Frequency and types of fractures in maxillofacial traumas ... · PDF filetwo cases of Le Fort...

$: Frequency and types of fractures in maxillofacial traumas ... · PDF filetwo cases of Le Fort II-III fractures were also observed. Conclusions. ... Multi-slice Computed Tomography$
Head and neck

Review article

ResumenIntroducción. Los traumatismos maxilofaciales (TMF)representan un motivo de consulta común en los ser-vicios de Urgencias. La compleja anatomía del macizofacial requiere de métodos de imágenes multiplanarespara su correcta evaluación.Objetivos. Describir la frecuencia y tipos de fracturasen una serie de pacientes con TMF evaluados median-te tomografía computada multislice (TCMS) conreconstrucciones multiplanares y tridimensionales. Materiales y Métodos. Se revisaron en forma retros-pectiva las tomografías de macizo facial, solicitadaspor TMF a través del servicio de Emergencias duranteel período junio 2008- diciembre 2009. Se recabaron lossiguientes datos: edad, sexo, causa del traumatismo,presencia y tipo de fracturas. Los pacientes fueron eva-luados utilizando un TCMS de 8 filas de detectores. Entodos los casos se realizaron reconstrucciones multi-planares con ventana de alta resolución para hueso ycon ventana para partes blandas, así como reconstruc-ciones tridimensionales.Resultados. Fueron realizadas 137 tomografías porTMF, de las cuales 78 (57%) presentaron 131 fracturas.De estos 78 pacientes, 52 (66%) eran hombres y 26 (34%)mujeres. Edad promedio: 33 años (rango 14-90 años).Causas: 58% accidentes de tránsito; 24% lesiones porenfrentamientos o peleas; 13% lesiones deportivas; y 7%causas varias. Tipo y frecuencia de fracturas: de piso deórbita 18,3%; de senos maxilares 16%; nasales 15,3%; demandíbula 13%; orbitarias 9,2%; del complejo zigomá-tico-malar 12,3%; y dos fracturas Le Fort tipo II-III.Conclusiones. Las fracturas fueron más frecuentes enhombres y en el grupo etario de 15 a 35 años. La mayorcantidad, así como las más complejas, fueran causadaspor accidentes de tránsito; la más común, aislada oasociada a otras, fue la del piso orbitario. Palabras clave. Fracturas maxilofaciales. TCMS.

AbstractFrequency and types of fractures in maxillofacial trau-mas. Assessment using MDCT with multiplanar and3D reconstructions.Introduction. Maxillofacial trauma (MFT) is a commonreason for attendance at Emergency Departments. The com-plex anatomy of the facial bones requires multiplanar imag-ing techniques for a proper evaluation.Objectives. To describe frequency and types of fractures ina series of patients with MFT evaluated by multi-slice com-puted tomography (MDCT) with multiplanar and 3Dreconstructions.Materials and Methods. Facial bone CTs ordered for MFTby the Emergency Department from June 2008 to December2009 were retrospectively reviewed. The following data wereobtained: age, gender, cause of trauma, presence and type offractures. Patients were evaluated with an 8-channelMDCT. Multiplanar reconstructions were performed in allcases using high resolution bone window and soft tissuewindow, as well as 3D reconstructions.Results. One-hundred and thirty-seven CTs were performedfor MFT: 78 (57%) showed 131 fractures. Of these 78 patients,52 (66%) were males and 26 (34%) were females; mean age 33years old (range: 14-90 yrs.). Causes: 58 % were injuries fromtraffic accidents; 24% were injuries from fights; 13% weresport injuries; and 7% were due to miscellaneous etiologies.Type and frequency of fractures: 18.3% were orbital floor frac-tures, 16% were maxillary sinus fractures, 15.3% were nasalfractures, 13% were jaw fractures, 9.2% were orbital fractures,and 12.3% were fractures of the zygomatic-malar complex;two cases of Le Fort II-III fractures were also observed.Conclusions. Fractures were more common in males, in theage range from 15 to 35 years old. Most fractures, and themost complex ones, were caused by traffic accidents. Themost common fracture, either isolated or associated withother fractures, was the orbital floor fracture.Keywords. Maxillofacial fractures. MDCT.

