Zygomatic Complex Fracture- ZMC

Zygomaticomaxillary Complex Fracture- all you need to know

1. ZYGOMATIC COMPLEX FRACTURE DR HIMANSHU SONI OMFS

2. CONTENTS Introduction Surgical anatomy Mechanism of injury Classification Signs & symptoms Examination- clinical & radiological Historical review of management Steps in management Surgical approaches for ZMC fractures. Complication

3. INTRODUCTION The zygoma or malar complex forms the central support of the cheek and is a strong buttress of the lateral and middle third of the facial skeleton It is for this reason that it is frequently fractured, either alone or in combination with other bony structures of the midface

4. Zygomatic or malar fracture are the terms commonly used to described fractures that involve the lateral one third of the middle face. Other names for this fracture are: Zygomaticomaxillary complex Zygomaticomaxillary compound zygomatico orbital Zygomatic complex Malar Trimalar Tripod

5. History Treatment of facial fractures recorded 25-30 century BC Smith Papyrus -first document in which treatment of several types of zygomatic fractures are described. du Verney 1751 – describe the anatomy & took advantage of the mechanical forces of the masseter and temporalis muscles on the zygoma in his approach to closed reduction techniques

6. Cont … 1906, Lothrop – antrostomy to reach fractured zygoma through highmore Antrum (inferior turbinate) 1909, Keen – intra oral approach through gingivobuccal sulcus. 1927, Gillies – temporal approach 1942 ,Adams – internal wire fixation 1951, Brown, Fryer, and McDowell – K wire. 1970 AO/ ASIF – told the role of osteosyntheis & developed miniplate for reduction of Zygoma fractures.

7. Biomechanics of maxillofacial skeleton

8. Vertical buttresses Naso -frontal Zygomatic P terygomaxillary Nasoethmoidal buttress

9. Horizontal buttress Superior Middle Inferior

10. Sicher and DeBrul were the first to depict facial anatomy in terms of structural pillars or buttresses. This concept allows consideration of an approach for reduction of midface fractures and ultimately production of a stable reconstruction. nasomaxillary buttress pterygomaxillary or posterior buttress lateral or zygomaticomaxillary buttress These buttresses help give the zygoma an intrinsic strength such that blows to the cheek usually result in fractures of the zygomatic complex at the suture lines, rarely of the zygomatic bone.

11. Zygomatic Bone Complex Anatomy Star-shape like with four processes Frontal process Temporal process Maxillary process orbital process 11 The integrity of the zygoma is critical in maintaining normal facial width and prominence of the cheek. The zygomatic bone is a major contributor to the orbit.

12. From a frontal view, the zygoma can be seen to articulate with 3 bones: medially by the maxilla, superiorly by the frontal bone, and posteriorly by the greater wing of the sphenoid bone within the orbit. From a lateral view, the temporal process of the zygoma join the zygomatic process of the temporal bone to form the zygomatic arch.

13. Articulations with facial bones

14. Z M Z m L L S L A O BUCCINATOR MASSETER Muscle attachments 14 Muscle attachments to the zygoma : Masseter Zygomaticus major Zygomaticus minor Levator labi superioris Temporal muscle & fascia Foramen : zygomatico facial foramen zygomatico temporal foramen

15. FUNCTIONS OF THE ZYGOMATIC BONE : Protect the globe of the eye Gives origin to the masseter muscle Transmit part of the masticatory forces to the cranium. Absorb forces of an impact before it reaches brain.

16. Some applied points Zygomatic bone represents a strong bone on fragile supports The traumatic force distributed through the adjacent, comparatively weaker articulating bone

17. Some applied points 2. The coronoid process of mandible moves between the arch and the infratemporal fossa . 3. The temporal fascia attached to zygomatic bone ( temporal process ) , where as the temporalis muscle via its tendon inserted in to the tip and anteriomedial surface of coronoid process of mandible . The space b/w fascia and muscle provides a route to approach the posterior surface of the zygomatic bone and the medial aspect of the arch . Utilized for elevation of bone during reduction procedure

18. Etiology RTAs ; 74.7% IPV ; 15.8 %) Forty-two cases were isolated ZMC fractures. The total number of facial fractures documented was 316, of which 222 were purely related to the ZMC . Ophthalmic injuries occurred in 30.52% of cases.

