Mid facial fracture/ dental implant courses by Indian dental academy by indiandentalacademy

GITAM DENTAL COLLEGE & HOSPITAL

DEPARTMENT OF ORAL & MAXILLOFACIAL SURGERY

SEMINAR ON Midfacial fractures Presented By: Dr. Sambhav K Vora III MDS

CONTENTS I.

INTRODUCTION

II.

DEFINITION

III.

HISTORY

IV.

MIDDLE THIRD BONES

PHYSICAL CHARACTERISTICS

VI. VII. VIII. IX. X.

ARTICULATION WITH BASE OF SKULL BIOMECHANICS CLASSIFICATIONS LE-FORT I,II,III FRACTURES PALATAL FRACTURES

XI.

EXAMINATION

XII.

MANAGEMENT

XIII.

VIEWING OF IMAGES

XIV.

CLASSIFICATION

METHODS

MAX.FRACTURE

FIXATION XV. XVI. XVII. XVIII.

USE OF DIFFERENT TYPES OF INTERNAL WIRE SUSPENSION FIXATION TECHNIQUES SURGICAL APPROACHES TO EXPOSURE OF MAXILLA COMPLICATIONS

XIX.

CONCLUSION

XX.

REFERENCES

INTRODUCTION Fractures of the maxilla and associated bones were commonly referred to as fracture of the middle third of the facial skeleton. The reconstruction of

the midface

following trauma

demands

uncompromising care. The phase is intimately related to self image. It is the region responsible for our sense of smell,vision & for providing our voice & its resonance through the presence of air sinuses. DEFINITION OF MIDDLE ONE THIRD OF THE FACE: The middle third of facial skeleton is defined as an area bounded superiorly by a line drawn across the skull from zygomaticofrontal suture across the frontonasal and frontomaxillary sutures to zygomaticofrontal sutures on the opposite side and inferiorly by the occlusal plane of the upper teeth. It also extends backwards as far as the frontal bone above and the body of sphenoid below and pterygoid plates of the sphenoid below MIDDLE THIRD OF FACIAL SKELETON IS MADE OF:

•

Maxillae

•

Zygomatic bones

•

Zygomatic process of temporal bones

Paired bones

•

Palatine bones

•

Nasal bones

•

Lacrimal bones

•

Vomer

•

Ethmoid and its attached conchae

•

Two inferior conchae

•

Pterygoid plates of sphenoid

The relative fragility of the mid-facial skeleton acts as a cushion for trauma directed towards the cranium from an anterior or anterolateral direction. ARTICULATION WITH THE BASE OF THE SKULL: It is known that the frontal bone and body of sphenoid form an inclined plane which slopes downwards and backwards from the frontal bone at an angle of about 45° to occlusal plane of upper teeth. The bones of the middle third of facial skeleton articulate with these strong foundation bones and when fracture occurs there is backward and downward displacement causing the posterior teeth and maxillae to push open the mandible producing a gagging of occlusion posteriorly. In extreme cases the soft palate may be pushed down upon the dorsum of the tongue causing embarrassment to the airway. The fractures usually follow the lines of weakness within the face described classically Guerin (1866) and Lefort (1901).

CLASSIFICATION: A.

FRACTURES NOT INVOLVING OCCLUSION:

Central Region:

Fractures of the nasal bones/nasal septum.

Lateral nasal injuries Anterior nasal injuries b. Fractures of frontal process of maxilla c. Nasoethmoidal fractures d. Fractures of type (a), (b) and (c) extending into the frontal bone (frontoorbitonasal dislocation). II. Lateral region: Fractures involving the zygomatic bone, arch and maxilla excluding dentoalveolar component. B. Fractures involving the occlusion : Dentoalveolar Subzygomatic -

Lefort I (low level or Guerin)

Lefort II (Pyramidal Fracture)

Suprazygomatic -

Lefort III (High level or craniofacial dysfunction)

MODIFIED LEFORT FRACTURE CLASSIFICATION : LeFort Level I

Description Low maxillary fracture

Low maxillary fracture with multiple segments

Pyramidal fracture and nasal fracture

IIb

Pyramidal and NOE fracture

III

Craniofacial dysjunction

IIIa

Craniofacial dysjunction and nasal fracture

IIIb

Craniofacial dysjunction and NOE

Lefort II or III fracture& cranial base

IV a

+ supra orbital rim fracture

IV b

fracture

+ anterior cranial fossa and supra orbital rim

fracture IV c

+ anterior cranial fossa and orbital wall fracture

FRACTURE PATTERNS Rene Lefort -1901 gave a classification based on his study of the lines of weakness present on the human skull.

LeFort I: A horizontal fracture above the level of the nasal floor. The fracture line extends backwards from the lateral margin of the anterior nasal aperture below the zygomatic buttress to cross the lower third of the pterygoid laminae. The fracture also passes along the lateral wall of the nose and the lower third of the nasal septum to join the lateral fracture behind the tuberosity.

LeFort II: Fracture runs from the middle area of the nasal bones down either side, crossing the frontal process of the maxillae into the medial wall 8

of each orbit. Within each orbit the fracture line crosses the lacrimal bone behind the lacrimal sac before turning forward to cross the infraorbital margin slightly medial to or through the infraorbital foramen. The fracture now extends downwards and backwards across the lateral wall of the antrum below the zygomatico maxillary suture and divides the pterygoid laminae about half way up.

Lefort III: The fracture runs from near the frontonasal suture transversely backwards, parallel with the base of the skull and involves the full depth of the ethmoid bone, including the cribriform plate within the orbit the fracture passes along below the optic foramen into the posterior limit of the inferior orbital fissure. From the base of the inferior orbital fissure the fracture line extends in two direction; backwards across the pterygomaxillary fissure to fracture the roots of the pterygoid laminae and laterally across the lateral wall of the orbit separating the zygomatic bone from the frontal bone.

Stanley and Nowak (1985) in a cephalometric study of cadaver facial impacts stressed the importance of the angle of impact in relation to the horizontal buttresses of the facial skeleton. Impacts on the nasion at 30째-60째 above the horizontal are likely to cause a Lefort III fracture. A horizontal impact whose vector is in the horizontal orbitomental plane tends to cause LeFort II fracture. Impacts below the anterior nasal spine tends to detach the hard palate and maxillary alveoli from the nest of the midface. This time honored classification does not provide full description of the degrees of comminution and displacement, nor does it mention two commonly associated and very important lesions the parasaggital fracture of the upper jaw. Furthermore the severity of maxillary fracture to other areas of the craniofacial skeleton.

