Oral Surgery Dr. Labeed Sami جامعة تكريت كلية طب االسنان املرحلة اخلامسة م.د. لبيد سامي حسن

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1 جامعة تكريت كلية طب االسنان جراحة الفم مادة املرحلة اخلامسة م.د. لبيد سامي حسن

2 5 th stage Fracture zygomatic complex As the zygomatic bone is closely associated with the maxilla, frontal and temporal bones and they are usually involved when a zygomatic bone fracture occurs, therefore these types of fractures are referred to as zygomatic complex fractures or zygomaticomaxillary complex fractures or tripod fractures. Applied Anatomy The zygomatic bone is a dense, strong structure just like a four pointed star, the convex body which is the most prominence of the cheek, with for processes ; frontal process, temporal process, orbital process forming the outer half of the inferior orbital rim and the maxillary process forming the buttress, which can be palpated in the upper buccal sulcus. The zygoma plays a major role in facial contour. The zygoma articulates with four bones the frontal, sphenoid, maxillary and temporal. 1- Frontal process,is thick and strong which articulate with frontal bone through the frontozygomaticsuture. 2- Temporal process, A slender process extends posteriorly to form along with the zygomatic process of the temporal bone, the zygomatic arch. The temporalis fascia is attached to the zygomatic bone and arch, whereas, the temporalis muscle is inserted via its tendon into the tip and anteromedial surface of the coronoid process of the mandible. The space between the fascia and the muscle provides a route to approach the posterior surface of the zygomatic bone and the medial aspect of the arch, which is utilized for elevation of the bone during reduction procedure. 3- Sphenoid process ; through which it articulate with sphenoid bone 4- Maxillary process, which articulate with maxilla through broad zygpmaticomaxillary suture Classification of the Zygomatic Complex Fracture In 1985 Rowe propose a classification and gave more clinical significance by dividing fractures into stable and unstable varieties. Group A: Stable fracture showing minimal or no displacement and requires no intervention. Group B: Unstable fracture with great displacement and disruption at the frontozygomatic suture and comminuted fractures. Requires reduction as well as fixation. 2

3 Group C: Stable fracture other types of zygomatic fractures, which require reduction, but no fixation. Fractures of the zygomatic arch alone not involving the orbit can be classified as follows: 1- Minimum or no displacement. 2- V type infracture. 3- Comminuted fracture. Signs and Symptoms 1- Flattening of the injured cheek (possibly masked by swelling). Immediately following the injury or after the acute phase of the oedema is subsided, then an alteration of contour on the affected side is apparent. This is best seen by viewing the patient either from above(bird view ), by standing behind and above the patient and comparing both the sides of the face or by viewing it from below(worm view). 2- Unilateral epistaxis may be present. 3- Circumorbital ecchymosis will develop after few hours from effusion of blood into the surrounding tissues. 4- Circumorbital oedema can be quite gross. The examination of the eye may not be possible, till oedema subsides. 5- Subconjunctival haemorrhage will be observed at the outer canthus, if the patient is asked to look medially, the posterior limit of the effusion cannot be defined. Such an appearance is indicative of fracture of the lateral orbital wall or floor. 6- Depression of the ocular level. 7- Limitation of ocular movement may be seen. 8- Proptosis of the eye may be seen due to retrobulbar haemorrhage. 9- Patient may complain of diplopia and/or blurring of vision. 10- Anaesthesia of the cheek, nose and lip may be present. 11- Traumatic emphysema can often be detected in the infraorbital region, if air escapes into the tissues from the maxillary sinus. 12- Step deformity of the infraorbital margin. 3

4 13- Limitation of mandibular movement due to impingement of fractures segment on coronoid process. 14- Ecchymosis and tenderness in the upper buccal sulcus, change in sensation of the teeth and gums. 15- Enophthalmos may be seen. 16- Cranial nerves within the orbit may sustain damage. The sixth nerve is most frequently involved, sometimes the contents of the superior orbital fissure are all damaged, in which case ophthalmoplegia, dilation of the pupil and anaesthesia within the distribution of the ophthalmic branch of the fifth cranial nerve are noted. Rarely the orbital apex is fractured with resultant damage to the optic nerve and blindness. Radiographic examination Occipitomenton projection is the best projection for the complex. Diplopia It is a blurred, double vision experienced by the patient. It is a relatively common complication following fractures of the zygomatic complex. It can be: Temporary. Permanent nature. It is important to distinguish between two varieties of diplopia:- 1- Monocular diplopia 2- Binocular diplopia. Monocular Diplopia Double vision through one eye, with the other closed, requires the immediate attention of an ophthalmologist, as it indicates a detached lens or other traumatic injury of the globe. Binocular Diplopia Double vision when looking through both eyes simultaneously. It is common complaint and occurs in approximately in 10 to 40 per cent of zygomatic injuries. Diplopia can be caused due to the following: Causes of diplopia 1. Physical Interference a- Intramuscular haematoma or oedema of one or more of the extraocular muscles or around the region and this type is usually temporary. b- Disturbance to the attachment of inferior rectus or inferior oblique muscle. Prevent the upward and outward rotation of the eye. c- Herniation of periorbital fat into the maxillary sinus (orbital floor fracture that is called blow out fracture) this type should be followed closely after reduction of fractures segment. 4

