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GITAM DENTAL COLLEGE & HOSPITAL
Oral & Maxillofacial Surgery
Zygomatic complex anatomy,fracture & treatment
Dr. Satyajit Sahu
3) Key words
4) Surgical anatomy
Different approaches of treatment
6) Role of bone grafts
7) Recent advancements (endoscope)
9) Post operative care
ZYGOMATIC COMPLEX ANATOMY,
FRACTURE AND TREATMENT
Dr. Satyajit Sahu.
yr. MDS, Dept of Oral & maxillofacial surgery.
Gitam Dental College & Hospital. VIZAG
Successful repair of zmc # requires an accurate diagnosis, appropriate surgical exposure and precise
reduction to reconstitute the complex 3d anatomy.
To eliminate cosmetic, functional, ophthalmological complications and to establish appropriate
treatment modality keeping complications in mind.
KEY WORDS –Surgical anatomy, pathophysiology, surgical approaches, reduction, internal fixation,
complication, postoperative care.
SURGICAL ANATOMY – Zygoma has 4 projections, which create a quadrangular shape.--
The zygoma articulates with 4 bones. --
Zygomatic complex fracture includes disruption of the 4 articulating sutures.--
ZYGOMATIC ARCH –
It includes temporal process of zygoma and zygomatic process of the temporal bone.
- It gives support or protects the internal structures on side of the face from the direct hit.
- It protects temporalis muscle.
- It protects contents of infra temporal fossa.
- It gives esthetical fullness to the side of the face.
-it gives origin to masseter muscle
Imp-it directly releates to the stabilization of the # segment post reduction.
-displacement of releated # bones directly releates to the masseteric pull.
-it gives insertion to the temporalis fascia.
Imp –the fascia produces resistance to inferior displacement of a fractured fragment by the downward
pull of the masseter muscle.
-in surgical reduction of a #zygoma by Gillies approach,it plays an imp guideline.
Temporalis muscle –
It is an associated structure. It is the most significant muscle because it is the kinetic muscle of the
mandible. Disturbance to it, causes trismus, and if trauma occurs to it while in open mouth-pt unable to
close to it and same in otherwise.
ZYGOMATIC BONE --
-it gives support to the orbit.
-it resists (vertical stress)occlusal stress by various buttresses.
-it gives strength and stability to the mid face
-it gives the cosmetic fullness to the face.
*Point of greatest prominence(malar eminence) on the cheek arises at the intersecting between the
vertical axis and the horizontal axis.
-levator labii superioris.
*The position of the globe in releation to the horizontal axis is maintained by Luckwood’s suspensory
- This attaches medially to the posterior aspect of the lacrimal bone and laterally to the Whitnall’s
tubercle.(which is 1 cm below the zygomatico frontal suture on the medial aspect of the frontal process
of the zygoma.)
-The shape and location of the medial and lateral canthi of the eyelid are maintained by canthal
tendons .the medial canthal tendon is attached to whitnall’s tubercle.
-whenever fracture line involves whitnall’s tubercle ,it usually accompanied by an ‘’ antimongoloid
- Zygomatico tamporal -- zygomatico temporal nerve
- Zygomaticofrontal -- zygomatico frontal nerve
Associated foramen –
- Infra orbital foramen --Infraorbital nerve and vessels.
-the forward projection of zygoma causes it to be injured frequently.
-it is the 2nd
most common #,behind nasal fractures .
-male predilection – 4:1 .
-most often in the 2nd
- 80% -- caused by motor vehicle accident.
- 20% --interpersonal violence and falls.
* The zygoma may be separated from its 4 atriculations.this is called a zygomatic complex fracture.the
terms trimalar or tripod fracture are therefore incorrect or inaccurate.these terms reflect an inability to
easily identify the zygomatico sphenoid portion of the injury before the advent of the CT.For this reason
the newer accurate term for this kind of fracture is tetrapod fracture.
Kinetic energy present in an object = fnction of the mass x square of its velocity.
(The dispersion of this kinetic energy during acceleration produces the force that results in injury.)
Impact – high impact or low impact.(depending on greater or lesser than 50 times the force of gravity.)