Cooter S.David (1989) classified the fracture of the facial skeleton. Main bones of the skull was classed as (Major zones) and the sutures, various bone parts are classed as (Minor Zones). In case of maxilla. Major Zone : Maxillary bone as a whole. Major code of maxilla : MX. Minor zone : Anterior wall of maxilla, buttresses, palate, dentoalveolar and pterygoid. Minor code : MxA, MxB, MxP, MxD, MxT. Severity of Fracture: No fracture

Undisplaced fracture

Obviously displaced fracture

Comminuted/Compound fracture

BIOMECHANICS â&#x20AC;˘

Buttresses form basic vertical and horizontal framework for facial skeleton

•

Imp. Facial structures – orbit and paranasal sinuses are surrounded by buttresses

•

Manson et.al

•

4 vertical –

3 bilateral. Peripheral 1 central

•

3 horizontal

•

Withstand vertically directed forces

•

Poorly suited – horizontally or ventrally directed forces

VERTICAL BUTTRESSES 3 Bil peripheral : Nasofrontal buttress Frontal process of maxilla Nasal bones Nasofrontal suture Med.wall of max.sinus & orbits

Forms a bridge between anterior hard palate and frontal bone zygomatic buttress body of zygoma and its frontal process transmit forces from mid-maxilla to frontal bone pterygomaxillary buttress pterygoid process & plates of sphenoid bone posterolateral & posteromedial walls of adjacent maxillary sinus transmit forces from posterior hard palate and alveolar ridges to the base of skull

Central

Nasoethmoid Buttress Ethmoid Vomer Forms

important

osseous

lower facial skeleton and the cranium

Bone bridge

between

HORIZONTAL BUTTRESS *

Superior buttress orbital plate of frontal bone

cribriform plate of ethmoid bone *

Middle buttress zygomatic process of temporal bone body & temporal process of zygoma infraorbital process of zygoma orbital surface of maxilla segments of frontal process of maxilla provides lateral stability to facial skeleton protects central facial skeleton from horizontally directed forces

Inferior buttress alveolar ridge hard palate acts as important stabilizing bridge between the two maxillary bones

CLINICAL FEATURES OF INDIVIDUAL FRACTURE :

LEFORT I, LOW LEVEL OR GUERIN TYPE FRACTURE : May occur as a single entity or in association with Lefort II and III fractures. A Lefort I fracture which often escapes diagnosis is the impacted type which results from violence transmitted via a blow to the lower jaw and is often therefore associated with a fracture of the mandible. It is possible to see the condition unilaterally when it involves only one maxilla, the tooth bearing portion being split along the median palatal suture. Clinical Features: Upper lip laceration, loose or fracture maxillary incisors. Airway obstruction - (+/-) Edema of the upper lip and (laceration +/-) Lengthening of the face - may or may not be present depending whether the fracture is impacted or not. Epistaxis-(+ve) Nasal septal deformity may or may not be present Impacted type of fracture may almost be immobile but implication will be present, usually caused from trauma transmitted via a blow to lower jaw where lower teeth come and hit against the maxillary teeth. Occlusion is disturbed and a variable amount of mobility may be found in tooth bearing segment of maxilla due to dentoalveolar fracture if present. Echymosis will be present in buccal vestibule. On percussion of the upper teeth there will be distinctive cracked pot sound. ln case of a fracture coursing through the palatal suture line or adjacent to it a palatal echymotic area is usually noted.

SYMPTOMS: Initial hemorrhage from nose or mouth. Teeth meet abnormally. Pain on mastication. Maxillary mobility with swallowing. Trismus Nasal obstruction, upper airway obstruction Dysphagia SIGNS: Lip laceration, lose or fractured maxillary incisors. Lower maxillary asymmetry, malocclusion Gingivobuccal sulcus echymosis of tenderness Septal tear or dislocation Facial elongation, cracked pot sound Subcutaneous emphysema and crepitus Oropharyngeal edema and hematoma Opaque antrum on transillumination Radiographs: OPT, PA skull. Lateral skull, PNS.

LeFort II or Pyramidal Fracture : Referred to as a pyramidal fracture with the apex of the pyramid being the nasofrontal suture.

Classic manifestation of this fracture is bilateral

periorbital edema at times accompanied by echymosis giving rise to Racoon's sign. Clinical Features: Gross oedema of the middle third of facial keleton. 19

1) Airway obstruction

2) Cerebrospinal fluid leak

3) Crepitus

4) Decreased extraocular muscle function

5) Diplopia

6) Echymosis, buccal vestibule

7) Periorbital echymosis

8) Subconjuctival echymosis

9) Enopthalmoid

10) Bilateral epistaxis

11) Infra orbital rim defect

12) Lengthening of the face with disk face deformity : + (Moon face) 13) Malocclusion

14) Medial canthal defomuty

15) Nasal septal defoimity

16) Pupil height, unequal

17) Lateral orbital rim defect 18) Anaesthesia/Parasthesia of tile cheek

: :

(-)

19) Posterior gagging of occlusion due to retropositioning of maxilla: + Radiographs : PA skull, Submentovertex, Labial skull. Water view, CT Scan.