INTRODUCTIÓN

Maxillofacial traumas (MFTs) are an increasinglycommon reason for presenting at EmergencyDepartments. The growing frequency and magnitude

of traffic accidents, as well as the increase in episodesof urban violence, have made these traumas a form ofsocial disease (1). An efficient imaging assessment ofpatients with MFT is essential in the acute stage. Oncepatient compensation has been achieved, to detect

Servicio de Diagnóstico por Imágenes, Sanatorio Parque, Rosario ArgentinaCorrespondencia: Dra. Gabriela Tomich- [email protected]

Recibido: diciembre 2010; aceptado: junio 2011Received: december 2010; accepted: june 2011©SAR-FAARDIT

RAR - Volumen 75 - Número 4 - 2011 Página 1

Frequency and types of fractures in maxillofacial traumas. Assessment usingMulti-slice Computed Tomography withmultiplanar and three-dimensional reconstructions.Gabriela Tomich, Patricio Baigorria, Nicolás Orlando, Mariano Méjico, Cecilia Costamagna, Roberto Villavicencio

Frecuencia 1/12/12 1:17 PM Page 1

Frequency and types of fractures in maxillofacial traumas

fractures and/or soft tissue damage require immedia-te therapy and/or preoperative planning with multi-planar imaging techniques for a proper assessment.

OBJETIVES

To describe the frequency and types of fractures ina series of patients with MFT evaluated by MDCTwith multiplanar and 3D reconstructions.

MATERIALS AND METHODS

One-hundred and thirty-seven facial bone CTsordered for MFT by the Emergency Department fromJune 2008 to December 2009 were retrospectivelyreviewed. The following data were collected: age, gen-der, cause of trauma, presence and type of fractures.

Patients were evaluated with an 8-row multi-sliceCT scanner (GE Brightspeed) by the following proto-col: using a sagittal scout view and bone algorithm sli-ces were programmed from the top of the frontalsinus to the chin, inclusive, with a 1.25-mm thicknessat 1.25-mm intervals. Multiplanar reconstructionswere performed in all cases using high resolutionbone window and soft tissue window, as well as 3Dreconstructions.

Fractures found were classified into the followinggroups: nasal fractures, nasoethmoidal fractures, frac-tures of the zygomatic-malar complex, orbital floorfractures, maxillary sinus wall fractures, frontal sinusfractures, jaw fractures, Le Fort fractures and othersort of fractures.

RESULTS

Of the 137 CTs for MFT reviewed: 78 patients(57%) had 131 fractures. Of these 78 patients, 52 (66%)

were males and 26 (34%) were females. The mean ageof patients with fractures was 33 years old (range: 14-90 yrs.). Sixty-eight percent of patients with fractureswere in the age group between 15 and 35 years old,while only 10% were older than 55. The most commoncauses were injuries determined by traffic accidents(58%); fights (24%) and sport injuries (13%). The typeand frequency of fractures are shown in Table 1.

DISCUSSION

Anatomically, the face is divided into five regions:nasal, orbital, zygomatic, maxillary and mandibular.The nasal region is comprised of the nasal bones, lacri-mal bones, frontal process of the maxilla, nasal septumand ethmoid cells. The orbital region is composed ofseven bones: the maxillary, zygomatic and frontalbones comprise the external orbital skeleton, while theinternal orbit includes the lacrimal, palatine, ethmoidand sphenoid bones. The zygomatic region is comprisedof the zygomatic process of the frontal bone, the zygo-matic bone and the zygomatic process of the maxilla.The maxillary region includes the alveolar process andthe bony components of the hard palate. Finally, themandibular region is composed of the mandible and thetemporomandibular joint, and is notable for being theonly portion of the facial skeleton that is mobile (2).

Functionally, these structures are supported byeight pillars or buttresses, and forces directed towardthe face are distributed along these buttresses. Four ofthese pillars are vertical: the nasomaxillary buttress(connections between the maxilla and nasal bones), thezygomaticomaxillary buttress (from the maxilla to thezygomatic region), the pterygomaxillary buttress (fromthe maxilla to the pterygoid process) and the posterioror mandibular buttress (ascending ramus of the mandi-ble). The four horizontal buttresses include the frontal,zygomatic, maxillary and mandibular buttresses.