Two classifications accepted widely.
1)By Zingg’s et al –
Type –A – incomplete low energy fracture with fracture of only 1 zygomatic pillar.
a) Isolated zygomatic arch #
b) Isolated lateral orbital wall #
c) Isolated infra orbital rim #
Type – B – complete monofragment # with #and displacement along all 4 articulations.
Type –C -- multifragment fractures included fragmentation of the zygomatic body.
2) By Manson and colleagues (1990)
Based on pattern of segmentation and displacement
- Low energy # -- incomplete fractures of 1 or more articulations may be present ,with or without
- Intermediate energy # --complete # of all articulations with mild to moderate
displacement.comminuation may be present.
- High energy # -- comminuation in the lateral orbit and lateral displacement with segmentation
of the zygomatic arch.
Clinical diagnosis –
1)Eye – a) Vitreous hemorrhage
Optic nerve damage
Incidence is ---5% of zmc # (suspects trauma to the eye)
b)Subconjunctival echymosis – 50%-70% of zmc #.
c)Displacement of palpebral fissure
d)Unequal puppillary level
e) Diplopia –monocular
-binocular (10%-40%of zmc #)
2) Zygoma –
a) Malar depression –( 70%-86% of zmc #)
b) Step off deformity at infraorbital rim.
c)Pain with # segment.
3) Oral Cavity –
a)Ecymosis in the maxillary buccal sulcus.
b)Irregularities in the normally smooth contour of the zygomatic buttresses of the maxilla.
of zmc # cases)
Either due to impingement of the translating coronoid process or a muscle spasm 2ndry
impingement of the displaced frgments.
4) Nose/ Sinuses –
a) Unilateral Epistaxis – 30%-50% of zmc #.
b)Crepitance in the facial soft tissues .
5) Neuralgic Symptoms & Signs –
a)Pain – unless ther is mobility.
b)Infraorbital Paresthesia- 50%-90% of zmc #.
Controversies- Taicher et, al compared method of fracture repair to residual inffraorbital nerve
disturbance at 1 yr and found that the best result was with mini plate osteosynthesis aat only 25%.
RADIOLOGICAL EXAMINATION --
1)Plain films –
a)Posteroanterior oblique view
b)Submental vertex view
2)CT Scan –
It is advisable because at least 50% of these pts will have concomitant injury.
a) 5mm axial slices from the hard palate through the posterior fossa,followed by 10mm axial slices
to the skull vertex.(for rapid assessment in craniofacial trauma).
b) A CT of the facial bones can then be performed with 3mm sections and includes a series of
coronal cuts if the pt can tolerate the neck extension.
1-1.5mm axial images into coronal and saggital cuts with acceptable resolution to avoid neck
flexion and extension.
According to Canvington,the need for orbital floor repair has declined from 90% to 30%,which he
attributes to the improved imaging afforded by CT.
*(1) Oblique sagital view as an adjunct to CT (coronal) for the evaluation of orbital #.
- Location and size of the #in an antero posterior dimension and volume displaced from the orbit
into the maxillary sinus and evidence of inferior rectus entrapment were improved.
- (-ve) it doesn’t help in estimating size and location of the # in a medial –lateral dimension.
*(2)Ultrasound versus computed tomography ,in the imaging of orbital floor#.
- Ultrasound with a curved alternative method in the investigation of orbital floor fractures.
3)Forced Duction Test (for binocular diplopia) –
FDT done by grasping the inferior rectus through the conjunctiva,and when positive usually
indicates an inability to rotate the globe superiorly because of orbital floor entrapment .
Latest tech/alternate tech –
-use of Succinyl choline -
Succinyl choline produces a sustained contraction of the extra ocular muscles that interferes
with an accurate interpretation of the FDT for upto 20 mins.
(used prior to strabismus surgery-while doing study)
- (-ve)Pancuronium,a non ddepolarizing muscle relaxant alter the FDT.
Management of zygomatic complex and zygomatic arch# depends on the degree of displacement and
resultant esthetic and functional deficits.
Indications for no treatment-
- Nondisplaced and minimally displaced # (low energy#).
- Elderly patient.
