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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_4430_Библиотеки_им_академика_М_И_Перельмана
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Skin
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incision
Operative technique: aesthetic temporal augmentation
Temporalis m.
incision
Pocket
A
Fig. 6.2 Surgical incisions to access implant material beneath temporalis muscle. (A) Staggered scalp incisions and temporalis muscle
incisions to avoid suture lines overlying implant. (B) Exposure of space between temporal muscle and temporal fossa.
B
Formation of submuscular pocket
After reaching the temporal bone, a space between the temporalis muscle
and the underlying temporal bone is created (Fig. 6.2B). The dissection is
done directly on the temporal bone using the coagulation mode of the electrocautery device. The dimensions of the pocket will define the extent of augmentation. Transversely, the area of undermining will extend from the lateral
orbital rim anteriorly to just behind the hairline posteriorly. Vertically, the
dissection extends from the temporal crest to just above the zygomatic arch.
Extending the dissection beneath the zygomatic arch can result in impingement of the temporal implant on the condyle or coronoid process of the
mandible.
Shaping the implant
PMMA is prepared by mixing the powdered polymer with the liquid polymer.
After the mixture has achieved a putty-like consistency, it is placed in the submuscular pocket (Fig. 6.3). Before the PMMA hardens, it is molded to its desired
shape by manipulating the overlying soft tissues so that they project to the same
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Chapter 6 Temporal augmentation
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level as the lateral orbital rim. Any areas of overcorr ection (not uncommon laterally after molding the material to be flush with the lateral orbital rim) are
revised with a contouring burr. The muscle and the temporal fascia are reapproximated and the scalp incision is closed in layers after a satisfactory temporal contour has been achieved.
Clinical example
A 35-year-old man presented with asymmetry and imbalance of his facial contour. He was displeased with the bitemporal hollowing, which he felt was exaggerating the excessive width of his preauricular contour. In two procedures, he
underwent augmentation of the posterior/inferior mandible, augmentation of
the infraorbital rim, superficial parotidectomy, facelift, and temporal augmentation using PMMA via the submuscular approach (Fig. 6.4).
Fig. 6.3 Diagram in the axial plane shows PMMA in
space of temporal fossa.
PEARL
It is better to underaugment the
temporal contour – since any
implant undercorrection will be an
improvement, while any contour
excess is distracting.
Superficial temporal fascia
Temporalis m.
Orbital rim
Fig. 6.4 Clinical example of a patient who underwent temporal augmentation and multiple facial-balancing procedures. The
patient felt that his temporal hollowing exaggerated the excessive
width of his midface contour. In two separate procedures he underwent augmentation of the posterior mandible, augmentation of the
infraorbital rim, supercial parotidectomy, and facelift. Temporal
augmentation using methacrylate was placed under the temporal
muscle. (A) Preoperative appearance. (B) Postoperative appearance
at 2 years.
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Temporal fossa
A B
Methyl methacrylate
Operative technique: postsurgical temporal muscle violation
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OPERATIVE TECHNIQUE: POSTSURGICAL TEMPORAL
MUSCLE VIOLATION
Access
Surgical scars from the previous procedure are utilized to access the temporal
depression. A scalp flap is raised extending to the lateral orbital rim. The level
of dissection is determined by the clinical situation but the path of the frontal
branch of the facial nerve is always protected.
Temporalis muscle reattachment
Postsurgical detraction of the temporalis muscle from the temporal crest results
in two contour deformities: a depression at the superior aspect of the temporal fossa (between the temporal crest and the retracted superior border of the
temporalis muscle), and a bulge just above the zygomatic arch as a result of the
descent of the temporalis muscle belly. Mobilization of the temporalis muscle
and its reattachment at the temporal crest eliminates the inferior bulge, but only
mildly improves the more superior temporal depression.
Implant placement and immobilization
Prior to implant placement, two titanium screws (8 to 10 mm in length) are
placed into the lateral aspect of the lateral orbital rim, such that the screw head
and a portion of the screw shaft protrude from the rim surface (Fig. 6.5). These
screws will become embedded in the PMMA and serve as anchors to prevent
implant movement. The PMMA is prepared and allowed to cure until it is puttylike in consistency. It is then placed over any contour deficiencies to abut the
lateral orbital rim (Fig. 6.6). The scalp flap is placed over the reconstructed area
and molding of the PMMA is performed over the soft tissues. This maneuver
Incision follows old
bicoronal scar
Anchor screws placed in
dense temporal bone at
lateral orbital wall
Fig. 6.5 Diagrammatic representation of titanium screws placed in the lateral orbital rim to function as
anchors for the temporal implant.
Temporal crest
Attenuated temporalis m.
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Chapter 6 Temporal augmentation
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Fig. 6.6 Diagrammatic representations of PMMA
implant overlying temporalis muscle and attached
to titanium screw “anchors.” (A) Coronal view. (B)
Surface view.