19. Other developed countries  Assaults (64.5 %) Traffic accidents ( 13.9%) F alls (13.0 %). More than one-third of all the patients experienced injury after alcohol consumption.

20. Other facts… Left Zygoma , affected most Bilateral Zygoma #, rare-4%. Male predilection with a ratio of approximately 4:1 over females. Second and third decades of life. 50 gram/cm2 is required.

21. Child Adult The Journal of Craniofacial Surgery & Volume 22, Number 4, July 2011

22. Fracture Patterns Fracture lines pass through the areas of greatest weakness of bone / between bones. Owing to the strong buttressing nature of the zygoma and the thin bone surrounding it, most injuries involving the zygoma are frequently accompanied by disruption of adjacent articulating bones.

23. Zygomatic arch fracture

24. Vertical axis Shows displacement of # in horizontal plane Blow in front of vertical axis --- outward movement of center of zygomatic arch Blow behind the vertical axis --- outward displacement of infraorbital rim and floor .

25. Horizontal axis : Shows displacement in vertical plane Impact above --- medial rotation of frontal process and slight outward rotation of buttress . Impact below horizontal axis --- lateral movement of frontal process and medial displacement of buttress in to antral cavity

26. MECHANISM OF INJURY Zygomatic fractures occur as a result of direct impact of the bone which causes fractures at one or more of its processes. Direct blows usually impact on a prominent portion like the malar eminence. Leads to a relative in bending at the point of impact and a relative out bending at weaker points.

27. Bilateral fractures are seen following higher energies Zygoma fractures are generally dislocated posteriorly and inferiorly and are frequently dislocated posteriorly , inferiorly and medially. The direction of the dislocation of the zygoma may involve rotation around several planes.

28. INCIDENCE In 90% of cases, At least one fracture line crosses the orbital floor 75% are fractures of the zygomatic complex including the orbital floor 9% are isolated fractures of the zygomatic arch Pfeifer Et Tal 1975, Blumel & Pfeifer 1977 (Rowe & Williams)

29. CLASSIFICATION Knight and North (1961) Rowe and Killey (1968) Yanagisawa ( 1973) Larsen and Thomson (1978) Rowe and Williams (1985) Poswillo’s classification Markus zing classification Manson and colleages Henderssons classification Zingg classification Ozyagzan classification

30. Knight and North Classification(1961) Group I : Undisplaced fractures Group II : Arch fractures. Group III : Unrotated body fractures Group IV : Medially rotated body fractures.

31. Group V : Laterally rotated body fractures. Group VI : Complex fractures .

32. ROWE AND KILLEY 1968 Type I : No significant displacement Type II : Fracture of the zygomatic arch Type III : Rotation around vertical axis - Inward displacement of orbital rim - Outward displacement of orbital rim Type IV : Rotation around longitudinal axis - Medial displacement of frontal process Lateral displacement of frontal process Type V : Displacement of the complex en bloc - Medial - Inferior - lateral (Rare) Type VI : Displacement of orbitoantral partition - Inferiorly - Superiorly Type VII : Displacement of orbital rim segments Type VIII : Complex comminuted fractures.