Indications for treatment –
Significant cosmetic and functional deformity
-orbital apex syndrome.
Extra occular muscle dysfunction.
-strangulations & edema.
-acute orbital dystopia (immediate surgical intervention)
Significant orbital floor disruption.
Displaced or comminuated # (result in cosmetic deformity and surgical repair).
DIFFERENT APPROACHES FOR REDUCTION
1)Temporal Approach ( Gillies et al,1927)
Indication -- a) isolated zygoma #
b) isolated zygomatic arch #
a) good stability after reduction
b) less chances of infection
c) helpful in Endoscopic assisted surgeries.
*(3)On the basis of complex projection ,height,lateral position the ORIF is preferable compared
*(4)controversies on masseteric muscle’s role in post reduction of zygoma without ORIF.
-certain studies says,post reduction displacement occurs in GA due to masseteric pull.
-some studies says, masseteric pull is not significant to cause destabilization of fractured
Skin incision made 2.5 cm superior and 2.5cm anterior to the helix and carried down to the
The fascia is incised and a periosteal elevator is advanced inferiorly until the medial surface of
the arch and temporal surface of the zygomatic body are identified.
The Rowe’s zygomatic elevator is inserted and used to perform the reduction.
2) Buccal Sulcus approach –
Indications – In zygoma fracture and zygomatic arch #.
Advantages –Less force is required.
Disadvantage – The procedure as it approaches through oral cavity.
A one cm incision is made in the gingivobuccal sulcus just beneath the zygomatic buttresses and a Freer
elevator is inserted to dissect the soft tissues in a supra periosteal plane.
A heavier instrument is then inserted and by applying superior ,lateral force the bone can be reduced.
3) Eyebrow Approach –
In orbital #
Zygomatic arch #
Disadvantages – difficult to generate large amount of force (superiorly).
Incision given approximately 1cm above the outer canthus of the eye,and carried down to the
A heavy instrument is inserted posterior to the zygoma .
Instrument used to lift the zygoma anteriorly ,laterally and superiorly.
4) Percutaneous Approach –
Indication – Suitable for zygomatic fracture and zygomatic arch #.
Advantage – High stability after reduction.
Disadvantage – Scarring .
Technique (Bone hook) –
The point of the hook is inserted through the soft tissues of the malar area at a point just
inferior and posterior to the prominence of the zygoma,so that it engages the infra temporal
Other instruments – Towel clip,Bone screw.
5) Intra sinus Approach –
Limitation -- Applicable only where a rotation around the vertical axis has taken place in a median
direction causing a depression of the zygomatic bone into the antral cavity.
Advantages – No scarring.
Perforation chances are there with the wall of the sinus.
Perforation of roof can lead the instrument into the orbit.
Technique – A gingivobuccal sulcus incision followed by a Caldwell-Luc opening if the anterior sinus wall
is intact,an elevator is placed behind the zygoma for reduction.
6) Transconjunctival Approach --
(Sagital section through orbit showing preseptal and retroseptal placement of incision.)
Orbital rim #
Orbital floor #
Two different methods of this approach –
-proponents of the retroseptal method claim that leaving an intact lower eyelid reduces the rate of
ectropion while preseptal advocates favour avoiding the orbital fat.
-both methods are technically demanding and take more time than the blepharoplasty incisions,but
leave no external scar.
Appling et al recently compared transconjunctival with subcilliary approaches and
demonstrated a significantly lower rate of ectropion and less scleral show,while also advocating
the use of lateral cantholysis and canthotomy.
Zingg’s study used the transconjunctival approach exclusively and had complication rates under
one percent (1%).additionaly he reports no instances in which this approach required a lateral
canthotomy for additional exposure
*(5) C- Shaped extended transconjunctival approach –
-it is possible to have one field of vision to ostotomize the frontozygomatic suture,the lateral
orbital rim,lateral maxillary buttress,and zygomatic arch.
-less operating time ,post surgical scars are shorter than bicoronal approach.
7)Supraorbital Approach --
Palpate the fracture site.
Do not shave the eyebrow
Incise down to periosteum in one stroke parallel to the hair shafts.
Incise and elevate periosteum.
Reduce the # segment.