The characteristics of fractures resulting from trau-

Página 2 RAR - Volumen 75 - Número 4 - 2011

TYPE OF FRACTURE NUMBER (n) PERCENT (%)

Orbital floor fracture 24 18.3%

Maxillary sinus wall fractures 21 16%

Nasal fractures 20 15.3%

Jaw fractures 17 13%

Fractures of the zygomatic-malar complex 16 12.3%

Orbital wall fractures 12 9.2%

Nasoethmoidal fractures 9 7%

Frontal sinus fractures 5 3.7%

Le Fort fractures 2 1.5

Other fractures 5 3.7

Total 131 100%

Table 1: Frequency and type of fractures in patients with MFT.


Gabriela Tomich et al.

ma are determined by a dynamic factor (given by theforce and energy of the impact) and by a static factor(given by the anatomic characteristics of the boneinvolved). A small impact area results in a localizedfracture, whereas a large impact area leads to moreextensive indirect fractures, because the force is beingtransmitted over a larger area of bone (3).

The most common causes of maxillofacial traumaare traffic accidents, injuries from fights, sport acci-dents or falls. The combination of traffic accidents andinjuries from fights account for 80% of maxillofacialfractures (1).

Facial fractures are classified into central midfacefractures, lateral midface fractures and mandibularfractures. Central midface fractures include: nasal,nasoethmoidal, orbital wall, maxillary sinus and LeFort I and II fractures. Lateral midface fractures inclu-de fractures of the zygomatic-malar complex, zygoma-

tic arch fractures and orbital floor fractures (4), while LeFort III fractures are combined central and lateral mid-face fractures (3). In a series of multi-trauma patientswith over 7,000 facial bone fractures, 24.3% affectedthe mandible and 71.5% affected the central and lateralmidface (3). In our series of patients, the distribution offractures –according to facial regions—can be obser-ved in Graph 1. Almost one third of fractures simulta-neously affected more than one area of the face.

Orbital fractures, because of the complex anatomyof the region, are often associated with maxillary,zygomatic and/or nasal fractures, either in their inter-nal or external region.

Orbital floor fractures were the most common inour series (Fig. 1a), associated in most cases with frac-tures of the maxillary sinus walls. One of the mecha-nisms of this fracture is the blow out, first described byPfeiffer in 1943 (1). This occurs when the force of a directimpact on the eye ball is absorbed by the orbital rim(which remains intact) and is transmitted to the orbitalfloor, which shatters (usually in the middle third, nearthe infraorbital canal). The eyeball usually remainsundamaged. The presence of an air-fluid level or thecomplete occupation of the maxillary sinus is common(Fig. 1b); instead, the presence of orbital emphysema isinfrequent (4). Fat protrudes through the fracture line(sign of the pending drop or tear) (3) (Fig. 1 c).Herniation of inferior rectus muscle and inferior obli-que muscle may also occur and it can be associatedwith diplopia (Fig.1 d). Muscle entrapment and acuteenophthalmos are indications for immediate surgery(4). Less often, fracture segments can herniate upwardinto the orbit, which is called blow-in fracture (4). Whenthere is orbital rim involvement in fractures of the orbi-tal floor, these fractures should be considered separa-


Graph 1: Frequency of fractures according to facial region.

Fig. 1: Orbital wall fractures (a) MDCT coronalreconstruction. Fracture of the right orbital floorwith herniation of orbital fat into the ipsilateralmaxillary sinus (arrow). (b) MDCT coronalreconstruction. Nondisplaced fracture of theright orbital floor with complete occupation ofthe ipsilateral maxillary sinus (asterisk) andsmall bubble of air (arrow). (c) MDCT coronalreconstruction. Fracture of the left orbital floor.Sign of the pending drop or tear: intraorbitalherniation through the fracture line into themaxillary sinus (arrow). (d) MDCT coronalreconstruction. Fracture of the right orbital floorwith involvement of the inferior rectus muscle(asterisk) and loss of soft tissue substance in theright facial region and cheek (arrows).

a b

c d



tely from blow-out fractures, in which, by definition,orbital rims remains intact. Orbital rim involvementhas implications for the surgical therapy technique,and therefore it is important to differentiate both typesof fractures (4). Fractures of the orbital floor are clearlyseen, mainly on coronal reconstructions from MDCTs(Fig. 1 a, b, c, d).