33. Zygomatic Complex Fractures (Rowe & Williams) Fractures stable after elevation a)Arch only (medially displaced) b)Rotation around the vertical axis i ) medially (medial vertical axial rotation) ii) laterally (lateral vertical axial rotation) Fractures unstable after elevation a)Arch only (inferiorly displaced) b)Rotation around horizontal axis i ) medially (medial displacement following longitudinal axial rotation) ii) laterally (lateral displacement following longitudinal axial rotation) c)Dislocations en bloc i ) inferiorly ii) medially iii) postero – laterally Communited fractures

34. ROWE’S CLASSIFICATION(1985) 1) Fractures stable after elevation Arch only (medially displaced)

35. Fractures stable after elevation Rotation around the vertical axis. Medially Laterally

36. 2) Fractures unstable after elevation . Arch only (inferiorly displaced).

37. 2 ) Fractures unstable after elevation. Rotation around the horizontal axis .

38. Fractures unstable after elevation Dislocations enbloc Inferiorly Medially Postero -laterally

39. LARSEN AND THOMSEN CLASSIFICATION Journal of Oral and Maxillofacial Surgery Volume 50, Issue 8 , August 1992, Pages 778–790 Group A : Stable fracture Group B : Unstable fracture Group C : Predicted Stable fracture Fractures of the zygomatic arch alone Minimum or no displacement. V type in fracture. Comminuted fracture

40. Yanagisawa ( 1973) GROUPS I & II – unchanged GROUP III - medial or lateral rotation around a vertical axis GROUP IV - medial or lateral rotation around a longitudinal axis GROUP V - medial or lateral displacement without rotation GROUP VI - isolated rim fracture GROUP VII -all complex fractures

41. POSWILLO’S CLASIFICATION Inward and downward displacement Inward and posterior displacement Outward displacement of the zygomatic complex Communition Fracture of the arch alone

42. MARKUS ZING Type A : Incomplete zygomatic fracture Type B : Complete monofragment zygomatic fracture Type C : Multifragment zygomatic fracture.

43. Based on pattern of segmentation , displacement and amount of energy dissipated by facial bones secondary to traumatic force: High energy Moderate energy Low energy fractures Manson and Colleagues (1990) based on the findings in the C.T. SCAN

44. Henderson's classification I Undisplaced fracture, any site II Zygomatic arch fracture only III Tripod fracture with undistracted frontozygomatic suture IV Tripod fracture with distracted frontozygomatic suture V Pure blow out fracture of the orbit VI Fracture of the orbital rim only VII Comminuted fracture or other than above

45. BASED ON ANATOMIC POINTS DIVIDES FRACTURES INTO 3 CATEGORIES: CATEGORY A Isolated # of 1 of the 3 processes of zygomatic bone. CATEGORY B: # Of all 4 processes , detaching zygomatic bone from facial skeleton . CATEGORY C: same as type b, but with fragmentation, including the body of zygoma . ZINGG CLASSIFICATION SYSTEM

46. OZYAZGAN et al Classification for arch fractures Isolated zygomatic arch fractures (type I) Dual fracture (type I – A) More than 2 fractures (type I – B) 1) V-shaped fractures (type I – B – V) 2) displaced fractures (type I – B – D) Combined zygomatic arch fractures (type II) Single fracture (type II –A ) Plural fracture ( type II – B) 1) reduced ( type II – B – R) 2) displaced ( type II – B – D) (JOMS, vol 65, 2007)

47. Classification of zygomatic arch fractures

48. J Oral Maxillofac Surg 2007 .

49. A New Proposal of Classification of Zygomatic Arch Fractures

50. Signs & Symptoms Flattening of cheek Swelling of cheek Periorbital haematoma Subconjunctival haemorrhage Ecchymosis and tenderness intra-orally over zygomatic buttess Limitation of ocular movement Diplopia Enophthalmos Lowering of pupil level

51. Epistaxis Tenderness over orbital rim and frontozygomatic suture Step deformity of infra-orbital margin Seperation at frontozygomatic suture Limitation of mandibular movement Anesthesia of cheek, temple, upper teeth and gingiva Possible gagging of back teeth on injured side.

