the zygomaticomaxillary complex is an important functional and aesthetic landmark of the midface , and it provides prominent cheek structure .
however , unfortunately it is very vulnerable to injury because of its intrinsically prominent convexity .
there are four bony attachments between zygoma and other facial bones : a superior attachment to the frontal bone ( frontozygomatic suture line ) , a medial attachment to the maxilla ( zygomaticomaxillary suture line ) , a lateral attachment to the temporal bone ( zygomaticotemporal suture line ) , and a deep attachment to the greater wing of the sphenoid bone ( zygomaticosphenoidal suture line ) . when blunt trauma to the zygomatic complex results in fractures of all four suture lines , it is referred to as a tetrapod fracture .
closed reduction without surgical incisions has virtually been abandoned because judgment on the adequate reduction of fracture could not been made and it often resulted in disappointing cosmetic results .
open reduction with surgical incisions has been accomplished through keen 's approach , gillies ' approach , bicoronal scalp flap approach or the more popular dingman 's approach ( 1 ) .
this procedure has advantages in that it leaves no facial scars and is simple to perform .
however , the fracture site is not directly visualized and access to the orbit is not possible , which may result in incomplete surgical reduction .
however , it necessitates a lengthy scalp incision and provides inadequate exposure to the inferior , medial aspect of orbit , and may leave a conspicuous long scalp scar . also ,
because of its extensive dissection , the temporal branch of the facial nerve may be damaged .
the dingman 's approach has become the most popular method in repairing zygomatic complex fractures .
this procedure utilizes a lateral eyebrow incision line and a second incision across the entire lower eyelid in the subciliary line .
this technique provides good exposure and direct visualization of the frontozygomatic area , inferior orbital rim and orbital floor .
but , it provides limited exposure of the lateral orbital rim because it consists of two separate facial incisions , and it leaves external cutaneous scars .
also , there is some risk of lower eyelid ectropion due to cicatrical contracture . since its first description for the removal of herniated orbital fat ,
there have been subsequent reports demonstrating the efficacy of transconjunctival approach not only for the lower eyelid blepharoplasty but also for the repair of orbital fractures ( 2 - 5 ) .
mccord and moses ( 6 ) described the addition of the lateral canthotomy incision to gain access to the lateral orbital wall and inferior orbital rim , and nunery ( 1 ) reported a lateral superior cantholysis for the repair of trimalar fractures .
since then , a few authors ( 7 - 9 ) have described the advantages of this type of incision , but there has been no report that describe the long term results of two - point fixation through the single transconjunctival incision for the treatment of zygoma fracture .
between march 2002 and january 2006 , a total of 53 patients with zygomatic complex fractures , which were not severely comminuted , were treated with this surgical method .
included were 48 men and five women , aged 15 to 88 yr ( mean age 33.2 yr ) .
twenty eight patients ( 52.8% ) had associated blow out fracture , two patients ( 3.7% ) had associated nasal bone and mandible fracture , and one patient ( 1.9% ) had associated nasal bone fracture ( table 1 ) . upon
knight and north classification , four patients ( 7.5% ) belonged to group i , twenty one patients ( 39.6% ) belonged to group ii , eight patients ( 15% ) belonged to group iv , eleven patients ( 20.7% ) belonged to group v , and nine patients ( 16.9% ) belonged to group vi .
all patients were treated with two - point fixation through a single transconjunctival approach with a lateral canthal extension . if the reduction of zygoma was not complete , an additional small gingivobuccal incision ( less than 2 cm )
was made and subperiosteal dissection was performed to expose zygomaticomaxillary buttress and posterior surface of zygoma . through the small gingivobuccal incision ,
the follow - up period ranged from 8 to 46 months ( average 24.8 months ) .
preoperative and postoperative clinical examinations were performed with special attention paid to features such as symmetry of zygoma and canthal ligaments , enophthalmos , diplopia , limited ocular function , scarring and ectropion .
follow - up radiographs ( waters ' view and zygomatic arch view ) were routinely used to evaluate the adequacy of reduction . under general endotracheal anesthesia , a lateral canthal incision , about 1.0 - 2.0 cm ,
then , the conjunctiva is incised 2 - 3 mm below the tarsus extending from the commissure to a point just lateral to the punctum , and the transconjunctival incision is connected to the lateral canthal incision ( fig .