LE FORT III : Also called as the craniofacial dysfimction. The symptoms are classic dish face and the mobility of2ygomaticomaxiUary complex. Gross oedema of the soft tissues over the middle third of the facial skeleton (+) 20

Airway obstruction (±) Cerebrospinal fluid leak (±) Crepitus (+) Decreased extraocular function (±) Diplopia(±) Periorbital echymosis(+) Subconjunctival echymosis (+) Endopthalmos(±) Bilateral epistaxis (+) Labial orbital rim defect (+) lengthening of face (±) Trismus (±) Malocclusion (+) Medial canthal deformity (±) Nasal septal deformity (±) Parasthesia of anterior cheek (+) Pupil height unequal (±) Epiphora (±) Telecanthus (±) Radiographs : PA skull, Submentovertex, Lateral skull. Water's view, CT scan. Airway obstruction with stridor or dysphagia may arise from either sagging of the soft palate against the tongue or posterior oropharyngeal wall edema or hematoma caused by sudden impact of the posterior margin of the hard palate against the cervical spine, also it may be due to presence of clots and debris like bone or tooth fragments. 21

In some cases the direction of the traumatizing force and subsequent pull of both gravity, pterygoid muscle action and superior constrictor muscle combine to produce a degree of posterior displacement and inferior tipping of the fragments. Lengthening of the face can be then if fracture fragments is free floating and percussion of teeth will have cracked pot sound. In LeFort III fracture due to bilateral separation of frontozygomatic sutures causing lengthening of the face and lowering of the fracture fragment bilaterally and lowering of the occular level due to fracture passing above the withnall's tubercle removing the support given to the eye by suspensory ligament oflockwood. A para saggital split usually occurs in 10% of LeFort fracture. The fracture line is usually within I cm of but not within the midline. The vomer strengthens the midline of the palate and the alveolar process provides the bulk laterally. Therefore the fracture is through the thin bone just off the saggital plane. Therefore a linear echymosis of the overlying mucosa fracture line may be palpable and two side can be moved independently. CSF RHINORRHEA : CSF rhinorrhea results from a breakdown of the dura and supporting structures of the skull base resulting in a connection between the subarachnoid space and the nose. It may be a complication of trauma, tumor ablation, paranasal sinus disease, or surgery. Regardless of etiology, the mechanism is essentially the same. There is a disruption of the arachnoid and the dura, coupled with an osseous defect, and a CSF pressure gradient that is either continuously or intermittently greater than the healing tensile 22

strength of the disrupted tissue. This causes separation of the dural fibers and CSF leakage. CSF rhinorrhea may occur directly through the anterior cranial fossa or indirectly from the middle or posterior fossa via the Eustachian tube. More specifically, these portals of entry may take place across the frontal sinus, cribriform plate of the ethmoid, the sphenoid sinus, the sella, or via the temporal bone from the middle ear and through the Eustachian tube. C.S.F. OTORRHEA: If an intact tympanic membrane ruptures (CSF) fluid will leak out of the ear resulting in (CSF) otorrhea. Loss of hearing is frequently associated with collection of fluid in the middle ear cleft. Anosmia is associated with tear in the area of the cribriform plate. If this symptom can be localized to one side of the nasal fossa or the other it can sometimes be of value in localizing the leak problem. If (CSF) rhinorrhea is straight forward if the fluid is not mixed with blood, nasal secretions or lacrimal secretions it should be collected in a vial and if glucose level analysis of 45 mg/dl confirms (C.S.F.). Glucose (mmoles/lit) Protein (g/lit) K (Mmoles/Lit)

CSF 2.5-3.9 <0.5 2.5-3.5

Nasal Secretions 0.6-1.4 >2 12-26

Serum 3.5-52 60-85 3.3-4.8

C.S.F. will not stiffen a hand kerchief, while nasal secretion will do so. C.S.F. will also form characteristic concentric rings when poured on linen or tissue paper. Patient should be questions about any salty taste. It should be noted that absence of leakage does not imply the absence of leakage does not imply the absence of a tear of dura. Meningitis is the inherent risk is a basal skull fracture with a concomitant dural tear. Mulec reported a case of cerebrospinal fluid rhinorrhea 12 years following injury. The presence of a basilar skull fracture with a dural tear is not a contraindication to the reduction of midface fractures. On contrary a mobile midface often creates a pumping action that results in increased CSF leakage. Early reduction and immobilization are therefore indicated. Epiphora : Post-Traumatic Enopthalmos : Diplopia : Hooding of the Eye : The suspensory ligament of Lockwood which is a fascial sling posses from medial attachment in the region of the lacrimal bone to be inserted laterally into whitnall tubercle on the lateral wall of the orbit just below the frontozygomatic suture. If fracture posses above the Whitnalis tubercle the zygomatic bone is displayed downwards and the upper eyelid follows it causing a characteristic hoarding of the eye. Anaesthesia/Parasthesia : Of the anterior cheek can be can be due to trauma to the infraorbital nerve. Subsequent oedema of the middle 3nl of the face also contributes to parasthesia of that region. 24

POST-TRAUMATIC TELECANTHUS : Medial canthal ligament is attached to the anterior and posterior lacrimal crest. Any injury due to trauma to the nasoethmoidal area causing fracture of the bones with comminution the fracture fragments will spread laterally into the orbital space. Comminution of the lacrimal bone or avulsion of ligaments from the lacrimal crest or direct laceration of die medial canthus would cause displacement of medial canthal ligament laterally. The tension exerted by the orbicularis oculi muscle, now unchecked due to displacement of (M.C.L.) well result in rounding of the medical canthus and a shortening of the horizontal palpebral fissure. Lateral migration of the canthus will than obscure the camucnie and alter the angle set by the lids at the medial canthus, detachment of Homer's muscles which maintains the backward pull of the lid will cause a laxity and excessive scleral show. Measuring the interpupillary distance and dividing it by half will give us the approximate intercanthal distance. Telecanthus thus is the term applied for widening of the medial canthus.

HYPERTELORISM : Is the term applied for bony displacement of the whole orbit (usually observed with a congenital bone deformity). Normal intraorbital distance i.e. distance between medial walls of the orbit) is usually less than 25 mm in the adult female and 28 mm in adult male. VIEWING THE IMAGES Mc gregor and Campbell (1950) described rgstem for examining the OM view by following four lines : 1.

the first line: run across the zygomatic frontal sutures ,the frontal sinuses and the superior margins of the orbit.

the second line: runs along the zygomatic arches,the inferior margins of the orbits and the nasal bones

the third line: crosses the mandibular condyles and coronoid process and the maxillary sinus

the fourth line runs along the occlusal plane of the teeth and crosses the mandibular rami.

Trapnell (1985) added a fifth line which runs along the inferior border of the mandible.