52. DIAGNOSIS OF ZYGOMATICOMAXILLARY COMPLEX FRACTURES

53. Clinical examination First step is to assess neurological status……. Associated neurologic injury was encountered in 57 % of patients . Classification and Surgical Management of Orbital Fractures: Experience With 111 Orbital Reconstructions Manolidis , S.*; Weeks, B. H.*; Kirby, M.*; Scarlett, M.†; Hollier , L .‡ Journal of Craniofacial Surgery: November 2002 - Volume 13 - Issue 6 - pp 726-737

54. Clinical examination Inspection : performed from frontal, lateral, superior and inferior views Should be systemic and thorough Orbital rims – with index finger Lateral orbital rim – with index finger and thumb Fractures are mostly associated with step deformity and tenderness Zygoma and zygomatic arch are best palpated with two or three fingers in circular motion. Intraoral palpation Palpation

55. Peri -orbital examination Oedema Circumorbital ecchymosis Subconjunctival haemorrhage Orbital Emphysema

56. Laceration Ptosis Canalicular injury Canthal tendon displacement

57. Visual acuity Visual fields pupils diplopia ALSO SEE !!

58. Extraocular movements

59. Flattening of malar prominence

60. Unequal pupillary level

61. Trismus Abnormal Nerve sensibility present in approx. 50% to 90%

62. Radiographical evaluation 65 Nothing is more valuable to the surgeon in determining the extent of injury and the position of the fragments-both before and after operation- than a good skiagram (radiograph) HD Gillies , TP Kilner and D Stone, 1927

63. RADIOGRAPHIC EXAMINATION Postero -anterior oblique view (OM/PNS view): excellent assessment of sinuses and their walls, zygoma and its processes and rims of orbit Submentovertex view is specific for zygomatic arch fractures

64. Normal P-A oblique (waters view) Emergency Medicine Journal 2007

65. SUBMENTOVERTEX RADIOGRAPH.

66. CT Scans

67. Treatment Timing: As early as possible unless there are ophthalmic, cranial or medical complications Preiorbital edema and ecchymosis obscure the fine details of the fracture, intervention can be postponed but not more than a week Indications: Diplopia Restriction of mandibular movement Restoration of normal contour Restoration of normal skeletal protection for the eye

68. Management of the ZMC and arch fractures depends on the degree of displacement and the resultant aesthetic and functional deficits. Treatment ranges between simple observation of resolving swelling, extraocular muscle dysfunction and paraesthesia to open reduction and internal fixation of multiple fractures

69. Goals in management of zygomatic fractures : Diplopia to be corrected- pupillary levels to be leveled Eye muscles function to be restored Mandibular movements rendered free Facial contour repositioned Proper restoration of bony anatomy. Prophylactic antibiotics Anesthesia Clinical examination and forced duction test Protection of the globe Antiseptic preparation Reduction of the fracture Assessment of the reduction Determination of necessity for fixation

70. STEPS IN SURGICALLY TREATING A ZMC FRACTURE Application of fixation device Internal orbit reconstruction Assessment of ocular mobility Bone graft extraorbital osseous defects Soft tissue resuspension Postsurgical ocular examination Postsurgical images

71. HISTORICAL REVIEW Attempts to treat facial fractures were recorded in the 25-30 centuries BC. The Smith Papyrus is likely the first document in which treatment of several types of zygomatic fractures are described. In 1751, du Verney described the anatomy, type of fractures observed, and approach to reduction in two cases. He described the intra oral and external manipulation of fragments.

72. In 1906, Lothrop was the first to describe an antrostomy reaching the fractured zygoma through a Highmore antrum below the inferior turbinate. This allowed for rotation of the fractured zygoma upward and outward for a proper reduction. This transantral approach is known today as the Caldwell-Luc approach. In 1909, Keen categorized zygomatic fractures as those of the arch, the body, or the sutural disjunction. He was the first to describe an intraoral approach to the zygomatic arch via a gingivobuccal sulcus incision.