the lower eyelid flap is pulled down by cutting the superficial lateral canthal tendon and inferior limb of deep lateral canthal tendon with fine scissors .
dissection proceeds anteriorly and inferiorly between the orbicularis oculi muscle and orbital septum until the periosteum of the inferior orbital rim is exposed . through the extended lateral canthal incision ,
the lateral aspect of the upper lid is retracted superiorly , and the periosteum of lateral orbital rim is exposed . the periosteum is incised and a subperiosteal dissection is done to expose the orbital floor , the inferior orbital rim , and the lateral orbital rim including the zygomaticofrontal suture area ( fig .
, the dingman 's elevator is placed posteriorly to the body of the zygoma along the zygomatic arch and a reduction of zygoma is done .
if the reduction of zygoma is not complete or unsatisfactory , an additional small gingivobuccal incision ( less than 2 cm ) is made and a limited subperiosteal dissection is performed to expose the zygomaticomaxillary buttress and posterior surface of zygoma .
dingman 's elevator is inserted through the small gingivobuccal incision and an accurate reduction can be accomplished . in all cases ,
complete reduction was confirmed by the accurate alignment of the lateral and inferior orbital wall .
then , the two - points ( frontozygomatic suture and inferior orbital rim ) are fixated with plates and screws ( fig .
resorbable 2.0-mm miniplates systems , macrosorb ( macropore , san diego , ca , u.s.a . ) were used in 35 patients ( 87.5% ) and titanium miniplates ( osteomed , dallas , tx , u.s.a . ) were used in 5 patients ( 12.5% ) . if there is an associated impure blow - out fracture , orbital floor reconstruction with porous polyethylene implant ( medpor ) is performed .
the periosteum is closed with a 4 - 0 absorbable suture , and the conjunctiva is closed by a 7 - 0 absorbable suture . in case of old patient with lid laxity , the canthopexy is accomplished by a 5 - 0 absorbable suture fixation in the direction of posterior - superiorly to the periosteum of lateral orbital rim to prevent the postoperative ectropion . in other cases ,
finally , the skin and subcutaneous layer at the lateral canthal incision site is closed with a 6 - 0 suture .
between march 2002 and january 2006 , a total of 53 patients with zygomatic complex fractures , which were not severely comminuted , were treated with this surgical method .
included were 48 men and five women , aged 15 to 88 yr ( mean age 33.2 yr ) .
twenty eight patients ( 52.8% ) had associated blow out fracture , two patients ( 3.7% ) had associated nasal bone and mandible fracture , and one patient ( 1.9% ) had associated nasal bone fracture ( table 1 ) . upon
knight and north classification , four patients ( 7.5% ) belonged to group i , twenty one patients ( 39.6% ) belonged to group ii , eight patients ( 15% ) belonged to group iv , eleven patients ( 20.7% ) belonged to group v , and nine patients ( 16.9% ) belonged to group vi .
all patients were treated with two - point fixation through a single transconjunctival approach with a lateral canthal extension . if the reduction of zygoma was not complete , an additional small gingivobuccal incision ( less than 2 cm )
was made and subperiosteal dissection was performed to expose zygomaticomaxillary buttress and posterior surface of zygoma . through the small gingivobuccal incision ,
the follow - up period ranged from 8 to 46 months ( average 24.8 months ) .
preoperative and postoperative clinical examinations were performed with special attention paid to features such as symmetry of zygoma and canthal ligaments , enophthalmos , diplopia , limited ocular function , scarring and ectropion .
follow - up radiographs ( waters ' view and zygomatic arch view ) were routinely used to evaluate the adequacy of reduction .
under general endotracheal anesthesia , a lateral canthal incision , about 1.0 - 2.0 cm , is made down to the periosteum of lateral orbital rim .
then , the conjunctiva is incised 2 - 3 mm below the tarsus extending from the commissure to a point just lateral to the punctum , and the transconjunctival incision is connected to the lateral canthal incision ( fig .
the lower eyelid flap is pulled down by cutting the superficial lateral canthal tendon and inferior limb of deep lateral canthal tendon with fine scissors .
dissection proceeds anteriorly and inferiorly between the orbicularis oculi muscle and orbital septum until the periosteum of the inferior orbital rim is exposed . through the extended lateral canthal incision ,
the lateral aspect of the upper lid is retracted superiorly , and the periosteum of lateral orbital rim is exposed .
the periosteum is incised and a subperiosteal dissection is done to expose the orbital floor , the inferior orbital rim , and the lateral orbital rim including the zygomaticofrontal suture area ( fig .