DOLAN’S

LINES

FOR

THE

MODIFIED

CAUD

WELL

PROJECTION:

•

the first extends along the outer margin of the orbital process of the frontal and zygomatic bones

•

the second line is the innominate line or oblique orbital line

•

the third extends along the inner margin of the orbit down to break into 2 roughly parallel lines meeting at the inferior orbital fissure . the line then continues along the orbital margin inferiorly ,internally and superiorly

•

the fourth runs along the occlusal plane of the teeth and crosses the mandibular rami.

Dolans lines for the OM projection:

the â&#x20AC;&#x153;orbital lineâ&#x20AC;?: extends along the inner margins of the lateral, inferior & medial walls of the orbit ,passing over the nasal arch to follow same structure on the opposite side.

the zygomatic line: extends along the superior margin of the arch and body of the zygoma passing along the lateral margin of the frontal process of the zygoma to the zygomatic frontal suture

the maxillary line: extends along the inferior margin of the zygomatic arch, the inferior margin of the body and buttress of the zygome and the lateral wall of the maxillary sinus.

PALATAL FRACTURES: Fractures of the palate present a unique challenge to the surgeon skilled in conventional management of mid fractures. These

unstable

fractures are an Infrequent finding in the maxillotacial trauma patient. Most often palatal fractures are associated with other fractures of the midrace. They are found 8% of Le Fort fractures, and rarely are they found as an isolated fracture.To ensure proper postoperative stability and restoration of preinjury occlusion, a staged surgical approach is required for each class or palatal fracture. DIAGNOSIS Today with many trauma centers equipped with highly accurate CT scanners, few palatal fractures go undiagnoscd. This imaging modality is especially important in diagnosing those palatal fractures that are not associated with any clinical signs indicative of this type of fracture. Most patients having palatal fracture will demonstrate clear signs and symptoms. In up to 65% of palatal fractures, the patient will demonstrate a laceration of the lip, with 45% concurrently possessing both palatal and 32

gingival mucosal disruption.15 A change in the maxillomandibular occlusal relationship is also a reliable indicator. Segments of a fractured palate arc most often found to be displaced in both an anterior and a lateral direction. l6 The surgeon should be cautioned against using occlusion as an indicator of the presence of a palatal fracture, because the fracture may be masked by a concurrent mandible fracture, which itself produces marked rotation and displacement of its fractured fragments. CLASSIFICATION Six patterns of palatal fractures have been dccribedls based on their relationship with the maxillary alveolus, teeth, and palatal midlinc Type I—Alveolar fracture (2 types) Type la—Anterior alveolus—contains only the incisor teeth and alveolus in that region Type Ib—Posterolateral—contains premolars, molars, and alveolus in that region Type II—Sagittal fracture Type II fractures occur as a midline split of the palate. These types are found with the most frequency in the second to third decade because of a lack of an ossified midline palatal suture. Type III—Parasagittal fracture Most common fracture found in adults (63%) because of the thinner palatal bone located parasagittally.These fractures are differentiated from type Ib fractures because they contain the canine in addition to the premolars and molars. Type IV—Paraalveolar fracture Found directly palatal to the maxillary alveolus and also contains the incisor dentition. 33

Type Vâ&#x20AC;&#x201D;Complex/comminuted fracture Multiple large, obliquely oriented fracture segments or gross comminution Type VI--â&#x20AC;&#x201D;Transverse The rarest palatal fracture found, ir divides the maxilla in a coronal plane.

TREATMENT The approach to surgical treatment of palatal fractures begins with the identification of the specific type of fracture, state of the dentition, and associated maxil-larv or mandibular fractures. Predictable treatment is performed when using the combination of rigid internal fixation, application of arch bars, and a palatal acrylic splint in complex fractures. 34

MANAGEMENT :

Once the (ABC) of primary trauma management has been satisfied and after a history has been noted the initial clinical examination is done, starting with a brief visual inspection of the facial structure followed by palpation to locate any evidence of fractures. Radiology plays a critical role in the precise diagnosis of fractures. Additional information can be obtained with (CT) scanning. Bleeding from laceration must be controlled by pressure or placing sutures at the site. Bleeding from the ear can be due to associated condylar fractures causing laceration along the anterior wall of the canal. A perforation or bluging of the tympanic membrane usually indicates a basillar skull fracture. Subconjunctival haemorrhage reflects an orbital or periorbital injury.

Of similar

importance is the evaluation of the nose particularly the septum which may have septal haematoma if present haematoma should be trained to avoid septal necrosis and ultimately development of septal perforation. Even watchout for CSF rhinorrhea which results from the fracture involving the base of the skull and escape of CSF to either the ethmoid, sphenoid, frontal sinus or cribriform plate areas. Bilateral periorbital echymosis is commonly seen as a result of fracture of the base of the anterior cranial fossa and also is known as the racoons sign. Echymosis in the buccal fold frequency indicates a fracture of the maxilla of the zygoma or in an isolated fracture of the lateral wall of the maxillary sinus.

Crackling sound in the subcutaneous tissue indicates

subcutaneous emphysema which may be due to the passage of air throughout the fractured wall of maxillary sinus. Test for infraorbital nerve anesthesia as the nerve can be damage in case of Lefort II or as a result of orbital blow out fractures. Anosmia as a result of midfacial fracture involving the cribriform plate may occur , this may be due to 37

the transsection of olfactory nerves and can be permanent.

Injury to

the intracranial course of occulomotor nerve resulting in compression of the nerve may lead to dilated peoples indicating the cranial nerve III dysfunction. Lateral rectus muscle dysfunction or lateral gaze dysfunction usually indicates involvement of abducent nerve. Fracture of bones surrounding the optic foramen results in compression of optic nerve. In unconscious patient optic and occulomotor nerve function can be evaluated by using the consensual light reflex. Echymosis in the maxillary buccal fold and a class III open bite malocclusion are indicative of maxillary fracture. A direction and force of injury usually drives the maxilla posteriorly and inferiorly resulting in this occlusal deformity.

