the periosteum over the orbital rim and anterior surface of the maxilla and zygoma, and the orbital floor (see Fig. 3.14). A broad malleable retractor should be placed as soon as feasible to protect the orbit and to confine any herniating periorbital fat. FIGURE 3.14 Subperiosteal dissection of the orbital floor. Note the traction suture placed through the cut end of the conjunctiva (A), which assists in retracting the conjunctiva and maintains the corneal shield in place. B: Photograph showing use of periosteal elevator to strip the periosteum from the orbital floor. Note the clear retractor used to elevate the tissues. STEP 8. Closure Periosteal suturing is not mandatory but optional, if exposure permits. Before closing the conjunctiva, an inferior canthopexy suture is inserted but not tied (see Fig. 3.15). Delaying the tying of this suture allows open access to the conjunctiva for its closure. If the conjunctiva were to be closed first, the sutures might tear through the delicate tissue during the inferior canthopexy. A 4-0 polyglactin or other long-lasting suture is used to reattach the 92 lateral portion of the inferior tarsal plate to the residual superior portion of the lateral canthal tendon or to the fixed surrounding tissues. This suture should be securely located in the appropriate anatomic location so that the lateral canthal area appears symmetrical to the contralateral eye and the eyelid is adjacent to the globe. When the inferior limb of the canthal tendon is initially severed during the approach, only a minute amount of canthal tendon remains attached to the lower tarsus. Therefore, the canthopexy anchor suture may be inserted through the lateral border of the tarsus only when the tendon is inadequate to retain a suture. The suture through the lateral border of the lower tarsus and/or cut portion of the lateral canthal tendon may be facilitated by elevating the skin sharply with a blade, slightly atop the canthus or tarsal plate. This is easily performed by using a no. 15 scalpel to incise between the tarsus and the skin. A cleavage plane exists in this location, and the tissue readily separates. The tarsus is grasped with forceps and a suture is passed through either the cut tendon or the lateral border of the tarsus in such a manner that a firm bite of tissue is engaged (Fig. 3.15A and B). After a good bite of the lower tarsus has been secured with the suture, the suture needle is inserted through the superior limb of the lateral canthal tendon and/or the periosteum of the lateral orbital rim in the vertex of the palpebral fissure. The bulk of the lateral canthal tendon attaches to the orbital tubercle, 3 to 4 mm posterior to the orbital margin. Following canthotomy, the superior limb of the canthal tendon is still attached to the orbital tubercle. The suture should be inserted as deeply behind the orbital rim as possible to adapt the lower eyelid to the globe. If the suture is not properly placed, the eyelid will not contact the globe laterally, and will give an unnatural appearance. Therefore, the suture needle should be passed far posteriorly and superiorly to ensure that it grasps the superior limb of the tendon. An effective method is to first identify the superior limb of the canthal tendon by placing a small, toothed forceps within the incision (Fig. 3.15C). The forceps is then passed along the medial side of the lateral orbital rim for a few millimeters until the dense fibers of the superior limb are located. While the tendon is being held, the suture needle should be passed through the tendon (Fig. 3.15D). The two ends of the suture should be pulled to ensure that the suture is firmly attached, or pexed, to ligamentous tissue. The suture should be left untied until the conjunctiva has been closed (Fig. 3.15E). 93 94 95 96 97 98 99 FIGURE 3.15 A: Closure of transconjunctival incision and inferior canthopexy. The inferior canthopexy suture is placed (upper inset). B: A suture has been placed through the cut edge of the tarsal plate of the lower eyelid. C: Forceps are used to identify the superior portion of the lateral canthal tendon. D: The suture is placed through the superior canthal tendon. E: The suture is not tied but left lax. F: Closure of the conjunctiva and lower eyelid retractors G: Appearance after closure of the conjunctiva and just prior to tying the inferior canthopexy suture. H: Appearance after canthopexy tied. Note the normal appearance to the lateral aspect of the palpebral fissure. I: Separation of the tissues with cotton- tipped applicators shows the lower eyelid reapproximated. J: Skin sutured. The conjunctiva should be closed with a running 6-0 chromic gut suture (Fig. 3.15F and G). The ends of the suture may be buried. No attempt should be made to reapproximate