Other orbital fractures had a frequency of appro-ximately 9%, generally associated with fractures of theipsilateral maxillary sinus. The most common orbitalwall fracture is that of the internal wall, which occurs

either as an isolated fracture or in association withother fractures (3, 4). In 50% of cases it is associated withnasal fractures, suggesting a similar causative mecha-nism, and in one-third of cases, it is associated withorbital floor fractures (4). This fracture is more commonin males (5:1) and most injuries involve the left orbit,with the most frequent cause being fist fights (Fig. 2 aand b). It is very frequently associated with orbitalemphysema from ethmoid cells fractures (4) (Fig. 2 c).

Lateral wall fractures (Fig. 2 d) have been reportedto occur at a frequency of approximately 30% in


Fig. 2: Orbital wall fractures (a) MDCT axialslice. Fracture of the internal wall of the leftorbit (arrows) involving anterior and middleethmoidal cells. (b) MDCT axial slice (soft tis-sue window) of the same patient, showinginvolvement of the internal rectus muscle (linearrows) and marked soft tissue swelling in theleft nasoorbital region (arrows). (c) MDCTaxial slice. Fracture of the internal wall of theleft orbit with involvement of the internal rec-tus muscle and small bubble of air at the levelof the fracture line (circle) with occupation ofethmoidal cells (asterisk). (d) MDCT axialslice. Fracture with displacement of the exter-nal wall of the right orbit with small bubble ofair (circle).

a b

a b

Fig. 3: Fracture of the orbital roof (a) MDCTcoronal reconstruction. Fracture of the rightorbital roof (arrow) and bilateral fracture of theorbital floor (arrowheads) in a patient withserious craniofacial trauma. (b) MDCT sagittalreconstruction. Fracture of the orbital roof withdisplacement of bone fragment into the orbit(circle). (c) MDCT sagittal reconstruction sho-wing fracture of the orbital roof (circle in 1)with extension to the apex (arrow in 2).

c

c d



various series (4). Fractures of the orbital roof (Fig. 3 aand b) are rare (occurring at a frequency of 1 to 5%,according to various reports) and the most commoncauses are traffic accidents (5). It is associated withskull base fractures (70%) and frontal sinus fractures(50%) (5). When these fractures are secondary to directimpacts, the supraorbital rim is fractured; instead, ifthe impact force comes through the frontal bone, thethin plate forming the orbital roof is fractured, and thesupraorbital rim remains intact (5). These fractures mayextend to the orbital apex and affect neurological struc-

tures entering the orbit (5) (Fig. 3 c).Nasal fractures are the most common facial fractu-

res, accounting for 50% of isolated fractures of the face(1,4). The nose is the most prominent region of the face,and therefore is frequently affected by traumatic inju-ries (1). The extent of disruption of the nasal bonesdepends on the direction and intensity of the impact.Sixty-six per cent of nasal fractures result from a late-ral force and 13% are the result of a frontal impact (4). Alateral blow to the nose usually causes nasal cartilagedepression or fracture of the ipsilateral nasal bone (Fig.


a b c

d e

f

Fig. 4: Nasal fractures (a) MDCT coronal reconstruction. Fracture with minimal displacement of theleft nasal bone (arrow). (b) MDCT coronal reconstruction. Bilateral fracture with left lateral displa-cement of nasal bones (arrowheads). (c) MDCT axial slices. Comminuted nasal fracture (arrows in1 and 2) with fracture of the nasal septum (circle in 1 and 2) and small air-fluid level in the left maxi-llary sinus (asterisk in 1 and 2) associated with nondisplaced fracture of the anterior wall of the leftmaxillary sinus (arrowhead in 2). (d) MDCT axial slices. Nasal septum hematoma (asterisk in 1)filling the nasal vestibule appearing spontaneously hyperdense (arrows in 2). (e) MDCT coronalreconstruction. Nasal septum hematoma (arrows). (f) MDCT volume rendering (VR) reconstruc-tion. Front view of comminuted nasal fracture.



4 a), while a frontal blow is more commonly associatedwith fractures of both nasal bones (Fig. 4 b) and of thenasal septum (4) (Fig. 4 c). Furthermore, lateral blowsmay damage the nasal cartilage (Fig. 4 d and e). Thisinjury may initially go undetected because of the pre-sence of edema and hemorrhage -which may impairphysical examination—and, if not adequately treated,it may result in deformity and functional impairment(4). Rohrich and Adams (6) have devised a classificationof nasal fractures that is summarized in Table 2.