73. In 1927, Gillies was the first to create an incision made behind the hairline and over the temporal muscle to reach the malar bone. Gillies further described the use of a small, thin elevator that is slid under the depressed bone enabling the surgeon to use the leverage of the elevator to reduce the fracture. The Gillies method remains in use today to elevate the arch. Adams recognized the need for greater stabilization in more comminuted fractures and was one of the first to write of internal wire fixation.

74. However, semirigid fixation with miniplates offers the most reliable method available today for the treatment of zygomatic orbital fractures and has replaced every other method Only the increased cost and occasionally to remove the plates are the only disadvantages (JOMS, vol 56, 1998)

75. SURGICAL APPROACHES TO ZMC FRACTURES A standard series of approaches has been used extensively for approaching the fractured zmc and orbit. Existing laceration are often used for this purpose.in the absence of lacerations, properly placed incisions offer excellent access with minimal morbity and scarring.

76. GENERAL PRINCIPLES Avoid important neurovascular structures Use as long incision as necessary Place incision perpendicular to surface of non hair bearing skin Place incision in the line of minimal tension Seek other favorable sites for incision placement

77. APPROACHES Temporal approach – Gillies (1927) Buccal sulcus approach – Keen (1909), Balasubramanium (1967) Lateral coronoid approach – Quinn (1977) Eyebrow approach- Dingman & Natvig (1964) Percutaneous approach - Stroymeyer (1844) INDIRECT REDUCTION

78. Temporal approach F irst described by Gillies & coworkers in 1927 Advantages : Allows application of greater amount of controlled force to disimpact even the most difficult zygomatic fracture . For treatment of fractures which are consolidated already Quick and simple method Disadvantage: encountered temporal vessels---- hemorrhage

79. PLACEMENT OF ROWES ZYGOMATIC ELEVATOR AND ELEVATION.

80. Buccal sulcus approach Keen’s Technique (1909) Avoidance of any external scar. A small incision (approximately 1 cm) is made in the mucobuccal fold, just beneath the zygomatic buttress of the maxilla. A heavier instrument inserted behind the infratemporal surface of the zygoma , and using superior, lateral, and anterior force, the surgeon reduces the bone.

81. Technique of lateral coronoid approach Simple method for isolated arch fractures. 3 to 4 cm incision -anterior border of the ramus. To the depth of the temporal muscle insertion Instrument between the temporal muscle and the zygomatic arch - readily palpable. A flat-bladed instrument, inserted into the pocket Arch is elevated

82. Elevation From upper eyelid Approach Advantage Fracture at the orbital rim is visualized directly, and fixation of the fracture at this point can be undertaken through the same incision. Disadvantage Difficult to generate a large amount of force, especially in the superior direction. DINGMANS ZYGOMATIC ELEVATOR

83. Percutaneous Approach Most simple of all techniques as no soft tissue dissection is necessary Direct route to elevation of the depressed zygoma is through the skin surface of the face overlying the zygoma. Advantage Produces forces anteriorly , laterally, and superiorly in a very direct manner, without having to negotiate adjacent structures with the instruments. Disadvantage - Scar on the face in a very noticeable location .

84. Elevation Of The Zygoma With A Bone Hook. Poswillo`s intersecting lines. Stab incision made and hook inserted. Apply strong traction. Carrol -Girard bone screw

85. Surgical approaches to zygomaticomaxillary complex fracture Maxillary vestibular approach Supraorbital eyebrow approach Upper eyelid approach Lower eyelid approach Transconjunctival approach Coronal approach DIRECT REDUCTION

86. Maxillary Vestibular Approach The Maxillary vestibular approach is one of the most useful when performing any of a wide variety of procedures in the midface . It allows relatively safe access to the entire facial surface of the midfacial skeleton, from the zygomatic arch to the infraorbital rim to the frontal process of the maxilla Advantage the greatest advantage is the hidden intraoral scar. The approach is also relatively rapid and simple, and complications are few.