the lower eyelid retractors because they are in intimate contact with the conjunctiva and will be adequately repositioned when that layer is closed. The inferior canthopexy suture is then tightened and tied, drawing the lower eyelid into position (Fig. 3.15H and I). Finally, subcutaneous sutures and 6-0 skin sutures are placed along the horizontal lateral canthotomy (Fig. 3.15J). Alternative Technique: Extended Transconjunctival Approach for Exposure of the Frontozygomatic Area The extended transconjunctival approach provides access to the entire lateral orbital rim to a point approximately 10 to 12 mm superior to the frontozygomatic suture. For this added exposure, however, a more generous lateral canthotomy incision and wider undermining are needed. Additionally, the superior limb of the lateral canthal tendon must be stripped from its insertions. The approach is useful when access to the entire lateral orbit, lateral orbital rim, orbital floor, and inferior orbital rim is required. 100  The incision for the extended transconjunctival approach is exactly as described for the standard transconjunctival approach, but the incision must be extended further laterally, 1 to 1.5 cm in a natural crease. If no natural skin crease extends laterally from the lateral palpebral fissure, the extension can usually be made straight laterally or slightly superolaterally. Supraperiosteal dissection of the entire lateral orbital rim is performed to a point above the frontozygomatic suture. The orbicularis oculi musculature and superficial portion of the lateral canthal tendon are retracted as the dissection proceeds. After retraction, the periosteum is incised in the middle of the lateral orbital rim from the highest point obtained with supraperiosteal dissection. The periosteal incision extends to the one described from the standard approach to the orbital floor and infraorbital rim. Subperiosteal dissection should strip all the tissues from the orbital floor and the lateral orbital wall. Generous subperiosteal dissection made deep into the lateral orbit allows retraction of these tissues to expose the frontozygomatic suture (see Fig. 3.16). This extent of exposure and release demands meticulous closure, with anatomical resuspension of tissues and the lateral canthus within the orbit. FIGURE 3.16 Photographs showing the amount of exposure that can be attained from the extended transconjunctival approach. A: Exposure of the orbital floor. B: Exposure of the lateral wall of the orbit, as well as the frontozygomatic suture. Transconjunctival (or Transcaruncular) Approach to the Medial Orbit 101 The medial wall of the orbit can be approached through the conjunctiva on the nasal side of the globe. This approach has been most commonly called the “transcaruncular” approach because the caruncle is traversed with the initial incision. Others, however, place the incision just temporal to the caruncle. There are no vulnerable structures in the medial orbit with the transcaruncular approach from the 11:00 position of the globe of the left eye where the trochlea and levator aponeurosis are encountered to the 6:00 position where the inferior oblique muscle is encountered. Therefore, even though the initial access incision may only be 12 mm, access may be extended subperiosteally to the orbital roof and the infraorbital rim (Video 3.2). The advantage of the transconjunctival approach to the medial orbit is avoiding a local skin incision or a coronal approach to reach this area. The access provided is satisfactory for most reconstructive procedures. By extending the transconjunctival incision along the floor of the orbit, complete exposure of the medial wall, floor, and lateral wall of the orbit is possible through a single incision. Surgical Anatomy The anatomy of the medial aspect of the orbit underlying the transcaruncular approach is complex but most of it can be avoided when the dissection is executed properly. The medial canthal tendon is the centerpiece of medial canthal anatomy. It has an elastic lateral portion that supports the lacrimal canaliculi and then splits into anterior, superior, and posterior limbs, all of which blend with the lacrimal sac fascia (see Chapter 2). The preseptal portion of the orbicularis oculi muscle has a superficial head and a deep head. The superficial head originates from the anterior limb of the medial canthal tendon. The deep head originates from the fascia of the lacrimal sac. The pretarsal portion of the orbicularis oculi muscle sends anterior fibers to the anterior portion of the medial canthal tendon and posterior fibers that line the posterior wall of the lacrimal sac to insert on the posterior lacrimal crest (lacrimal bone) (see Fig. 3.17). These posterior fibers form an especially important structure known as the pars lacrimalis or Horner muscle and ensure proper posterior apposition of the eyelid to the globe. Disruption of Horner muscle might allow the medial eyelid to fall anteriorly away from the globe. 