In our series, isolated nasal fractures account forapproximately 15% of the total, being the third mostfrequent type of fractures after orbital floor fracturesand maxillary sinus fractures. However, probably alarge number of nasal traumas were excluded for nothaving been evaluated by CT. Generally, nasal fractu-res are apparent on clinical examination and radiogra-phic examination is performed to confirm the diagno-sis (CT is performed only upon a maxillofacial surgeo-n’s request) (1) (Fig. 4 f). However, one study demons-trated that 25% of nasal fractures require surgicalreduction, despite a negative plain film examination (7).

Nasoethmoidal fractures (Fig. 5 a and b) occurred ata frequency of 7%. These fractures most often result froma frontal blow over the bridge of the nose, and the nasalpyramid is displaced posteriorly, fracturing the nasalbones, frontal processes of the maxillae, lacrimal bones,ethmoid sinuses, cribriform plate, and nasal septum (4).

They are often clinically associated with hypertelorismand telecanthus, as well as with damage to the lacrimalduct with epiphora (4). In the floor of the anterior cranialfossa, the dura is firmly adhered to the bone; thereforefractures in this region are related to tearing of the durawith cerebrospinal fluid rhinorrhea and the develop-ment of an intracranial pneumocephalus or infection (4).In one series, 70% of these fractures were caused by traf-fic accidents, and in over 50% of patients had associatedsevere nonfacial injuries (4). Nasoethmoidal fractures areclinically classified according to the integrity of the cen-tral bone fragment (Table 3) (8).

Fracture of the zygomatic-malar complex (trima-lar or tripod) is the second most common isolatedfacial fracture (4) and generally result from a direct blowto the lateral midface. The principal lines of fractureinvolve the three processes of the malar bone (orbital,zygomatic and maxillary). (Fig. 6 a) extending fromthe lateral orbital wall, down the postero-lateral wallof the maxillary sinus through the zygomatic arch,separating the zygoma and maxilla (1, 4) (Fig. 6 b and c).Clinical signs and symptoms include cheek depres-sion, infraorbital nerve paresthesia, globe entrapment(when there is orbital floor involvement) decreasedvisual acuity and / or ophthalmoplegia (with orbitalapex involvement) and trismus when fracture of thezygomatic arch compresses the temporalis tendon (4,9,10).The presence of significant displacement of fragments,


TYPES OF FRACTURE CHARACTERISTICS

TYPE I SIMPLE UNILATERAL

TYPE II SIMPLE BILATERAL

TYPE III COMMINUTED UNILATERAL OR BILATERAL

TYPE IV COMPLEX Associated with septal hematoma.

Associated with open nasal laceration.TYPE V COMPLEX Associated with nasoorbitoethmoid fractures

or other facial fractures.

Table 2: Classification of nasal fractures.


I Single fracture of the central bone fragment,no medial canthal tendon involvement.

II Comminuted fracture of the central fragment, no medial canthal tendon involvement.

III Comminuted fracture of the central fragment,with medial canthal tendon involvement.

Table 3: Classification of nasoethmoidal fractures.



trismus, entrapment and / or orbital apex involve-ment are indications for surgery (10). They are classifiedaccording to the direction and magnitude of displace-ment and bony integrity of the zygoma. This classifica-tion was originally described by Kinght and North(10)in 1961, using plain films: type 1 (nondisplaced fractu-res), type 2 (isolated zygomatic arch fracture), type 3(depressed, nondisplaced fractures), type 4 (mediallydisplaced fractures), type 5 (laterally displaced fractu-res) and type 6 (complex or comminuted fractures). Itis now generally accepted that all displaced fracturesrequire open reduction and fixation (11). More recently,a new classification system was devised for these frac-tures (Table 4) (12). In our series, 9.2% of fractures weretrimalar fractures and we also observed 4 isolatedzygomatic arch fractures (Fig. 6 d and e).

Fractures of the maxillary sinus walls were thesecond most common fractures (16%). Except for 2patients who had isolated fractures of the maxillarysinus walls, all other cases were associated with otherfractures involving the central midfacial region.Isolated fractures of the maxillary sinus (Fig. 7 a and b)are uncommon and generally consist in depressedfractures of the anterior wall of the maxillary sinus (1).