5 d- Muscle or periorbital tissue entrapment in the fractured fragments (immediate and temporary diplopia) inferior oblique muscle is the most commonly affected. e- Development of fibrous adhesions and fat atrophy; (late and permanent diplopia) during posttraumatic healing. 2. Functional Interference Alteration of the ocular level depends on the level at which the fracture occurs in the lateral wall of the orbit. [The globe of the eye is supported by Lockwood s suspensory ligament, which is a fascial sling passing from the medial attachment in the region of the lacrimal bone, to be inserted laterally into Whitnall s tubercule, on the lateral wall of the orbit, just below the frontozygomatic suture]. If the fracture passes below Whitnall s tubercle, the zygomatic bone can be grossly displaced downward without alteration in the level of the globe of the eye. But if the fracture occurs above Whitnall s tubercle, then alteration of the optical axis results in diplopia. Alteration of ocular level is seen due to the fracture dislocation of the lateral orbital rim. The palpebral ligament is attached to the frontal process of the zygoma. Arrows show the downward displacement of the eye and the palpebral ligament, with displaced bone fragments 3. Neurological Causes Paralysis due to nerve injury or oedema. Intracranial injury. Superior orbital fissure or intraorbital damage. Testing the Motions of the Eye and Diplopia Hess chart, Movement of the eye can be tested by holding a finger or an object at least an arm s length in front of the eyes. The movement of the eye should be examined in all nine positions of the gaze. Simultaneously patient should be asked to report double vision as the finger is moved. The chart shows which of the extraocular muscles is functioning abnormally. Rapid improvement as shows on the Hess chart indicates that double vision was caused by temporary muscle oedema. If, however, the Hess chart remains unchanged in the first week, then the more permanent damage is suspected and future decisions for treatment can be taken. 5

6 Testing the motions of the eyes in all nine positions of gazes. The ninth gaze is the frontal gaze. At the same time diplopia and ocular level is also checked. Forced duction test Here a small tissue holding forceps is used to grasp the tendon of the inferior rectus muscle through the conjunctiva of the inferior fornix and the patient is asked for the entire range of motion. An inability to rotate the globe superiorly signifies entrapment of the muscles in the orbital floor Enophthalmos In simple word Enophthalmos is the inward sinking of the eye. It is a troublesome sequel to the fractures of the zygomatic complex. It occurs following injury due to following: 1- Loss/decrease of volume of orbital contents; herniation of orbital soft tissues in the maxillary sinus or medial wall. 2- Increase in the volume of the bony orbit due to fractures of its walls. Lateral and inferior displacement of the zygoma or disruption of the inferior and lateral orbital walls or both (can be appreciated by quantitative CT scan). 3- Post traumatic fibrosis, scar contraction and fat atrophy. 4- Combination of all these. Initially enophthalmos is difficult to diagnose in acute cases, as adjacent soft tissue oedema always produces relative enophthalmos. 6

7 Clinical Features of Enophthalmos 1- Accentuation of the upper eyelid hooding. 2- Anterior projection of the globe as viewed from above will be reduced on the side of the injury. Enophthalmos can be corrected by surgical intervention as soon as possible. There is always a difficulty to correct it secondarily because of the fibrosis. Surgery to reduce the orbital volume is done by placing a space occupying material behind the globe. Nonresorbable alloplastic materials such as Glass beads, silicone sheets and sponges, hydroxyapatite, Teflon can be used to maintain their bulk within the orbit. But there can be problem of extrusion, migration or infection. Autograft, Cartilage and bone grafts are more popular for rebuilding the orbital volume. Blindness Diminished vision or blindness is brought about by Retrobulbar haemorrhage. Laceration of the optic nerve or haemorrhage into the optic nerve itself. Retrobulbar haemorrhage will bring about temporary blindness or diminished vision. There will be proptosis, retrobulbar pain and dilation of the pupil and ophthalmoplegia. Initial conservative treatment will lead to gradual absorption of haemorrhage and full range of motion with gaining the vision will be seen within several weeks. The conservative treatment will consist of ice application, sedative, bed rest, diuretics as IV mannitol and high doses of systemic steroids 3 mg/kg of dexamethasone every 6 hourly Proptosis of the right eye caused by a retrobulbar haemorrhage due to fracture of the zygomatic bone, (2) Swelling and ptosis of the right eyelids due to lymphatic obstruction and injury to the levator muscles 7