102  Between the anterior and posterior limbs of the medial canthal tendons lies the lacrimal sac into which tears drain from the canaliculi. This region is known as the lacrimal sac fossa and is bordered by the bony anterior and posterior lacrimal crests (Fig. 3.17). Inferiorly, the fossa is contiguous with the bony nasolacrimal duct. Superiorly, the lacrimal sac extends just slightly above the medial canthal tendon. 103 FIGURE 3.17 Illustration showing the relation of the periosteal incision of the orbit (dashed line), the osteology, the edges of the eyelids, the lacrimal drainage system, and Horner muscle (arrows). The incision through the periosteum is posterior to all the structures shown. 104  Surface anatomy is especially important in the transcaruncular approach to the medial orbit (see Fig. 3.18). The plica semilunaris (semilunar fold) is a narrow, highly vascularized, crescent-shaped fold of the medial conjunctiva. Its lateral border is free and is separated from the bulbar conjunctiva. The caruncle is a small, fleshy, keratinized mound of sebaceous tissue attached to the inferomedial side of the plica semilunaris. Just medial to it lies the common canaliculus. A condensation of fascia exists deep to the caruncle. It is continuous with the medial canthal ligament, and serves as the anterior insertion for several structures, including Horner muscle, the medial orbital septum, the medial capsulopalpebral muscle, and the anterior Tenon capsule. Horner muscle and the medial orbital septum insert into the periorbita immediately posterior to the posterior lacrimal crest. The anatomic plane in which these fascial extensions lie is a potential region for surgical dissection that avoids the medial rectus muscle posteriorly and laterally and the lacrimal drainage system anteriorly and medially. An incision made through the caruncle and this dense fibrous condensation passes along a natural plane just posterior to Horner muscle, which buffers this safe and bloodless plane from the lacrimal sac. 105 106 107 108 FIGURE 3.18 Illustration (A) and photograph (B) showing the surface topography of the eye. The “*” is the location of the caruncle. The arrows indicate the position of the semilunar fold. C: Forceps are grasping the caruncle. D: Forceps are lifting the semilunar fold. The “*” is the location of the caruncle. Technique STEP 1. Vasoconstriction The medial orbit is infiltrated with a vasoconstrictor to facilitate hemostasis. The solution is delivered to the medial orbit through the conjunctiva or through the skin just nasal to the eyelids. The conjunctiva in the area of the caruncle and semilunar fold can be infiltrated, but doing so can distort these structures and make incision location difficult. If one decides to infiltrate the conjunctiva, 7 to 10 minutes should pass to allow the solution to diffuse peripherally. STEP 2. Transconjunctival Incision The upper and lower eyelids are retracted with traction sutures, vein retractors, or Desmarres retractors, taking care to avoid damage to the 109 lacrimal puncta and canaliculi. The globe is retracted laterally by inserting a malleable Jaeger Lid Plate retractor into the medial fornix. This increases the distance between the posterior surface of the eyelids and the globe, facilitating ease of incision. Gentle pressure is given posteriorly on the globe with this retractor to protect the globe from inadvertent incision, flatten the caruncle, increase the visibility of the area of incision, and force the extraconal orbital fat posteriorly in this area. It is important to avoid the semilunar fold, which is lateral to the caruncle. A 12-to 15-mm vertical incision is made through the conjunctiva and lateral one third of the caruncle using Stevens or Westcott scissors (see Fig. 3.19). Alternatively, the incision can be made just temporal to the caruncle. The incision can be made superiorly through the conjunctiva to the level of the levator palpebrae aponeurosis. FIGURE 3.19 Incision through the medial conjunctiva. A: Illustration showing the use of scissors to make the incision. Note the position of the caruncle and semilunar folds in relation to the incision, which is just lateral to the caruncle. B: Photograph showing incision that has been made with needle-point cautery. The forces are grasping and retracting the semilunar fold. The “*” is the position of the caruncle. STEP 3. Subconjunctival Dissection The condensed fibrous layer just deep to the caruncle is dissected in a posteromedial direction, aiming just posterior to the posterior lacrimal