Mandibular fractures are classified according tothe anatomic region involved into: symphyseal fractu-res, alveolar process fractures, fractures of the body or

horizontal ramus, fractures of the angle, fractures ofthe ascending ramus, coronoid process fractures andfractures of the mandibular condyle. Their rate ofoccurrence, based on different series, is shown in Table5 (3,13). Condylar fractures are subclassified into intra-capsular and extracapsular. Intracapsular fractures areamenable to medical treatment, while extracapsularfractures require surgical treatment; therefore theirexact localization has important therapeutic implica-tions (3). The most common causes of mandibular frac-tures are traffic accidents and injuries from fights orfalls (13). Knowledge of the mechanism of trauma andthe magnitude and direction of the force involvedhelps to determine the type of injury. The most com-mon signs and symptoms include pain, trismus, diffi-culty chewing, malocclusion, swelling and hematomain the mandibular region. Lost and fractured teethshould be accurately evaluated (13). Any change inocclusion is highly suggestive of mandibular fracture(14). Ecchymosis in the floor of the mouth is a diagnosticsign of a horizontal ramus or symphysis fracture (15).

In our series, mandibular fractures accounted for13% (n=17) of the total: 3 symphyseal / paras-ymphyseal fractures (Fig. 8 a), 4 fractures of the hori-zontal ramus (Fig. 8 b and c), 4 fractures of the ascen-ding ramus (Fig. 8 d and e) and 1 fracture of the angle(Fig. 8 f); all other patients had complex mandibular



A Fracture involving only one of the three processes of the malar bone;zygomatic arch, external orbital rim or infraorbital rim.

B Displaced trimalar fracture

C Comminuted trimalar fracture

Table 4: Classification of fractures of the zygomatic-malar complex.

a b

Fig. 5. Nasoethmoid fractures (a) MDCT axial slice. Bilateral fracture of nasal bones (arrows), fractures of the ethmoid cells (curved arrows), occu-pation of the left sphenoid sinus (asterisk) and fracture of the sphenoid bone (hollow arrow). (b) MDCT axial slice (soft tissue window) of the samepatient, showing fracture of ethmoid cells (white arrow), fracture of the sphenoid bone (black arrow), fracture of the external wall of the left orbit(circle); pneumocephalus is also observed.



fractures with double or triple fracture lines and simul-taneous involvement of the various bone regions.

Bilateral or multiple fractures account for up to50% of mandibular fractures and often respond tocoup-countercoup injuries (13). Common coup-counter-coup patterns include: angle and contralateral body(Fig. 9), bilateral angle, and angle and contralateralcondyle (13). Imaging methods should determine thepresence, number and exact location of fractures, aswell as the dislocation of bone fragments, as such dataare essential for a proper therapeutic management.Isolated mandibular fractures may be evaluated by anorthopanoramic radiograph; however, this method isinadequate to evaluate nondisplaced symphyseal frac-tures or fractures of the posterior region of the mandi-ble and of the condyle, because of structures overlap-ping (3,13). Six of 7 unrecognized mandibular fracturesare located in the posterior region and the most com-mon fracture is of the condyle (13).

It was found that CT scan was 100% sensitive indetecting fractures of the mandible, whereas orthopa-noramic radiograph and conventional x-rays had a sen-sitivity of 86% (13). This is the method of choice to assessmandibular fractures and should be performed in allpatients with suspected mandibular fractures and notonly in selected cases (3,13). MDCT is a valuable tool inthe diagnosis of mandibular fractures, as the integra-tion of axial imaging with multiplanar and 3D recons-tructions reveals the details of the injury anatomy, lea-ding to a correct diagnosis in the vast majority of cases(3,13). Imaging on sagittal plane are very useful in the eva-luation of condylar fractures (13). Three-dimensionalreconstructions are very helpful to plan surgical treat-ment, particularly in cases of fractures with multiplefragments and/or displacement of bone fragments(13,16,17). These results, together with the possibility ofmanipulating perspective in 3D images, reinforce theimportance of its use in the surgical planning and eva-luation of treatment in all mandibular fractures (Fig.10), and especially in condylar fractures (17).