87. Surgical anatomy Infraorbital nerve Nasolabial musculature Buccal fat pad Note that the fat pad extends anteriorly to approximately the first molar. Also, posterior to the origin of the buccinator muscle on the maxilla, the buccal fat pad is just lateral to the periosteum . Important facial muscualature when performing the maxillary vestibular approach

88. Technique Subperiosteal Dissection Closure Incision through the mucosa, submucosa , facial musculature, and periosteum

89. LATERAL BROW APPROACH Access to the lateral orbital rim and the frontozygomatic suture Simple, safe and rapid approach Scar is usually hidden within the confines of the eyebrow

90. SUPRAORBITAL APPROACH A previously popular incision used to gain access to the superolateral orbital rim is the eyebrow incision.

91. ADVANTAGE: No important neurovascular structures are involved in this approach. 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, some hair loss occurs, making the scar perceptible

92. DISADVANTAGE Unfortunately, in individual who has no eyebrows extending laterally and inferiorly along the orbital margin, this approach is undesirable. Incisions made along the lateral orbital rim outside of the eyebrow are very conspicuous in such individuals, and another type of incision may be indicated. The main disadvantage of the approach is extremely limited access.

93. TECHNIQUE Incision within confines of eyebrow hair. The incision is made through skin and subcutaneous tissue to the level of the periosteum in one stroke. 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 . Closure: The incision is closed in two layers, the periosteum and the skin.

94. UPPER EYELID APPROACH The upper eyelid approach to the superolateral orbital rim is 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. Advantage: Inconspicuous scar it creates, which makes it one of the best approaches to the region.

95. TECHNIQUE Closure: The wound is closed in two layers, periosteum and skin/muscle. To facilitate retraction of the skin/muscle flap, it can be widely undermined laterally and retracted with small retractors. Because of the concavity just behind the orbital rim in this area, the periosteal elevator is oriented laterally as dissection proceeds posteriorly . Sagittal section through orbit and globe showing dissection between orbicularis oculi muscle and the levator aponeurosis below and orbital septum above The incision may be extended farther laterally if necessary. The initial incision is made through skin and muscle.

96. Lower eyelid approaches

97. Subciliary incision is made approx 2 mm below the eyelashes and can be extended laterally as necessary (top dashed line). It is made throug skin only. the incision must follow the crease as it tails off inferiorly

98. TRANSCONJUNCTIVAL APPROACH Originally described by Bourguet in 1928. Also called inferior fornix approach. 2 types: preseptal ( Tessier ) & retroseptal ( Tenzel&Miller ) approaches. Converse & colleagues added a lateral canthotomy to transconjunctival retroseptal incision for improved lateral exposure.

99. Advantage : produce excellent cosmetic results because 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 with an inconspicuous scar. Another advantage is that these techniques are rapid, and no skin or muscle dissection is necessary. Disadvantage : medial extent of the incision is limited by the lacrimal drainage system.

100. TECHNIQUE Sagital section through orbit showing preseptal and retroseptal placement of incision. Initial incision for lateral canthotomy the initial canthopexy incision to dissect in the subconjunctival plane. The dissection should be just below the tarsal plate and extend no farther medially than the lacrimal punctum . Closure of transconjunctival incision and inferior canthopexy

101. CORONAL APPROACH The coronal or bi-temporal incision is a versatile surgical approach to the upper and middle regions of the facial skeleton, including the zygomatic arch Advantage: the surgical scar is hidden within the hairline. When the incision is extended into the preauricular area, the surgical scar is inconspicuous.

102. TECHNIQUE Incision placement Incision of periosteum across the forehead from one superior temporal line to the other. The tension through periosteum should be 3 to 4 cm superior to the orbital rims Amount of exposure obtained with complete dissection of the upper and middle facial bones using the coronal approach.