crest. Horner muscle provides a natural plane for dissection down to the posterior lacrimal crest, where it inserts. The tips of the curved Stevens scissors (see Fig. 3.20) or a Freer elevator are used to palpate the 110 posterior lacrimal crest. The tips of the instrument can be rolled anteroposteriorly to help identify the posterior lacrimal crest. The dissection should be performed on the posterior side of the posterior lacrimal crest. A malleable retractor or periosteal elevator is held firmly against the medial orbital wall immediately posterior to the posterior lacrimal crest. This establishes the plane of the dissection, which is then performed with scissors. The scissors are spread gently to expose the periorbita immediately posterior to the posterior lacrimal crest. The plane of dissection passes along the posterior aspect of Horner muscle. After the scissors have been spread to expose the medial orbit, a malleable retractor is inserted before removing the scissors. FIGURE 3.20 Dissection deep to the conjunctiva. A: Photograph showing the use of scissors to spread into the conjunctival incision toward the medial orbital wall. The points of the scissors or a Freer elevator (B) can be used to palpate the posterior lacrimal crest to ensure that the dissection is posterior to it and to the Horner muscle. STEP 4. Periosteal Incision and Exposure The periorbita along the posterior lacrimal crest is incised in a superior to inferior direction with a scalpel or a needle cautery, or with a spreading motion of sharp, pointed scissors (see Fig. 3.21). This incision should be just posterior to the insertion of Horner muscle onto the posterior lacrimal crest. Subperiosteal dissection of the medial wall begins with a periosteal elevator. The periorbita is elevated superiorly and inferiorly to obtain a wide anterior aperture. The medial wall of the orbit is exposed from the floor to the roof (see Fig. 3.22). The anterior and posterior ethmoidal arteries are readily identified, cauterized, and cut. A malleable retractor is placed deep along the medial wall and, when retracted, the medial wall is 111 exposed. STEP 5. Closure Closure of the periorbita is not essential and is quite difficult to perform. It is prudent to repair the conjunctiva and the caruncle with 6-0 gut suture to help prevent symblepharon, pyogenic granuloma, and orbital fat prolapse. 112 FIGURE 3.21 Periosteal incision. Illustration (A) and photograph (B) showing the use of scissors to open the periosteum along the medial orbital wall. C: Illustration from within the left orbit facing externally, showing the path of dissection. Note the periosteal incision is made posterior to the Horner muscle. 113 FIGURE 3.22 Exposure of the medial wall of the orbit. A: Illustration demonstrating the path of dissection along the medial orbital wall. Illustration (B) and photograph (C) showing the medial wall exposed. Combining Transconjunctival Approaches The transcaruncular approach can be used for isolated medial orbital wall surgery or combined with a retroseptal transconjunctival approach to the orbital floor (with or without a lateral canthotomy; see preceding text). By so doing, the entire medial wall, medial floor, and lateral wall of the orbit can be exposed. When combined with a transconjunctival approach to the floor of the orbit, lateral canthotomy and inferior cantholysis are done first (see preceding text). The lower eyelid is retracted anteriorly and inferiorly to provide improved access to the medial conjunctival surfaces (see Fig. 3.23A). Scissors are then used to first undermine (Fig. 3.23B) and then to incise the conjunctiva just lateral to the caruncle (Fig. 3.23C). The incision 114 is continued superiorly to the level of the levator aponeurosis (Fig. 3.23D). 115 116 FIGURE 3.23 Photographs showing the medial transconjunctival approach combined with a standard transconjunctival approach to the orbital floor. A: Lateral canthotomy, inferior cantholysis, and incision through the conjunctiva have been performed. Note that the lower eyelid can be retracted anteriorly to provide access to the 117 medial aspect of the fornix. B: Undermining of conjunctiva medial to the globe. C: Incising the conjunctiva just lateral to the caruncle with scissors. D: Extending the conjunctival incision superiorly along the medial aspect of the orbit. During the dissection, the inferior oblique muscle is encountered (see Fig. 3.24A). This muscle can either be stripped from its origin or severed from its bony attachment (Fig. 3.24B). If it is incised, leaving a small amount of muscle still attached to the bone, a single suture can be placed during closure to reapproximate the severed muscle. If it is stripped from its origin, it does not have to be repositioned. One can then continue the incision and dissection superomedially as described earlier in this chapter. 