, the dingman 's elevator is placed posteriorly to the body of the zygoma along the zygomatic arch and a reduction of zygoma is done .
if the reduction of zygoma is not complete or unsatisfactory , an additional small gingivobuccal incision ( less than 2 cm ) is made and a limited subperiosteal dissection is performed to expose the zygomaticomaxillary buttress and posterior surface of zygoma .
dingman 's elevator is inserted through the small gingivobuccal incision and an accurate reduction can be accomplished . in all cases ,
complete reduction was confirmed by the accurate alignment of the lateral and inferior orbital wall .
then , the two - points ( frontozygomatic suture and inferior orbital rim ) are fixated with plates and screws ( fig .
resorbable 2.0-mm miniplates systems , macrosorb ( macropore , san diego , ca , u.s.a . ) were used in 35 patients ( 87.5% ) and titanium miniplates ( osteomed , dallas , tx , u.s.a . ) were used in 5 patients ( 12.5% ) . if there is an associated impure blow - out fracture , orbital floor reconstruction with porous polyethylene implant ( medpor ) is performed .
the periosteum is closed with a 4 - 0 absorbable suture , and the conjunctiva is closed by a 7 - 0 absorbable suture . in case of old patient with lid laxity , the canthopexy is accomplished by a 5 - 0 absorbable suture fixation in the direction of posterior - superiorly to the periosteum of lateral orbital rim to prevent the postoperative ectropion . in other cases ,
finally , the skin and subcutaneous layer at the lateral canthal incision site is closed with a 6 - 0 suture .
during the average 24.8 months of follow up , most patients had functionally and esthetically satisfactory results .
all patients showed satisfactory facial symmetry , no lateral canthal displacement , and no functional impairment .
none of them had persistent diplopia , enophthalmos or alteration of visual acuity . upon postoperative radiography ( skull waters view and zygomatic arch view ) ,
one patient ( 1.9% ) had persistent scleral show and was corrected three months after the repair of zygomatic complex fracture .
this case was 78 yr - old patient who had lid laxity preoperatively and showed ectropion postoperatively , which may be due to scar contracture . and
two patients ( 3.7% ) had mild hyperpigmentation at the lateral canthal incision site even after six months postoperatively .
but most of patients showed hardly visible scar in the lateral canthal area ( fig .
although subciliary incision with lateral eyebrow incision ( dingman 's approach ) is the most common approach to the zygomatic complex ( 7 , 10 ) , it can leave a visible scar and ectropion of the lower eyelid .
factors predisposing to an eyelid retraction and ectropion include hematoma , eyelid edema , adhesions of the orbital septum , scar contracture , horizontal laxity of the eyelid margin , weakening of the pretarsal muscle , and wide dissection of the anterior periosteum ( 11 ) . to decrease the complication rates of the subciliary approach , many authors have tried to treat zygoma complex fracture repair using the transconjunctival approach ( 1 , 6 - 9 ) .
they emphasized the advantage of this approach over the dingman 's approach , in terms of minimal ectropion , hidden scars , and minimal lid lymphedema . in the transconjunctival approach
, the dissection can be performed in one of two separate planes ; preseptal approach and retroseptal approach .
some authors ( 12 , 13 ) advocated that the retroseptal approach is preferred because it can be performed easily and the integrity between orbital septum and orbicularis oculi muscle is not disturbed .
however , the retroseptal approach has increased risk of injury to the inferior oblique muscle and prolapse of orbital fat into the surgical field ( 10 , 11 ) .
hence , all our patients were treated with the transconjunctival preseptal approach . in the management of the lateral canthal extension site , manson et al .