Nasofrontal suture region should be palpated firmly when

the maxilla is manipulated to exclude Lefrot II and Lefort III maxillary fractures. The thumb and index finger can be used for palpation in the buccal fold region as the maxillary is manipulated by placing one hand on the forehead while manipulating the maxilla with other. Lack of maxillary mobility does not exclude a maxillary fracture always depending on the direction and force of injury a maxillary fracture may be significantly impacted and mobilization may be possible only after the patient has been anesthetized and disimpaction forceps has been used. Significant displacement of lateral orbital rim may result in diplopia secondary to displacement of the lateral canthal ligament. Patient's visual acquity and extraocular movements must be reevaluated as a part of periorbital examination. Intraoral palpation of the buttress may disclose a step deformity. Intracanthal width normal 30 to 30 mm although slight racial variation exists, measurement beyond 32 mm generally indicates the presence of traumatic 38

telecanthus. Although traumatic telecanthus is not associated with diplopia or other regional changes it would result in cosmetic deformity. The triad of a flattened nasal bridge, and obtuse medial canthal angle and increased intercanthal angle should alert the clinician to tile presence of deformity.

Palpation of nasofrontal suture will

reveal repetition and pulling the soft tissue laterally into the lateral canthal angle region results in rounded or semi lunar crease rather than a sharp canthal angle. Traumatic telecanthus is easily differentiated from hypertelorism in which the interpupillary distance is increased normally 60 to 65 mm. Hypertelorism is generally seen in congenital deformities such as Crouzon's disease and Apert's syndrome and rarely is a result of trauma. Large number of muscles attached to the walls of the maxilla but these insert only into the skin and do not contribute to the deformity of the fracture. Perigoid muscles in case of Lefort fractures usually act on die fracture fragments and pull them posteriorly and laterally.

Intraorally after checking for mucosal lacerations,

subrnucosal echymosis, status of teeth, integrity of palate and upper alveolus should be evaluated. A split palate may be often be associated with laceration and separation of alveolar rim. Premature contact of molar teeth and an openbite deformity is due to displacement of the whole maxilla backward and 2< downwards. Whereas crossbites are apparent with lateral displacement of the maxilla in case of a split palate.

The examination is usually carried out with a gloved finger which is passed on to the hard palate exerting an upward and rocking force which may elicited pain, crepitus and abnormal mobility. Further examination of other sites using bimanual palpation at pyriform base and nasofrontal and fronto-zygomatic suture areas in turn while applying upward rocking force to the hard palate. In some cases of patients with gross midface instability can be demonstrated by asking the patient to bite upwards with his mandible resulting in upward movement of the upper jaw. Preoperative planning of whether open or closed method one to be employed, following this decision the type of fixations selected following which the necessity for and type of intermaxillary fixation depending upon the condition of the teeth, presence of alveolar or palatal fractures will influence the choice between interdental eyelet wires, arch bars, gunning type of splints. Usually the surgery may be delayed until the patient's condition has been stabilized and the swelling has largely settled though many controversies are present regarding early or late management. TREATMENT : As in the treatment of any other fracture the objective with a fracture of the middle of the face is to achieve reduction followed by an adequate period of fixation to ensure stable union.

Facial skeleton can be broadly divided into three concentric rings. The outer ring or framework of the face is reconstructed first by reducing the frontal bone and orbital roof, zygomatic complex on each side and establishing a mandibular platform below. Now the central block can be reduced and mixed within it utilizing the occlusion below and direct fixation to the cranium above. The most control ring comprises of the nasal complex on each side. After using the mandible as a guide to accurate reduction, the middle third must be immobilized by attaching it to a fixed point on the vault of the skull. Treatment of Unilateral Maxillary Fracture : If fracture fragment is mobile digital pressure may be utilized to reduce the fracture. The teeth in fracture segment are first loosely wired to the maxillary arch bar. The teeth in the unfractured segment are securely ligated (I.M.F.) is carried out on the unfractured site and completed on the fractured side after reduction and lightening of interdental wires of that fragment (IMF) is released after 4 weeks by which time satisfactory stabilization will have observed.

Occlusal splints can also be used.

Arch bars are placed on both

maxillary arches. The maxillary bar is cut at the line of fracture. The interdental splint is wired first to stable fragment and the fracture portion of arch is manually reduced into the splint and secured with a 24 gauge wire. The mandible is then positively guided into the splint and (IMF) is completed. Reduction is usually attamed with minimal difficulty especially if carried out soon after the injury. On occasional, impacted fracture are encountered which may not be responsive to digital manipulation. Here Rowe's disimpaction forceps is an excellent tool for achieving reduction. An open reduction may be utilized if fracture fragment appears to be unstable following attempted reduction. An open reduction may be utilized if fracture fragment appears to be unstable following attempted reduction. In this case application of arch bans and an occlusal splint is necessary prior to the placement of interossoeus wiring or bone plates. With rigid fixation in place there is no need for the patient endure (I.M.F.). Teeth in the line of fracture are lefr in place unless there is excessive mobility or unless the fracture has occurred through the coronal 2/3'd of the tooth. An edentulous minimally fracture hemimaxilla demands only digital reduction of the garments. However when the fractured fragment contains teeth and the unfractured one is edentulous, therapy comprises an open reduction and the use of interosseous wiring or semirigid plate fixation.

An early reduction of fracture as a rule presents minimal difficulty. Beyond 7 to 10 days increasing force has to be applied to complete a reduction. A minimally displaced fracture is reduced and immobilized by intermaxillary wire fixation. One month of immobilization is usually sufficient for healing to occur. In the case of severe commination it may be necessary to extend the period I to 6 weeks. An impacted fracture one not easily reduced because of early fibrous union should treated by die use of either a Rowes or Hayton Williams disimpactions forceps the beaks of the Rowes forceps are placed along the nasal floor and against the palate. They are used a pair or singly. To protect the nasal mucosa and the palatal mucoperiosteum, it is wise to place rubber tips on the beaks. By means of a rocking and rotating motion will usually recalcitrant maxilla. An open reduction has to be used when a delayed reduction or severe impaction resists closed reduction methods. The site of fracture is surgically exposed and the fracture liens are again followed using a chisel. Use of a Rowe or a Hayton Williams forceps can be used after that to complete the last of reduction. After that fixation can be done. In cases of Lefort II and III fracture reduction of fracture is done in the above mentioned ways.