118 FIGURE 3.24 Photographs showing the inferior oblique muscle (A, arrow). Scissors are shown incising this muscle (B). 119  4 Supraorbital Eyebrow Approach Surgical Anatomy The “in the eyebrow” incision offers simple and rapid camouflaged access to the lateral supraorbital rim, the frontozygomatic suture line, and occasionally the region slightly below it. No important neurovascular structures are involved in this approach. If the incision is to be continued along the lateral orbit for more inferior exposure, the incision crosses the resting skin tension lines or crow’s feet perpendicularly; therefore, this option should be avoided. Additionally, cosmetic eyebrow removal restricts this incision for women. For these reasons, the supraorbital eyebrow approach is not recommended, except possibly for men whose fracture lines are high on the lateral orbital rim. The main disadvantages of the approach are the extremely limited access it provides and a scar that is perceptible within the eyebrow or, if extended inferiorly, below it. A previously popular incision used to gain access to the superolateral orbital rim is the eyebrow incision. Apart from the advantage that this approach involves no important neurovascular structures, it gives simple and rapid access to the frontozygomatic area. If the incision is made almost entirely within the confines of the eyebrow, the scar is usually imperceptible. Occasionally, however, there is some hair loss, which makes the scar perceptible. Unfortunately, this approach is undesirable in individuals whose eyebrows are not extended laterally and inferiorly along 120 the orbital margin. Incisions made along the lateral orbital rim outside the eyebrow are very conspicuous in such individuals, for whom another type of incision may be indicated. The main disadvantage of the approach is its extremely limited access (Video 4.1). Technique STEP 1. Vasoconstriction A local anesthetic along with a vasoconstrictor is injected into the subcutaneous tissues over the lateral orbital rim to aid in hemostasis. STEP 2. Skin Incision The eyebrow is not shaved. The skin is straddled over the orbital rim using two fingers, and an incision of 2 cm or longer is made, with the inferior extent of the incision arresting at the end of the eyebrow. The incision is made parallel to the hair of the eyebrow to avoid cutting the hair shafts. The incision is extended up to the depth of the periosteum (see Fig. 4.1). The skin is freely movable in this plane. Access can be improved by extending the incision more anteriorly within the confines of the eyebrow to the supraorbital nerve. Extending the incision inferiorly along the orbital rim should be avoided because the incision would cross the lines of resting skin tension, making the scar very conspicuous. When indicated, extension of the incision inferiorly may utilize a small gentle 90-degree “skin-only” turn into a crow’s foot wrinkle laterally. High extensions must avoid the frontal branch of the facial nerve and low extensions should be at least 6 mm above the level of the lateral canthus. FIGURE 4.1 Illustration showing placement of incision within 121 confines of eyebrow hair (A). The incision is made through the skin and subcutaneous tissues to the level of the periosteum in one stroke. Note that the entire incision is within the confines of the hair of the eyebrow (B). STEP 3. Periosteal Incision After undermining in the supraperiosteal plane, the skin is retracted over the area of interest where a sharp periosteal incision is made (see Fig. 4.2). 122 FIGURE 4.2 Incision through periosteum along lateral orbital rim and subperiosteal dissection into lacrimal fossa. Because of the concavity just behind the orbital rim in this area, the periosteal elevator is oriented laterally as dissection proceeds posteriorly. 123 FIGURE 4.3 Photograph showing the limited extent of exposure provided by this approach when the incision is kept within the confines of the eyebrow. STEP 4. Subperiosteal Dissection of Lateral Orbital Rim and Lateral Orbit Two sharp periosteal elevators are used to expose the lateral orbital rim on the lateral, medial (intraorbital), and if necessary, posterior (temporal) surfaces (Fig. 4.2). Wide undermining of the skin and periosteum allows the tissues to be retracted inferiorly, providing better access to the lower portions of the lateral orbital rim. However, the access provided by this approach is limited (see Fig. 4.3). If one stays within the subperiosteal space, there is virtually no possibility of damaging vital structures. STEP 5. Closure The incision is closed in layers. 