SURGICAL APPROACH --
To zygomaticomaxillary buttress –
After throat pack is given and local anaesthesia infiltrated.
Incision is made in the maxillary vestibule 3 -5 mm above the mucogingival junction.
The incision extends from the canine area to the 1st
The use of electro cautry may reduce bleeding.
The periosteal incision is made,and a mucoperiosteal flap is elevated to expose the infra nerve,
piriform rim and zygomaticomaxillary buttress.
*By additional support, dissection infraorbital rim could be visualized.
Controversies – controversy exists regarding the best location for internal fixation and the number and
type of plates required.
- Multiple studies have tried to characterize the forces placed on the zygomatic complex and the
amount of fixation required to achive stability.
- These forces include -- a)the masseter muscle
b)the temporalis muscle
c)the temporalis fascia.
d)the soft tissue contracture.
Which cause rotational movement in multiple axes around the zygomatic buttress.
- Internal fixation must provide enough strength to resist these forces.
For low or middle energy # --
Stable fixation can be achieved at one or more of the anterior buttress.
The location of fixation and number of sites of fixation depend upon the fracture pattern
,location,vector of displacement and degree of instability.
-occasionaly one point fixation may be adequate.
-more commonly 2 or 3 point stabilization is required.
For High – Energy # --
point of fixation is required.
The zygomatic arch is typically comminuated and laterally displaced.
ORIF is required to restore proper facial width and projection.
Surgical App. To The Zygomaticofrontal Butres --
Accessand exposure for open reduction of the zygomaticofrontal buttress can be achived thrugh
a supratarsal fold lateral eyebrow incision.
If present ,a preexisting laceration may be used for exposure of this region.
The incision is pla
ced in skinfold parallal to the superior palpebral sulcus above tarsal plate.it is placed
approximately 10-14mm above the margin of the upper eyelid .
The dissection is continued ,superficial to the orbital septum and over the lateral orbital rim.
A vertical periosteal incision is msde, and subperiosteal dissection will expose the fracture.
INTERNAL FIXATION –
Percutaneus wire fixation
Microplates with minimal complications
Internal Fixation of Zygomaticomaxilary Butress –
It is the ideal location for internal fixation for middle and high energy #.
Anatomic reduction of this # assists in restoring malar projection,but is difficult if the buttress is
The overlying soft tissue is thick, and plate palpability is not concern.
Therefore, this # should be stabilized with 1.5-2.0 plates.
Internal Fixation of Zygomaticofrontal Butress –
This buttress contain excellent bone for fixation and can accommodate a 2.0 plate.
The reduction and fixation of this # will reestablish the vertical height of the zygomatic complex.
Because of its narrow interface ,theis buttress may not be as helpful in evaluating reduction in
The thickness of the soft tissue overlying this region is variable .in some instances it may be
palpable.if stable fixation can be achived at other sites ,a smaller plate may be used.
Internal Fixation of Infraorbital rim –
The # should be mobilized anteriorly and stabilized.Typically a 1.0 or 1.5 microplate is used to
stabilize the infraorbital rim.
Internal Fixation of Zygomatic Arch –
It is required in high energy #,that demonstrate comminuation and lateral displacement.
Restoration of this sagital buttress assists in restoring facial projection and facial width.
Arch should be reduced first ,and the straight (not curved) shape of the arch should be
This # typically requires a large plate to resist deformational forces.
Sequence of Internaal Fixation –
A systematic approach is helpful to ensure accurate restoration of facial height, width and
For middle-energy injury --
(with exposure of all three anterior buttresses)
1) The zygomaticofrontal buttress may be stabilized temporally with an intraosseous wire.
2) Fixation of zygomaticofrontal #. & Infraorbital rim.
3) Resume the temporary wire and fix the zygomaticofrontal buttress with plate.
4) The orbital floor is reconstructed after the zygoma has been restored to its correct 3-D position.
In High-Energy # --
The zygomatic arch should be reconstructed first.
ROLE OF BONE GRAFTS –
Early bone grafting is indicated for severe injuries which there is loss of bone or extensive
Comminuation of the orbital floor and zygomatic buttress is common in high energy injuries.