103. HEMICORONAL APPROACH

104. MODIFICATION OF HEMICORONAL APPROACH The anterior arm of the incision is curved downward toward the superior wall of the orbit befor it reaches the vertex of the skull within the hairline. The ‘ backcut ’ provides excellent exposure of the entire zygomatic complex and the arch, is aesthetic and is less invasive thereby being quite acceptable by patients. Journal of Maxillofacial and Oral Surgery 2010 Volume 9, Number 3, 270-272

105. Common methods include wire osteosynthesis and rigid fixation by plates Less common methods include external pin fixation and maxillary antral support IMMOBILIZATION

106. PIN FIXATION External pin fixation Can be used for fractures that demonstrate an intact body of the zygoma but severe communition at the junction with the surrounding bones Internal pin fixation Was introduced by Fryer and results in stable entity and relatively free of complications Techniques make use of K-wire placement

107. SINUS PACKING SUPPORT Gauze or balloon can be used to provide inferior support to the zygoma Lateral wall is approached through a Caldwell-Luc ½ inch gauze dipped in antibiotic of choice is placed along the floor anteroposteriorly Antral balloon can be used by it is relatively imprecise and cannot adapt to the topography

108. Applied aspect Access to zygomatic buttress region : Modified intraoral buccal sulcus approach Access to frontozygomatic buttress : Upper eyelid approach Supra-orbital eyebrow approach Hemicoronal approach

109. Access to infraorbital buttress : Transconjunctival approach Subciliary approach Endoscopic approach ( intrasinus approach ) Access to zygomatic arch : Direct percutaneous approach Gillies temporal approach Keen’s buccal sulcus approach Lateral coronoid approach Hemicoronal approach

110. Need for fixation Indications for fixation Comminuted fracture fragments. Doubt regarding the stability Role of masseter in displacement. Albright and McFarland recommended IMF following fracture reduction helps to reduce the pull of the masseter muscle on the repositioned ZMC. Dal Santo and colleagues compared masseter muscle force post trauma and found that the muscle developed significantly less force amongst pts who sustained zmc fractures and even after 4 weeks the force was below control levels. Ellis et al reviewed series of isolated ZMC fractures treated by different approaches and fixation schemes and found no evidence of post reduction instability

111. PURPOSE OF FIXATION Infraorbital rim and buttress Lateral orbital rim Buttress of zygoma Vertical Height Facial width & orbital volume Malar Projection

112. WIRING Generally, a wire in the zygomatico - frontal suture and at the infraorbital rim is prevents inferior displacement In case of displaced fracture. Three-wire fixation of the zygoma usually provides stable fixation Inferior rim wiring Frontozygomatic suture wiring Buttress region wiring

113. WIRE FIXATION Advantages. Material availability. Minimal incision necessary. Ease of use. Disadvantages. Wires stretch. Provides one dimensional stability. Requires direct apposition of bone at fracture site. Zygoma malpositioning and malunion.

114. Holes at FZ suture area drilled into orbit. Wires inserted at FZ region infraorbital rim and zygomaticobuttress regions. TECHNIQUE

115. Holes at FZ suture area drilled into temporal fossa . Wires twisted in the temporal fossa .

116. KEY POINTS. Three point wire fixation and two point wire fixation, including the FZ region and infraorbital region or maxillary buttress are probably stable in simple fractures of the zygoma . If there are areas of comminution or a continuity defect at any of the planned fixation points then rigid fixation with bone plates is necessary.

117. INDIRECT FIXATION TRANSFACIAL WIRE TRANSNASAL WIRE ZYGOMATICOMAXILLARY WIRE ZYGOMATICOPALATAL WIRE

118. EXTERNAL FIXATION Accomplished with wires suspended from plaster head caps, head frames and by pins connected to one another with universal joints and cold cure acrylic. ADVANTAGES- Three dimensional stability. Minimal scarring. Adjustability of the reduction. DISADVANTAGES- Patient comfort is compromised. Need for specific hardware. Lack of usefulness in comminuted fractures.