8 (1)Typical subconjunctival ecchymosis in a case of zygomatic bone fracture. Note the oedema of the eyelids, (2) Forcible separation of the eyelids and patient is asked to look medially. Subconjunctival haemorrhage is seen at the outer canthus. Note that the posterior limit of the effusion cannot be defined, (3) Coronal CT scan showing the fracture of the lateral orbital wall and the floor and left zygomatic bone. Note the displacement of the bones and haziness of the left maxillary sinus Treatment of Fractures of the Zygomatic Bone In majority of cases early operation is advisable, provided that there are no ophthalmic or cranial complications. Whenever there is a gross periorbital oedema and ecchymosis, postponement of the operation for 3 to 5 days can be done, but it should not be prolonged more than two weeks. Stable fractures Simple elevation will be sufficient, because of high degree of stability due to integrity of temporal fascia and the interdigitation of the fracture lines. No additional fixation is required after reduction. Unstable fractures Require open reduction and transosseous wiring or bone plating. Operative Technique The approaches of Gillies, Kilner and Stone are popular for reduction of fractures of zygoma. Facial depression seen due to V-shaped fracture of zygomatic arch 8

9 Gillies Temporal Approach The temporal fascia is attached to the zygomatic arch and the temporal muscle passes downward medial to the fascia to be attached to the coronoid process. Between these two structures a natural anatomical space exists into which an instrument can be inserted and it can be utilized to elevate the displaced zygoma or its arch into position. Technique The hair is shaved from the temporal region of the scalp. The external auditory meatus is plugged with cotton to prevent any fluid or blood getting inside. An incision about 2 to 2.5 cm in length is made, inclined forward at an angle of 45 degrees to the zygomatic arch, well in the temporal region. Care is taken to avoid injury to the superficial temporal vessels. The temporal fascia is exposed which can be identified as white glistening structure. The incision is taken into the fascia and the fibres of temporalis muscles will be seen. Long Bristow s periosteal elevator is passed below the fascia and above the muscle. Once this correct plane is identified and instrument is inserted through it downward and forward, the tip of the instrument is adjusted medially to the displaced fragment. The tip of the elevator is manipulated upward, forward and outward. The snap sound will be heard as soon as reduction procedure is complete. Wound is closed in layers after withdrawing the elevator. Care is taken that after surgery at least for 5 to 7 days, no pressure is exerted on the area till the bone consolidates. While the tip of the elevator rests on the medial surface of the zygomatic bone, the operator should keep on palpating the external contour with the hand and guide the manipulation till proper positioning of the fragments is achieved. Patient is instructed to sleep in supine position or not to sleep on the operated side. Gillie s temporal approach for reduction of zygomatic bone/arch fracture: (1) Temporalis fascia, (2) Temporalis muscle 9

10 Keen s approach Intraoral Procedure: Introral buccal vestibular incision is taken in first and second molar region behind the zygomatic buttress. A pointed curved elevator (Monks pattern) is passed supraperiosteally up beneath the zygomatic bone. The depressed bone is then elevated with an upward, forward and outward movement. Direct extraoral elevation can be done by inserting a sharp curved hook directly through the skin below and above the prominence of the zygomatic bone. Manipulation of the hook reduces the fracture. 10

11 Intraoral Keen s approach for reduction of zygomatic bone/arch fracture Reduction of zygoma using zygomatic hook. Closed reduction of zygomatic bone fracture using towel clip Reduction of zygomatic arch fracture by Gillies method: (1) Typical depression due to depressed V shaped fracture of R zygomatic arch, (2) Limited oral opening due to impingement on the coronoid process by fractured fragments, (3) Jug handle X-ray views 11