These zygomatic complex fractures are often associated with other severe midface fractures
that require treatment.
Grafts may help to prevent soft tissue contraction.
*(6) Sandwich Zygomatic technique /osteotomy --
The classical approach to lateral midface hypoplasia is reconstruction with onlays.dislocation
and asymmetry,early and late infection and extrusion are possible complications with alloplastic
Irregular contours,unpredictable resorption and asymmetry are problems that can arise with
autogenous ,homogenous and heterogenous onlay grafts.
ADVANCEMENTS WITH ENDOSCOPY –
Endoscopic Approach –*(7)
With 4mm,30 degree,surgical endoscope.
Incisions –upper buccal sulcus (preauricular).
For the treatment of -- Malar arch.
Necrosis and complete resorption of the replanted arch.
If the # could be treated with small incisions like lateral brow,lower eyelid and buccal sulcus,
there it is not advisable.
Fixation of plate is more difficult.
Endoscope Assisted Diagnosis/Treatment –
Endosocope can be used to evaluate orbitl floor injury.
-4mm osteotome is used to open Sinusotomty and antrostomy.(Caldwell Sinusotomy)
-Kerssion can be used to open sinusotomy and antrostomy.(Caldwell sinusotomy).
* gentle pressure on globe can exaggerate any significant problems or prolapsed.(pulse test).
*Once surgeon can identify smaller,inconsequential orbitalfloor defects and avoid a formal orbital
PRE OPERATIVE/INTRA OPERATIVE/POST OPERATIVE OPTHALMIC EXAMINATIONS --
Pre Operative –
Palpation & Observation –Eyelid/canthal/eye position/eye movement.
Slit lamp lamp examination
Patency of the lacrimal system.
Intra Operative –
Involvement of optic nerve.
Enopthalmos (sudden change of intra ocular pressusr)
-determined by –a)digital palpation
Eyelid ptosis and extraoccular muscle imbalance.
Post Operative –
Examinations of the functions of the eye.
Patient with sighted eyes –check for visual acuity.
Loss of light perception.
Malpossition of lower eyelid –Ectropion /Intropion.
Avoid- suspend lower eyelid with a lateral frost suture by passing 5-0 nylon suture through the
skin of the upper eyelid.
1)Infraorbital paresthesia –
Incidence of sensory aiterations of the infraorbital nerve following zygomatic trauma ranges
Studies by Vriens and colleagues and Taicher and colleagues have found improved recovery of
infraorbital sensation following open reduction and internal fixation at ZFScompared with
reduction without fixation.
Presumably,anatomic reduction of the function may minimize the compression of the nerve and
allow for recovery.
Presumably,anatomic reduction of the # may minimize the compression of the nerve and allow
2)Malunion & Asymmetry –
Inadequate reduction or stabilization of zygomatic fractures may result in malunion or
Poor malar projection -- Result of uncorrected inferior and posterior rotation of the zygoma.
Increased facial width in addition to decreased malar projection – Results from inadequate
reduction of zygomatic arch as part of a high energy orbitozygomatic injury.
Malunion—That is recognized upto 6 weeks after injury may be corrected,using routine
zygomatic reduction technique.
Correction of mild late deformities includes autogenously onlay grafts or placements of
alloplastic implants such as porous polyethylene.
Severe late post traumatic deformities may require zygomatic osteotomy and repositioning.
Cranial bone grafting may also be required. Scaring and contraction of the periorbital soft tissue
may also occur.
Lid Retraction – Ectropion, entropion and canthal repositioning may need tobe corrected in
addition to osseous reconstruction.
This is the most troubling complication.
This is due to increase in the orbital volume.
Grant and colleagues described this clinical problem eloquently by comparing the shape of the
orbit to that of a cone.
The orbital rim position determines the orbital length is the height of the cone.
Clinically, poor alignment of the orbital rim may significantly increase the orbital volume and
result in enopthalmos.
Orbital floor blow out # also results in enopthalmos.
Raskin & colleagues demonstrated that, a 13% increase in orbital volume, at 4 weeks ,results
in significant enopthalmos(less than 2 mm).