Superficial temporal fascia
Anchor screw
Attenuated temporal m.
A
Methyl methacrylate molded
over temporalis m. and
smoothed to temporal crest
Anchor screws
B
Methyl methacrylate
allows all the deficiencies in the temporal area (bone, muscle, and scalp) to be
addressed and corrected during implant contouring. Areas of overcorrection
are revised with a contouring burr. A suction drain is placed, which exits from a
separate stab-wound incision. The scalp incision is closed in layers.
Clinical example
A 36-year-old female presented with temporal hollowing after craniotomy to
repair a cerebral aneurysm. The temporal hollowing was corrected, filling the
depression with PMMA over the temporalis muscle (Fig. 6.7).
PERSONAL EXPERIENCE
Temporal augmentation with PMMA is an effective means of restoring contour of
the temporal area. PMMA, which has been used for decades to reconstruct full-
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thickness cranial vault defects, is biocompatible and easily moldable. It provides
A B
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References
Fig. 6.7 This patient developed temporal hollowing after intracranial aneurysm surgery. The hollowing was corrected by placing
methacrylate over the temporalis muscle. (A) Preoperative appearance. (B) Postoperative appearance.
Fig. 6.8 Clinical photograph demonstrating exaggeration of
temporal contour after temporal augmentation with an overly large
silicone implant placed over the temporalis muscle. Note also the
poor transition between the augmented temporal area and the
native forehead.
a predictable and permanent result. When it is placed beneath the temporalis
muscle, the risk of damage to the frontal branch of the facial nerve is minimized.
Similar to that described by Ousterhout,9 the senior author’s experience has
shown that it is better to undercorrect than to overcorrect temporal contour; almost
any small amount of implant material placed beneath the temporalis muscle results
in contour improvement. Augmentation beyond the normal limits of the temporal
projection results in an easily recognizable abnormal contour (Fig. 6.8). Ousterhout
also recommended augmenting each side of the temporal area at a time. Simultaneous augmentation of areas on opposite sides of the head with a semi-liquid, rapidly
curing material is technically challenging. It predisposes to contour imperfections
resulting from gravitational and head-positioning effects on the curing material.
REFERENCES
1. Whitaker LA. Temporal and malar-zygomatic reduction and augmentation. Clin Plast Surg
1991;18(1):55–64.
2. Lambros V. A technique for filling the temples with highly diluted hyaluronic acid: the
“dilution solution”. Aesthet Surg J 2011;31(1):89–94.
3. Mojallal A, Shipkov C, Braye F, Breton P, Foyatier JL. Influence of the recipient site on the
outcomes of fat grafting in facial reconstructive surgery. Plast Reconstr Surg 2009;124(2):471–83.
4. Hu J, Chen W, Wu Y, et al. Middle cerebral artery occlusion following autologous bitemporal
fat injection. Neurol India 2011;59(3):474–5.
5. Jiang X, Liu DL, Chen B. Middle temporal vein: a fatal hazard in injection cosmetic surgery for
temple augmentation. JAMA Facial Plast Surg 2014;16(3):227–9.
6. Lu L, Xu X, Wang Z, Ye F, Fan X. Retinal and choroidal vascular occlusion after fat injection into
the temple area. Circulation 2013;128(16):1797–8.
7. Huang RL, Xie Y, Wang W, et al. Anatomical study of temporal fat compartments and its
clinical application for temporal fat grafting. Aesthet Surg J 2017;37(8):855–62.
8. Gordon CR, Yaremchuk MJ. Temporal augmentation with methyl methacrylate. Aesthet Surg J
2011;31(7):827–33.
9. Ousterhout DK. Aesthetic contouring of the craniofacial skeleton. 1st ed. Boston: Little: Brown; 1991.
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Chapter 7
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Internal orbit
The size and shape of the internal orbit determines orbital volume and the position of the eye. An increase in orbital volume results in enophthalmos – the
recession of the ocular globe within the bony orbit. The principal mechanism in
its development is the displacement of a relatively constant volume of orbital
soft tissue into an enlarged bony orbit. Posttraumatic fat atrophy and scar contracture are real, but less important, factors in causing a mismatch of soft tissue
and orbital volume.
on the globe, tending to deepen the superior tarsal fold and cause a lowering or
pseudoptosis of the upper lid (Fig. 7.1). Two to three millimeters of enophthalmos is clinically detectable, and more than 5 mm is disfiguring.
Enophthalmos may result from fractures involving only the orbital floor or
medial orbital wall. These are termed “pure blowout” fractures. More often,
enophthalmos is part of an orbital deformity whereby not only the internal orbit
is disrupted, but also the adjacent facial skeleton. The internal orbit disruption
is referred to as an “impure blowout” fracture in these situations.