12 showing fracture of R zygomatic arch, (4) Reduction by Gillies method, (5) Improved oral opening after reduction Gross separation of the zygomaticofrontal suture : Extraoral incision is taken in the wrinkles, one centimeter above the outer canthus or in the line of the outer aspect of the eyebrow. Holes are drilled approximately 0.5 cm away from the fracture ends of the frontal and zygomatic bones. A periosteal elevator is placed on the medial aspect to protect the eye. The 26 gauge double wire is passed and twisted after passing through both the holes and approximation of the fragments. Instead of wire, 2 Hole miniplates can also be used for direct fixation. Wound is closed in layers. (1) PA view Water s showing gross displacement of both R and L zygomatic complex and nasal bones, (2) Surgical exposure of right side fractured frontal process of zygoma, (3) Fixation after reduction with intraosseous wiring on right side, (4) Surgical exposure on the left 12

13 side frontal process of zygoma showing loss of bone, (5) Autogenous iliac crest bone grafting done (1) Typical appearance following fracture of the R zygomatic bone after dispersal of the initial oedema. Note the loss of contour and flattening on right side of the face, (2) Gillies approach for reduction, (3 and 4) Open reduction via infraorbital incision for reduction of infraorbital rim fracture and fixation by intraosseous wiring, (5) Postoperative facial appearance Malunion of the Zygomaticomaxillary Complex It will show following signs and symptoms. 1- Cosmetic; Loss of contour or prominence of cheek will be seen. Correction may be done either by surgical refracturing or camouflaging the deformity by means of onlay bone grafting or alloplastic material like hydroxylapatite blocks. 2- Neurological; The paraesthesia, dysaesthesia or anaesthesia may be present. Observation for recovery of infraorbital nerve should be done for 6-12 months, otherwise surgical exploration of the nerve can be done. 3- Antral; Persistent sinusitis may be due to the presence of loose necrotic bone pieces or a foreign body which should be removed via Caldwell-Luc operation. 4- Masticatory; Depressed zygomatic arch fracture impinges on the coronoid process bringing about limitation of the mandibular movements and opening. 5- Ophthalmic;Change of the ocular level, diplopia, enophthalmos, occulorotatory restriction are the residual deformities which are difficult to correct secondarily. Exploration and surgical correction can be attempted. In extensive fracture, via coronal incision the arch should be exposed, refractured and stabilized by direct fixation method. Osteotomy and bone grafting can be done if required. 13

14 Fracture of the Floor of the Orbit (Blow-out Fracture) True blow-out fracture occurs as a result of direct trauma to the orbit with an object larger than the globe size (cricket ball injury). Blow-out fracture of the floor of the orbit. A tennis ball aimed at the globe of the eye forces it posteriorly, compressing the periorbital fat and fracturing the thin orbital floor. Fractured fragments and herniation of periorbital fat will be seen in the maxillary sinus Here primarily there is an increase in hydraulic pressure within the orbit resulting from compression of the orbital contents with fractured orbital floor. At the same time, orbital fatty tissue and sometimes muscles, (inferior rectus and inferior oblique) prolapse into the sinus like a hernia. The infraorbital rim remains intact. The fracture may go unnoticed due to the presence of orbital, periorbital oedema, haematoma and the clinically intact infraorbital ridge. Fractured orbital floor may be associated with enophthalmos with restriction of the extraocular movements and at times diplopia may be present. Diagnosis can be confirmed by forced duction test and by hanging drop appearance in PA view Water s position radiograph or by CT scan. 14

15 1) Coronal CT scan showing trapdoor deformity indicating blow-out fracture of R orbital floor. (2) Hanging drop appearance in L maxillary sinus indicating herniation of orbital contents in the sinus due to blow-out fracture Coronal CT scan showing the blow-out fracture of the floor of the orbit. Herniation is seen in the maxillary sinus Treatment: Surgical exploration of orbital floor and reconstruction of the orbital floor by Silastic sheet or bone graft whenever necessary. Otherwise balloon support or ribbon gauze packing can be used in the maxillary sinus when there is comminution. Comminution and displacement of the orbital rim Direct figure of eight intraosseous wiring can be done through infraorbital incision or orbital plate can be fixed. 15

16 Various skeletal incisions for exposure of midface skeleton are follows: 1. Supraorbital eyebrow incison 2. Subciliary incision 3. Median lower eyelid incision 4. Infraorbital incision 5. Transconjunctival incision 6. Zygomatic arch incision 7. Transverse nasal incision 8. Vertical nasal incision 9. Medial orbital incision. 16