On occasion the superior aspect of the

complex is unstable owing to comminution of adjacent nasal bones, orbital floor and medial orbital wall. The signs of entrapment of the orbital contents are noted and the appropriate wall should be explored to free the entrapment. Fractures should be mobilized and fixation done small defects are connected by placement of a homologues graft. Large defects are treated by an autogenous tip bone graft. 43

If the defect is so large that the bone graft has no shelf on which to set a graft than a Steinmann pin is driven through the infraorbital rim and into the medial and lateral walls forming a base on which to set the graft. Antral packings can be carried out in case of orbital floor fracture via a Caldwell-Luc approach which provides an useful method for treatment of comminuted body rim fracture also. A '/2 inch iodoform gauze preferably run through antibiotic ointment is packed into the antrum and left for 3 weeks and then removed. The sinus is irrigated copiously for another I week and then closed. SAGITTAL MAXILLARY FRACTURES: In reconstruction of the maxillary arch it can be difficult to restore the correct width and projection in sagittal maxillary fractures.

Prior

stabilization of the zygomatic arches creates another outer facial frame and establishes the correct buttress figuration, so that the displaced sagittal fractured maxilla an be put into its proper position. When the mandible is made intact by intermaxillary

immobilization

the

maxillary arch can be positioned anatomically. Atransversal lag screw under the nasal anterior spine, or miniplates horizontally across the sagittal fracture, can be helpful. The palatal fracture can then be exposed and plated.

In the edentulous patients it is important that correct vertical posterior facial height be established so that dentures can be fitted in the future. If possible a gunning split is made from the patient's denture, if not available then a splint made from models cast from dental impression of edentulous jaw should be used. These splints are wired to the upper and lower jaws and then to each other during surgery for a close reduction of fracture in both anterio-posterior and vertical planes. CLASSIFICATION OF METHODS OF MAXILLARY FRACTURE FIXATION: I.

Internal fixation :

Direct osteosynthesis

Miniplates and screws

Wires

Suspension wires

Frontal central or laterally placed (Kufiler)

Circumzygomatic (Cubero)

iii.

Preferred methods of treatment

Zygomatic

iv.

Cirumpalatal/ Palatal screw

Infraorbital

Piriform aperture (Adams)

vii

Peralveolar

II. External Fixation : a)

Cramomandibular

Craniomaxillaly

i) 45

Supra orbital pens

Ancillary methods of treatment

ii)

Zygomatic pins

Less frequently use

iii) Hala frame iv) Levant frame Use of different types of internal wire suspensions. 1.

Frontal

Central - used for Lefort II and III (Mandible is unstable).

Lateral - used for LeFort II and III where mandibular stable.

Circumzygomatic - Lefort II and I

III

Zygomatic - LeFort I

Infraorbital, Pyreform aperture - LeFort I Pyreform Aperture.

Transnasal : Gunning splint

Per-alveolar : Gunning Splint

FIXATION TECHNIQUES : EXTERNAL FIXATION APPLIANCE ON A HEAD CAP : When internal fixation of the maxilla is not possible, external fixation can be applied on a head cap using a Kingsiey splint or Wassmund Hirschgeweih (antlers). Metal side bars, fitted into square tubes on the maxillary splint or maxillary denture, are directed outward through the angle of the mouth and parallel to the buccal surface in the dorsal direction and attached to a plaster head cap by means of elastic bands or rigid plaster connecting bars. The plaster cap can be combined with an extension bar for continuous fraction on the fractured parts by way of rigid or spring supported auxiliary elements. These methods are really only of historical significance.

EXTERNAL FIXATION BY A HALO FRAME : The halo frame is a steel or titanium ring which is screwed to the skull for fixation. The apparatus is constructed on the principle of the head frame used in neurosurgeiy for stereotactic operations.

Traction and

fixation elements can be attached to the ring, which surrounds the entire skull in the manner of a halo. In principle, he halo frame can be used wherever the plastic head cap is appropriate, especially in multiple fractures of the midface. In contrast to the combination of splint side bars, elastics, plaster connecting bars and a head cap, with its many possibilities for fracture and maxillary displacement during healing, the halo frame is safe and more comfortable for the patient. Its advantages are stability and variability. With a halo frame specific regions can be extended without interfering through the mandible and adjustment is easy. The disadvantage is the clumsiness of the apparatus and its marital appearance. However, it is very surprising that patients are not seriously incon\ nienced by this device, and it is more comfortable than a head cap. The halo frame may be fixed to the skull under local anesthesia. For hygienic reasons the hair should be cut as short as possible. In general 4 to 5 screws are used to fix the frame, 2 in the occipital region and 2 or 3 in the anterior part of the skull. The screws placed through the frame must be inserted directly into the bone.

The halo frame is indicated for repositioning the maxilla when no treatment is possible immediately after injury, so that the maxilla is springly fixed after 2 or 3 weelcs and is not mobile enough for surgical replacement and bony fixation.

Using elastic and springs applied on intraoral

splints or transbuccally by ire traction, the maxilla can be slowly repositioned and held in position either for healing or for surgical treatment by intraosseous wiring, suspension wiring or plating. A similar result can be obtained using a Le Vant frame. However, this relies on two supraorbital pins to locate the cranial fixation. Although this is very rigid, it is not always possible to use it in severe craniofacial trauma. These systems can only control the fractures at an occlusal level, and are rarely indicated.

INTERNAL FIXATION BY WIRE SUSPENSION : Internal wiring suspends the maxilla from the mobile part to a fixed point of the non-fractured skull from stable skeletal points into the oral cavity; these are fixed on both sides on the arch bars under traction (craniofacial suspension). The following suspension techniques are common frontomalar suspension, suspension on the glabella, pirifonn aperture wiring, infraorbital wiring, and circumzygomatic wiring. The limitations of wire suspension are the incomplete exposure and the use of compression with suspension wires, which carries the possibility of shortening the midface by compression in cases with multiple fragments.

Suspension wires provide only a single point one 29

dimensional force of application. Three dimensional stabilization is only achieved by multiple fixation points per fragment, or by use of the plate and screw technique. For suspension wiring to be successful there must be effective integrity of the upper jaw buttresses when this is not so suspension wires and IMF will not prevent upward movement of jaw complex along an arc centered at the TMJ leading to open bite anteriorly as well as posterior gagging of occlusion.