Because posttraumatic enophthalmos is primarily due to damage of the internal orbit, the treatment strategy for restoring eye position is anatomic skeletal
reconstruction. This is best accomplished by defining the location and extent of
injury preoperatively with computed tomographic (CT) scans, widely exposing the injured area, retrieving displaced orbital soft tissues, and replacing the
invariably comminuted fractured skeleton.
1–3
Recession of the globe changes the drape of the upper lid
1–3
A
ORBITAL ANATOMY
The internal orbit may be conceptualized as a modified pyramid with an
apex, a base, and four walls. The optic foramen, which transmits the optic
nerve and the ophthalmic artery, forms the apex of the pyramid. It is located
at the farthest superior medial portion of the internal orbit. The base of the
pyramid is formed by the orbital rims. The roof, floor, medial wall, and lateral
wall constitute the pyramid’s walls. While the entire lateral wall consists of
thick bone created by the articulation of the greater wing of the sphenoid and
the orbital process of the zygoma, the floor, medial wall, and roof vary in their
thickness. They can be divided into concentric thirds based on bone thickness.
The anterior third of the internal orbit consists of increasingly thicker bone as
it merges with the orbital rim. The posterior third also consists of thick bone
with relatively flat walls. The middle third consists of thin bone and allows
this portion of the orbit to act as a crush zone, thereby protecting the optic
nerve and globe by absorbing impact forces. The floor medial to the infraorbital canal and the inferior portion of the medial wall is typically involved
in the “blowout” fracture. This area has a convex shape that produces a
B
Fig. 7.1 A 32-year-old woman with
posttraumatic enophthalmos. (A) Frontal
view. (B) Worm’s eye view. Note inward
displacement of the globe, deepening of the
supratarsal sulcus and pseudoptosis of the
upper lid.
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Chapter 7 Internal orbit
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constriction behind the globe (Fig. 7.2). Loss of this convexity transforms the
internal orbit shape from pyramidal to spherical, increasing orbital volume
and tending towards enophthalmos (Fig. 7.3). Certain injuries, usually involving the lateral orbital wall or roof, may result in inward displacement of larger
fracture segments. These “blow-in” fractures decrease orbital volume, resulting in globe proptosis.
There are nine openings within each orbit. Most important are the optic
foramen, and the superior and the inferior orbital fissures. The optic foramen, located at the apex, transmits the optic nerve. The superior orbital fissure, located between the roof and the lateral wall near the apex, transmits the
oculomotor, the trochlear, the ophthalmic division of the trigeminal, and the
abducent nerves. The inferior orbital fissure separates the lateral wall from the
Fig. 7.2 Orbit with its constituent bones and communications. Note
convex shape (blue arrow) of inferomedial aspect of internal orbit.
Superior orbital ssure
Optic canal
Optic n.
Inferior orbital
ssure
Infraorbital foramen
Conjunctiva
Lateral rectus m.
Optic n.
Enophthalmos
Intraorbital fat
A
Fig. 7.3 Sagittal section of orbit. (A) Intact skeleton with globe position. (B) Disrupted orbital oor with globe displacement. Loss of convexity
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of oor increases orbital volume and tends towards enophthalmos.
Floor of orbit
Periosteum
Collapsed floor of orbit
B
Maxillary
sinus
floor. Through this fissure the orbit communicates with the temporal, infratem-
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poral, and pterygopalatine fossae. It transmits the maxillary nerve, its zygomatic branch, and the ascending branches from its sphenopalatine branch. It
also transmits the infraorbital vessels and the vein that connects the inferior
ophthalmic vein with the pterygoid venous plexus. The supraorbital foramen,
infraorbital canal, anterior and posterior ethmoidal foramina, and zygomatic
foramen transmit their respective neurovascular structures. There is also a canal
for the nasolacrimal duct.
PREOPERATIVE EVALUATION
Physical examination
The clinical diagnosis of significant internal orbital disruption is based on
globe malposition. In the uninjured state, the cornea extends approximately
16 to 17 mm anterior to the lateral orbital rim. Immediately after injury,
however, globe position may appear normal or proptotic, owing to soft
tissue swelling. Without significant edema, a difference in globe position
is most easily determined by viewing the globe from the worm’s eye. On
frontal view, a deepening of the supratarsal sulcus and a lowering of the
upper lid margin (pseudoptosis) reflects an increase in orbital volume and
subsequent recession of the globe (Fig. 7.1). When the lateral orbital rim
is intact (isolated floor or medial wall blowout fractures), the severity of
enophthalmos can be determined with a Hertel exophthalmometer, which
measures the difference between the anterior corneal surface and the lateral
orbital rim.