In 2002, Ploder and colleagues reported that a mean #area of 4.08cm or a mean displaced
tissue volume of 1.89ml was associated with less than 2mm of enopthalmos.
In general -- 1cm of displaced tissue=1mm of enopthalmos .
*Late repair ,technically challenging.
Incidence varies from 17% -83% and depends on the time of presentation following the injury
and the pattern and severity of the injury.
*Nondisplaced zygomatic complex #s and isolated ZAs had the lowest incidence of diplopia.
While ,pure blow out #s had the highest incidence.
Diplopia realeated to edema,hematoma or neurogenic causes may resolve without intervention.
Diplopia resulting from entrapment requires exploration and reduction of herniated orbital
5)Traumatic Hyphema –
Bleeding into the anterior chamber of the eye. (the area between the clear cornea and colored
Rebleeding after treatment occurs in 5%-30% cases.
Management of Hyphema –
-elevation of head of the bed.
-patching of the injured eye.
-topical cycloplegics ,corticosteroids & beta-blockers.
-systemic antifibrinolytics,carbonic anhydrase inhibitors and osmotic agents may also be
6)Traumatic Neuropathy –
May manifest as conditions ranging from mild deficit to complete visual loss.
Treatment may include systemic steroids or surgery with orbital or optic nerve decompression.
An ophthalmologic consultation is mandatory.
7)Superior Orbital Fissure Syndrome –
Common complication following facial trauma.
Include - a) ptosis
c) forehead anaesthesia
d) fixed dilated pupil
e)proptosis (may be)
a)reduction of the fractures
c) orbital apex exploration.
d)aspiration of retro bulbar hematoma.
8)Retro bulbar hemorrhage –
It is rare but severe complication.
It is either due to initial injury or the operative correction.
Disruption of the retinal circulation may lead to irreversible ischemia and permanent blindness.
*Ord reported a 0.03% incidence of postoperative hemorrhage with visual loss.
-Ophthalmologist condition is required.(Decompression with lateral canthotomy and cantholysis
should not be delayed)
Patient’s with zygomatic fractures commonly present acutely with a complaint of trismus.
Most likely due to impingement of the zygomatic body on the coronoid process of mandible.
May be due to 2ndry
to fibrous or fibro-osseous ankylosis of the coronoid to the zygomatic arch.
Diagnosis – By CT scan.
a) Coronoidectomy- is the most common treatment.
b) If the zygoma improperly reduced –
-zygomatic osteotomy,and repositioning may be necessary to restore the
unrestricted motions of the mandible.
POST OPERATIVE CARE –
Dressing should not be placed over an operated eye.
Patient’s sighted eyes should be checked for visual acuity.(in the recovery room)
In the event of loss light perception, the pt should be returned immediately to the operating
room.(for removal of same of the bone grafts).
Passive drains are placed in temporal fossa after a coronal dissection. and are removal same
day.(small drains can be placed in orbital cavity to facilitate egress of blood ).
Antibiotics are given prophylactically.(steroids are not usually advised.
The suspensory suture given to suspend lower eyelid is removed 4-6 days.
Patient with coronal incision may shower and gently wash their hair on the 2nd
When orbital floor bone grafts have been placed, nose blowing should be avoided for the 1st
To treat zmc # and to get satisfactory cosmetic, functional and ophthalmological results with avoiding
complications by a single surgical approach is difficult, so it should be treated with a complex treatment
approach, depending on the # pattern. Various diagnostic advancements are helpful like ultra sound
approach to orbital deformities, use of succinyl choline to check binocular diplopia .But things need to
be developed more for the betterment of treatment without having any complication.
1) JOMFS, 62:456-459.2004.
2) JOMFS, 62:150-154.2004.
3) ANNALS OF PLASTIC SURGERY, 49(5):452-459.NOV-2002.
4) PLASTIC & RECONSTUCTIVE SURGERY, 115(7):1848-1854.JUNE-2005.
5) JCFS, 2001, NOV, 12(6), 603-607.
6) JCMFS, VOL-23, ISSUE-1, FAB-95, PAGE:12-19.
7) JOMFS, 31:485-488.2002.
8) MC CARTHY (PLASTIC SURGERY).