Except for circumzygomatic wire suspension, all craniofacial wire suspensions require exposure of the suspension point on the front, on the zygomatic frontal suture, on the infraorbital rim and on the piriform aperture. A hole is drilled at the suspending point nd the wire inserted into it. Both ends of the wire are now fixed in an awl which, with the wire loop, is placed in the oral cavity for frontomalar suspension, suspension of the glabella and infraorbital wiring. Circuimygomatic wiring requires only a loop from the oral cavity circumfe ntial to the zygomatic arch and returning into the oral cavity. Piriform aperture wiring is carried out by exposure of the piriform aperture using a vestibulary incision. The wire ends, brought into the oral cavity, are fixed laterally to the splint either in square tubes or in small wire loops; however, they an also be conducted around the arch bar. Tightening of the wire suspension is done after the occlusion has been established and intermaxillary fixation applied. Suspension wires are normally removed after 6 weeks using an intraoral approach, except or the craniofacial suspension wire at the frontal bone. This must be removed by exposure through a small incision on the wire loop transected here.

OPEN

REDUCTION

AND

INTERNAL

FIXATION

INTEROSSEOUS WIRING : The limitations of internal fixation by wire suspension relate to incomplete fixation of fracture fragments, closed reduction of the lower midface, and compression as a mean of fixation. Closed reduction of ten does not anatomically reconstruct the buttresses of the midface, and three dimensional stability is not obtained.

Midface shortening and

retrusion between the orbits and maxillary alveolus are common complications of internal wire suspension. More accurate restoration of midface height and projection can be achieved by open reduction in the lower maxilla (LeFort I level).

Anteriorly at this level the

nasomaxiUary and zygomaticomaxillary buttresses are stabilized with open reduction. Reconstruction of thin sinus wall fragments between the two anterior pillars is omitted and the pterygoid buttress is not operated upon. The posterior height of the midface is restored by utilizing the ramus height of he mandible combined with intermaxillary fixation. Midface projection is restored in the Le Fort I level by open reduction of the nasomaxillary and the 2ygomatico-maxillary buttresses. In the upper midface open reduction of zygomatic and nasoethmoidal fractures is carried.

In edentulous patients intermaxillary fixation is omitted

following open reduction. Primary bon grafting replaces unusual or absent critical structural supports.

In associated fractures of the mandible it is important to reconstruct the mandible both horizontally and vertically to provide a stable base for intermaxillary fixation and prevent the mandible and maxilla drifting posteriorly and superiorly, thereby producing a disk face. Stabilization of ramus height by open reduction of subcondylar fractures prevents such displacement. Midface fractures managed by extended open reduction sometimes require 2-3 extra weeks of intermaxillary fixation. OPEN

REDUCTION

AND

INTERNAL

FIXATION

MINIMICROPLATES AND SCREWS: The classic treatment of midfacial fractures used to be intermaxillary fixation combined with craniofacial wire suspension or open reduction and external fixation by interosseous wiring, which is unpleasant for the patient who is in many cases affected with multiple traumas. Breathing is difficult, especially when the nose is tamponed and a nasal tube is inserted for feeding. In some cases a tracheotomy is necessary and feeding is only possible with liquids.

Oral hygiene is limited,

especially for sedated patients in intensive care. To prevent these disadvantages early and open surgical management of midface

fractures

has

become

established,

using

miniplates,

microplates and screws. The procedure is based on exact repositioning of the minimum possible number of fragments, and stabilization eventually in combination with bone grafts. In addition to the advantages of exact fragment repositioning, the maxillary height is stabilized and intermaxillary fixation is no longer necessary.

Maxime Champy in 1975 developed the technique used by Francois Michelet in the early 1970s to describe a method of inserting monocortical miniaturized plates on the mandible, and by Harle in 1975 and Luhr in 1979 on the midface. The technical advantages of miniplate osteosynthesis are the use of small and easily adapted plates, monocortical application, functional stability and biomechanical suitability. Indications for use of the miniplate system have been found in orthognathic surgery, in craniofacial surgery, in the treatment of midface fractures, in reconstructive bone surgery, and in preprosthetic and dental implant surgery. The microplate system, a network system using a number of different types and screws, h been developed in different countries. It is well known that today, except for mandibular reconstruction, mini and microplates and screw osteosynthesis are the treatment of choice for craniomaxillofacial bone surgery, but that there are significant differences in design, materials, mechanical properties and cots between the commercially available systems. For this reason they should not be considered interchangeable. The surgeon must decide which system he prefers, and selection should be based on the unit cost, the instruments and implants available, their biocompatability and the compatibility of the implant.

SURGICAL APPROACHES TO EXPOSURE OF THE MAXILLA: INTRAORAL

APPROACH

GINGIVOBUCCAL

SULCUS

(SUBLABIAL) INCISION OR BY MARGINAL RIM INCISION :

The typical intraoral incision lines for exposure of the maxilla are placed within the unattached mucosa 4-5 mm beyond the level of the attached gingiva. In order to reduce scar tissue formation and minimize the risk of infection, the marginal rim incision can be used as an alternative. For the edentulous patient the incision line or exposure of the maxilla is usually on the crest of the alveolar ridge. The lower half of the midface can be exposed using these approaches, as well as the infraorbital rim and the lateral buttress of the maxilla. A common complication of the vestibulary approach is wound dehiscence, which is never seen after a marginal rim incision. The reason for this is the immunological defense mechanism of the periodontium. LOWER EYELID APPROACH:

The lower orbital rim and orbital floor can be exposed transcutaneously through a subciliary, lower eyelid or infraorbital incision.

In the

transconjunctival approach the incision is limited by the fornix. For more extensive exposure a lateral canthotomy and cantolysis is necessary. The lower eyelid incision shows the best results, with a lower complication rate than the other approaches. The incision is placed parallel to the ciliary margin just caudal to the tarsus. The orbicularis muscle is exposed and blunt dissected in the direction of the muscle fibers. The skin muscle flap is turned down and the orbital septum exposed as far as the infraorbital rim.

After this has been

identified an incision is made from the facial side of the rim above the infraorbital nerve through the periosteum.