( 9 ) advocated that the canthal reattachment is not required in an acute fracture treatment but is necessary in fractures when treatment is delayed , in patients with established canthal deformities , or in patients in whom a simultaneous coronal incision is employed . according to them ,
the anterior limb of the lateral canthal tendon which is also referred to as the superficial lateral canthal tendon by other authors ( 14 ) , is continuous to the temporal fascia and galea aponeurotica and the diffuse connections of this limb facilitate proper positioning of the canthus after mobilization of the posterior limb ( deep lateral canthal tendon ) .
the current authors think that in addition to some indications mentioned above , patients of old age with lid laxity also needs lateral canthal reattachments or canthopexy .
its significance began to be considered following our case of a 78 yr - old patient who developed persistent ectropion when canthal reattachment had not been performed .
the precise physical stability of the zygoma with respect to the number and location of miniplates applied is not known , because it depends on fracture anatomy , extent , and the amount of displacement .
some laboratory studies , using human cadaver heads , have been conducted to investigate the stability of fixated zygoma . in 1989 , rinehart et al .
( 15 ) simulated noncomminuted zygoma fractures in eight human cadaver heads and the stability of fracture fixation was studied for various fixation patterns . in their study ,
double - miniplate fixation across the zygomaticofrontal and zygomaticomaxillary fracture lines is sufficient to withstand static and oscillating loading similar to physiologic masticatory forces . in 1990 , davidson et al .
( 16 ) analyzed different methods of internal fixation of simple displaced fractures of the zygoma in an attempt to define the simplest method of achieving postreduction stability . in their report , the three - point fixation ( frontozygomatic suture , inferior orbital rim , and zygomaticomaxillary buttress ) using either miniplates alone or interfragmentary wiring conferred the greatest stability .
in addition , they proposed that the two - point fixation using miniplate alone conferred a degree of stability comparable to most methods of three - point fixation regardless of the site in which the miniplates were applied .
we concur with the above assertions and think that two - point miniplate fixation at the infraorbital rim and zygomaticofrontal suture would suffice , provided the comminution of the zygoma is not severe .
although not the focus of our attention in this study , in case of severely comminuted fracture , three - point fixation through the transconjunctival incision and gingivobuccal incision is preferably performed . to fixate the fracture site and provide stability , we used four hole resorbable 2.0-mm miniplates systems , macrosorb ( macropore , san diego , ca , u.s.a . ) in most patients , and titanium miniplates ( osteomed , dalllas , tx , u.s.a . ) only when there was a segmental fracture at the infraorbital rim or when requested by the patient due to the lighter financial burden .
in addition to the inconspicuous scarring , the main advantage of this method is a direct and full visualization of the lateral and inferior orbital wall to be served as a guidance for an accurate reduction , which makes the reduction more successful .
the only drawback we experienced in our method is a little difficulty in reducing the fracture - displaced zygoma because of limited space and a slightly inadequate vector for the elevator .
usually a fractured zygoma is displaced and rotated posteriorly and medially , so an anterior - lateral pull is required .
however , the lateral canthal incision is located medially to the zygoma body and lateral pulling of the zygoma body may be a little difficult . in conclusion
, we believe that the proposed technique is very useful for the treatment of zygomatic complex fracture which is not severely comminuted , because it provides excellent exposure and postoperative stability of the zygoma with a lower incidence of complications , including visible scarring and ectropion .
 the ultimate goal in treating zygomatic complex fracture is to obtain an accurate , stable reduction while minimizing external scars and functional deformity . 
 the present authors present our experiences with a single transconjunctival incision and two - point ( inferior orbital rim and frontozygomatic suture ) fixation in 53 patients with zygomatic complex fracture which were not comminuted . 
 all patients had transconjunctival approaches with lateral canthal extensions , and six out of 53 patients also had an additional small ( about less than 2 cm ) gingivobuccal incision to achieve an accurate reduction . 
 there were 3 minor complications , and the overall esthetics and functional results were satisfactory with a long term follow - up . 
 our method has the following advantages in the reduction of zygomatic complex fracture ; it leaves only an inconspicuous lateral canthal scar . 
 in addition , it provides excellent simultaneous visualization of the inferior orbital rim and frontozygomatic suture area . 
 hence , two - point fixation through a single incision can be performed with a satisfactory stability . 
INTRODUCTION
MATERIALS AND METHODS
Patients
Surgical techniques
RESULTS
DISCUSSION