124  5 Upper Eyelid Approach The most direct and cosmetically appealing approach to the superolateral orbital rim is the upper eyelid approach, also called upper blepharoplasty, upper eyelid crease, and supratarsal fold approach. In this approach, a natural skin crease in the upper eyelid is used to make the incision (Video 5.1). Surgical Anatomy Upper Eyelid In sagittal section, the upper eyelid consists of at least five distinct layers: the skin, the orbicularis oculi muscle, the orbital septum above or levator palpebrae superioris aponeurosis below, Müller muscle/tarsus complex, and the conjunctiva (see Fig. 5.1). The skin, orbicularis oculi muscle, and conjunctiva of the upper eyelid are similar to those of the lower eyelid (see Chapter 2). The upper eyelid differs from the lower eyelid, however, by the presence of the levator palpebral superioris aponeurosis and Müller muscle. Orbital Septum/Levator Aponeurosis Complex Deep to the orbicularis oculi muscle lies the orbital septum/levator aponeurosis complex. Unlike the situation in the lower eyelid, where the orbital septum inserts into the tarsal plate, in the upper eyelid it extends 125 inferiorly and blends with the levator aponeurosis approximately 10 to 15 mm above the upper eyelid margin. The levator muscle usually becomes aponeurotic at the equator of the globe in the superior orbit. The aponeurosis courses anteriorly to insert onto the anterior surface of the lower two thirds of the tarsal plate. Extensions of the levator aponeurosis also extend anteriorly into the skin of the lower portion of the upper eyelid. The aponeurotic portion of the levator behind the orbital septum is much wider than the muscle from which it is derived, and its medial and lateral extensions are known as horns or cornua. The lateral horn of the levator is prominent and deeply indents the anterior portion of the lacrimal gland to divide it into thin palpebral and thick orbital portions; its lateral extension attaches to the orbital wall at the orbital (Whitnall) tubercle. The weaker medial horn of the levator aponeurosis blends with the orbital septum and the medial check ligament. Müller Muscle/Tarsus Complex Deep to the levator aponeurosis the Müller muscle lies superiorly while the tarsus lies along the eyelid margin. Müller muscle is a nonstriated, sympathetically innervated elevator of the upper eyelid. It originates from the inner surface of the levator aponeurosis and inserts onto the superior surface of the upper tarsal plate. The tarsal plate of the upper eyelid is a thin, pliable fibrocartilaginous structure that gives form and support to the upper eyelid. Embedded within the tarsal plate are large sebaceous glands —the tarsal or Meibomian glands. The edge of the tarsus adjacent to the free border of the eyelid is parallel to it, whereas the deeper (superior) border is curved such that the tarsus is somewhat semilunar in shape. It is also curved to conform to the outer surface of the eyeball. The superior tarsus is considerably larger than the inferior tarsus, the greatest height of the superior tarsus being approximately 10 mm and that of the inferior tarsus being approximately 4 to 5 mm (see Fig. 2.6A and B). The tarsal glands sandwiched between the layers of fibrocartilage in the upper eyelid exit on the eyelid margin near the eyelash follicles. The eyelashes are supported by their roots, attached to fibrous tissue on the tarsal plate, not in the orbicularis oculi muscle anterior to the tarsal plate. Laterally, the tarsal plate becomes a fibrous band that adjoins the structural counterpart from the lower eyelid, forming the lateral canthal tendon. Medially, the tarsal plate also becomes fibrous and shelters the superior lacrimal canaliculus behind as it becomes the medial canthal tendon. 126 FIGURE 5.1 Sagittal section through orbit and globe. C, palpebral conjunctiva; LA, levator palpebral superioris aponeurosis; MM, Müller muscle; OO, orbicularis oculi muscle; OS, orbital septum; P, periosteum/periorbita; TP, tarsal plate. 127 Technique STEP 1. Protection of the Globe During surgical procedures around the orbit, the cornea should be protected with a temporary tarsorrhaphy or scleral shell after application of a bland eye ointment. STEP 2. Identification and Marking of Incision Line If an eyelid crease is not readily detectable, a curvilinear incision along the area of the supratarsal fold that tails off laterally over the lateral orbital rim is made. Remarkably, the incision in the upper eyelid follows either the lower or the upper component of a standard blepharoplasty. In case of swelling, the opposite upper eyelid crease may be mirrored. The incision should be similar in location and shape to the lateral one third to one half of the superior incision in a blepharoplasty (see Fig. 5.2). The incision, however, may be