Using subperiosteal

dissection the orbital floor and the infraorbital rim are exposed above the infraorbital nerve. After osteosynthesis the periosteum is approximated and the skin closed without subcutaneous sutures. TRANSCONJUNCTIVAL LATERAL CANTHOTOMY APPROACH : The transconjunctival lateral canthotomy approach provides wide exposure to the orbital floor, lateral orbital wall, infraorbital rim and lateral orbital rim upto approximately I cm above the frontozygomatic suture. This approach is indicated in addressing fractures in these areas. The complication rate is low ; however, blunting of the lateral canthus and entropion may occur. These problems are eliminated during closure by approximating the cut edge of the tarsal plate to the lateral canthus with a semipermanent suture. The periorbital area is prepared in the usual fashion, with precautions to avoid getting the preparation solution into the eye. A corneal shield may be used at the surgeon's discretion. 60

UPPER LID BLEPHAROPLASTY APPROACH : The upper lid blepharoplasty approach gives excellent access to the frontozygomatic suture, with very good esthetic results, and is becoming more and more popular. The incision is placed in an upper lid skin crease, from midpupil to the lateral orbital rim. As usual in the orbital region homeostasis is performed with bipolar cautery. Monopolar cautery can damage the underlying sclera because of thermal conduction. The incision is continued on the layer of the orbital septum towards the frontozygomatic suture. The periosteum is incised and the fracture is exposed. After bone surgery the periosteum is approximated and the skin incision closed by running, intracutaneous or mattress sutures with no subcutaneous sutures. BROW INCISION: The brow incision for exposure of the frontozygomatic suture is the most common technique, and has an extremely low complication rate. An incision is made through the skin parallel to the hair shafts the superior border of the lateral brow overlying the frontozygomatic suture. The muscle fibers must be blunt dissected down to the periosteum, which is cut and sharply detached.

After the application of osteosynthesis

material the periosteum is approximated subcutaneously and skin sutures placed. After surgery scars are sometimes visible and localized hair loss can occur.

CORONAL APPROACH: 61

The coronal approach gives excellent exposure of the cranium and upper craniofacial skeleton, but widening of the scar on the top of the head, paraesthesias posterior to the incision and weakness of the temporal branch of the facial nerve are documented complications. Shaving the head is not necessary if dural exposure is not intended. The incision is made through the scalp, the subcutaneous tissue and the galea until the loose layer of the scalp between the galea and pericranium is reached. Hemostasis can be obtained with cautery, scalp clips or running silk locking sutures. The dissection in the layer over the pericranium down to the supraorbital rim is relatively bloodless. Care must be taken below the fusion of the temporal lines because of the temporal branch of the facial nerve, which passes over the zygomatic arch 2 cm superior to the supra orbital rim. The pericranium is incised and the dissection continued over the bone to the supraorbital rim. When the neurovascular bundle of the frontal nerve is enclosed in a foramen the bone bridge is excised. To preserve the temporal branch of the facial nerve, the fusion of temporal line and of the superficial and deep layers of the deep temporal fascia must be identified. If the dissection continues superficial to the fascia, the frontal branch of the facial nerve will be transected. Inferior to this line effusion a fit pad is seen which is exposed by an incision in the superficial layer of the deep temporal fascia. The dissection continues through the fat pad, leading to the zygomatic arch.

After incision a subperiosteal detachment on the superior border of the zygomatic arch is performed. The temporal branch of the facial nerve is now retracted laterally with the periosteum of the arch and the superficial layer of the deep temporal fascia. To prevent facial nerve injury sharp instruments should never be used because penetration by a sharp instrument could cause nerve damage. When the nerve has been protected the dissection can proceed in the subperiosteal layer to the lateral orbital rim. If the medial wall must be exposed the anterior and the posterior limbus of the medial canthal ligaments and the lacrimal sac are identified. Caution must be taken to avoid the anterior ethmoidal artery. If dissection must proceed further the artery must be clipped and divided to reduce the chance of an orbital hematoma. If the canthal ligaments require reattachment they should be secured. Also, the temporal fascia should be sutured for proper soft tissue configuration. Wound closure is with either staples or sutures.

POST-OPERATIVE MANAGEMENT:

At the conclusion of the operative period a nasopharyngeal airway is inserted and it is kept patent by occasional aspiration with a length of 3 mm bore polythene tubing attached to a sucker nozzle. If craniomaxillary fixation has been employed, it is possible to defer IMF until the patient has fully recovered consciousness to enable him to breath through the mouth. If IMF a tongue suture brought out of the mouth through the fixation to enable the tongue to be controlled while the patient is unconscious. Suction apparatus, oxygen, tracheostomy set, wire cutters should be available along with emergency drugs by the bed side in case an emergency should occur. Nasopharyngeal airways should be kept in position until the patient should be fully conscious and has an adequate airway and maintains vital signs.

If patient is

cerebrally irritated and restless, IV diazepam is one suitable sedative which may be administered. When patient is conscious and following removal of nasopharyngeal airway respiration may be helped by occasional suction and clearing of blood and mucous from the teeth and coating the lips with petroleum jelly.

Prophylactic antibiotics for

the first week should be mandatory. Adequate fluids by mouth are required. Vital signs to be recorded and maintenance of oral hygiene. In cases necessary a nasogastric tube should be placed. In later postoperative period early ambulation of the patient is desirable and until this is possible the patient should have regular breathing and leg exercises. Fractured are untied in 3 to 4 weeks and fixation can be removed at this time.

COMPLICATIONS

–

Failure to restore anatomic contour leads to septal deviation

–

Malocclusion

–

Infraorbital nerve paresthesia

–

Enophthalmos

–

Infected hardware

–

Altered vision

–

Sinusitis

–

Anosmia

–

Non-union

–

Csf leak

CONCLUSION:

•

Midface fractures occur in a wide variety of patterns

•

The various extended access approaches can be tailored to these fracture patterns

•

Restoration of the facial buttresses is crucial in reestablishing the pretruamatic aesthetic structure and function of the facial skeleton

REFERENCES: Maxillofacial Injuries - Rowe and Williams. Oral and Maxillofacial Trauma - Raymond J.Fonseca. Maxillofacial Surgery - Peter Ward Booth. Killey's fracture of middle third of facial skeleton. Maxillofacial trauma by Robert H.Mathog. Pediatric Maxillofacial Surgery- Kaban Management Of Midfacial Fractures â&#x20AC;&#x201C; Joms (1993)51;960-968 www.sciencedierct.com www.google.com emedicine.com