119. FIXATION TECHNIQUES - PRINCIPLES Use self-threading bone screws. Use hardware that will not scatter postoperative CT scans. Place at least two screws through the plate on each side of the fracture. Avoid important anatomic structures. Use Y,L,T shaped plates where fracture line in the zmc buttress region is low. Prevents damage to the roots and nerve bundle .

120. 5. Use as thin a plate as possible in the periorbital areas. 6. Place as many bone plates in as many locations as necessary for ensuring stability. 7. If concomitant fractures of other midfacial bones exist, it will be necessary to apply fixation devices more liberally. 8. In areas of comminution or bone loss, span the gap with the bone plate.

121. BONE PLATES FOUR POINT FIXATION- COMMINUTED ZMC FRACTURES SITES OF FIXATION- F-Z SUTURE. INFRAORBITAL RIM. ZYGOMATIC ARCH. MAXILLARY BUTTRESS.

122. THREE POINT FIXATION- NON-COMMINUTED ZMC FRACTURES SITES OF FIXATION- F-Z SUTURE. INFRAORBITAL RIM. ZYGOMATIC ARCH. (OR) MAXILLARY BUTTRESS.

123. TWO POINT FIXATION- SIMPLE NON-COMMINUTED ZMC FRACTURES SITES OF FIXATION- F-Z SUTURE. INFRAORBITAL RIM. MAXILLARY BUTTRESS.

124. Order of reduction and fixation in ZMC fracture with orbital floor recontruction .

125. Placement of first plate

126. Fixation of first plate

127. Placement of second plate

128. Placement of third plate

129. Complications

130. Complications of periorbital incision – Minor - dehiscence hematoma / seroma lymphedema Vertical shortening of lower lid prevention - superior support of lower lid for several days( best achieved with frost sutures). Ectropion – associated with subciliary incision and trans conjunctival incision(mild /moderate/severe) Entropion - occurs less commonly but more distressing

131. Infraorbital nerve injury – Either direct injury to nerve due to trauma or iatrogenic Mostly these injuries are temporary( neuropraxia ) due to stretching or compression of infraorbital nerve. Markedly displaced fractures - neurotmesis can occur Patient may complain of numbness , different sensation and pain on heat /cold or light touch . ZMC fracture which are treated with rigid fixation – early recovery of neurosensory deficit .

132. Persistent Diplopia- Diplopia , commonly known as double vision, is the simultaneous perception of two images of a single object Binocular diplopia initially present with ZMC fracture should resolute within 5-7 days after fracture treatment Result of edema or hematoma of one or more extraocular muscles or their nerves Introrbital edema Ocassionally muscle entrapment If persists , it may be due to scar contracture and a dhesions either within the ocular muscles or between them and other structures.

133. Enopthalmos Most commonly caused by increased volume of orbit Difficult to correct secondarily, however improvement is possible. Surgery can be done to reduce orbital volume by – reconstructing the internal orbit - by placing a space occupying material behind the globe ( glass beads , silicon sheets , sponges , teflon beads , cartilage graft, hydroxyl apatite, metallic mesh or plate)

134. Blindness Occasionally reported after ZMC fracture Causes- direct damage to optic nerve - hemorrhage into optic sheath - intraocular edema - retrobulbar hemorrhage Maxillary sinusitis- Caused by inflammation of sinus membrane and occlusion of ostium. Usually respond to antibiotic and decongestant therapy.

135. Ankylosis of zygoma to coronoid process : - very rare - when noted usually fibrous. Causes- - improper reduction of zygoma leaving arch in close proximity to coronoid process. - untreated zygomatic fracture - post-operative infection

136. Malunion of the zygoma Signs and symptoms – Flattening of malar prominence Enopthalmos Altered pupillary level Limitation of mandibular movements Treatment - camouflaging the defect with implant or transplant - repositioning of malpositioned bone

137. CONCLUSION The treatment of zygomatic fractures has dramatically progressed over the past several decades from an entirely closed approach to the more aggressive open reduction and rigid miniplate fixation of today.