Operative technique
Radiologic imaging
CT imaging best determines the presence and extent of injury. Plain X-rays will
confirm the presence of fractures but will not define the injury or the status of
the soft tissues. The ideal preoperative evaluation consists of thin-slice axial,
coronal, and sagittal CT sections using both bone and soft tissue windows. By
adding together the consecutive CT slices where a defect appears, one can determine the size of a floor or wall injury. Defects greater than 25% of the orbital
floor will result in clinically measurable enophthalmos. Those involving more
than half of the floor will result in obvious enophthalmos. Diplopia may result
from eye muscle contusion or muscle entrapment. This can be differentiated on
physical exam using the forced duction test and, often, by high-resolution CT
scan.
OPERATIVE TECHNIQUE
Timing
In the acute phase, CT findings coupled with forced duction testing provide the
best guide to the need for surgery.
If surgery is thought appropriate, it should be performed soon after injury,
when dissection is more straightforward, and soft tissue scarring and contracture are less problematic. Late and secondary reconstructions are less successful
than appropriate reconstruction performed in the acute phase. When indications for acute management are unclear, exploration is performed if enophthalmos greater than 2 mm develops at any time within the first 6 weeks following
4,5
injury.
PEARL
The size of orbital oor defects can
be quantied by adding coronal and
sagittal CT scan sections.
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Chapter 7 Internal orbit
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Exposure
Proper repositioning of the globe requires exposure and anatomic reconstruction of the internal orbit. A transconjunctival retroseptal incision, often with
a lateral canthotomy extension, provides excellent exposure to approach the
orbital floor and lower medial and lateral walls. The transcaruncular approach
affords added exposure to the medial wall. Skin and skin–muscle flaps that
delaminate and relaminate the lower lid can result in lid malposition when
used in the trauma setting.6 Extensive subperiosteal dissection of the lateral
orbit will detach the lateral canthus. It should be repositioned at closure.
Mobilization and retrieval of orbital contents
A small conical space and fragile contents make surgery in the internal orbit
challenging. Using loupe magnification, the soft tissue contents of the orbit are
freed from the injured skeleton by subperiosteal dissection. Care is taken to
avoid damaging the lacrimal sac and structures in the inferior orbital fissure.
Intact bone edges are identified for orientation and provide stable constructs on
which to position grafts or implants. Once the prolapsed contents of the orbit
are retrieved, a piece of silicone sheeting is useful to maintain soft tissue retraction (Fig. 7.4). This maneuver prevents the soft tissues from falling back into
the sinus, lessens repeated handling, and improves the operative field. Once
reconstruction is complete, the silicone sheet is removed.
7
This dissection can be exceedingly difficult in extensive injuries, particularly
when surgery has been delayed and prolapsed orbital soft tissues have healed to
damaged mucosa in the maxillary or ethmoid sinuses or to the temporalis muscle in
the temporal fossa. The orbital contents must be separated from these structures and
replaced in the orbit. An inferior orbitotomy increases internal orbit access, thereby
simplifying soft tissue mobilization during complex reconstructions8 (Fig. 7.5).
PEARL
Periorbital fractures should be
reduced and xed prior to internal
orbit reconstruction.
Internal orbit reconstruction
The internal orbit is reconstructed to restore its preinjury anatomy with the
anticipation that proper globe position will result.
9–12
This requires definition
of the injured area, which is best accomplished by identifying intact bone and
Fig. 7.4 A thick piece of silicone sheeting is placed beneath the retrieved
orbital contents to prevent the soft tissues from prolapsing into the
maxillary antrum when the retractor is repositioned.
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hence the limits of the defect. This process is complicated by the location and
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extent of the injury. The bony landmark that is usually most difficult to identify
is the posterior ledge of the remaining intact orbital floor. When the orbital floor
disruption extends far posterior and intact bone cannot be visualized, it can be
located by placing the end of an elevator against the posterior wall of the maxillary sinus and elevating it until it meets resistance, which indicates contact with
the intact posterior remnant of the orbital floor. This structure is usually 35 to 40
mm from the infraorbital rim (Fig. 7.6).
Operative technique
A
Fig. 7.5 Inferior orbitotomy simplies retrieval of prolapsed orbital contents from the maxillary sinus and identication of intact bony
landmarks. Anatomic replacement of the osteotomized rim segment is simplied by adapting a microplate to the rim, drilling holes,
and temporarily xing the intact rim prior to making the osteotomy. (A) Location of orbitotomy. (B) Replacement of rim segment after
reconstruction of defect.
Periosteal elevator
B
Fig. 7.6 Identication of the intact posterior ledge can be simplied
by placing an elevator against the posterior wall of the maxillary
antrum and elevating it until it meets the restriction of the intact
posterior ledge. Presence of an intact ledge must be conrmed
preoperatively by CT scans to avoid putting the optic nerve at risk.
An implant placed on this ledge provides a posterior landmark for
orientation and a stable construct for implant placement.
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