The objectives of treatment are to stabilize and

repair facial anatomy, restore the chewing mechanism,relieve acute symptoms and prevent secondary latecomplications: pseudoarthrosis, mandibular oteomye-litis, ischemic necrosis of the condylar head and pos-ttraumatic injury of the articular disc (3). Magnetic reso-nance imaging (MRI) is the method of choice to detectthese complications (3) and it is also the best imagingtool in the evaluation of the temporomandibular joint,before and after surgical treatment (13).

In 1901, Le Fort published his original work, des-cribing three patterns of facial complex fractures. LeFort outlined three lines of fracture reflecting the rela-tive areas of weakness within the facial skeletal struc-ture. Le Fort’s original description regarded symmetricfractures extending back to and involving the ptery-goid plates.

In Le Fort type I or Guérin’s fracture, the fractureruns transversely with involvement of alveolar zygo-matic arch, the internal walls of both maxillary sinuses,the vomer and the internal pterygoid plates. Thisresults in a separation of the hard palate from the facialbones with dislocation and displacement of the hardpalate (1). This fracture results from a blow deliveredover the upper lip (4).

Le Fort type II fracture (Fig. 11 a, b and c) is alsocalled pyramidal fracture because the central portionof the face becomes separated as a pyramidal frag-ment. The fracture line runs across the nose bridge,through both lacrimal bones, the internal wall andfloor of both orbits, obliquely across the anterior maxi-llary sinus, extending posteriorly to the lower ptery-goid plates (1). It often results from a broad blow overthe central facial region and it is one of the most seve-re central midfacial fractures (4).

Le Fort type III fracture causes the separation ofthe entire facial skeleton from the skull base. The frac-ture line runs bilaterally from the nose bridge to thelacrimal bone, the orbital internal wall and floor to theinferior orbital fissure; at this point, one portion of thefracture line extends across the lateral orbital wall toend near the zygomatico-frontal sutures, while asecond fracture line extends from the orbital floor tothe lower portion of the pterygoid plates. The zygoma-tic arches also are fractured, thereby completing theseparation of the facial skeleton from the skull base (1,4).

The main difference between Le Fort type II and IIIfractures is that the latter include the lateral orbitalwall and zygoma (3). In our series, only 2 patients hadfracture patterns consistent with those describedabove: one Le Fort type II fracture in a 22-year oldmale, caused by a traffic accident and a combined LeFort II/III fracture in a 29-year old male patient who,after loosing consciousness, fell from a height of seve-ral meters. Some Le Fort fractures pearls are as follows:1) all Le Fort fractures involve pterygoid plates; 2) anycombinations of Le Fort I, II and III patterns can occur;and 3) a displaced unilateral Le Fort fracture is possi-ble only with a sagittal and parasagittal hard palatefracture (18).


LOCATION FREQUENCY (*)

Body or horizontal ramus 30 – 40%

Angle 25 – 31%

Condyle 15 – 17%

Symphysis 7 – 15%

Ascending ramus 3 – 9%

Alveolar process 2 – 4%

Coronoid process 1 – 2%

(*) According to different series of the literature reviewed (3,13)

Table 5: Frequency of mandibular fractures accordingto their location.




a b

c

d

e

Fig.6: Fractures of the maxillary zygomatic complex (a) MDCT VR reconstruction, oblique view. Nondisplaced left trimalar fracture (arrows). (b)MDCT coronal reconstruction. Fracture of the right zygomatic- frontal junction (arrow) and fracture of the posterolateral wall of the right maxi-llary sinus (hollow arrow) extending to the floor of the ipsilateral orbit (arrowhead). (c) MDCT axial slice at the level of the orbits, showing frac-ture of the lateral wall of the right orbit (circle above) and a slice at a lower level shows fracture of the right zygomatic arch with two lines (hollowarrows below) and fracture of the right anterior and posterolateral maxillary sinus (arrows below) (d) MDCT axial slice. Isolated fracture withdepressed right zygomatic arch with two fracture lines. (e) MDCT VR reconstruction. Isolated fracture of the right zygomatic arch.

a b

Fig. 7: Fractures of the maxillary sinus (a) MDCT,VR reconstruction. Isolated fracture of the left anterior maxillary sinus with depression. (b)MDCT axial slice. Isolated fracture of the posterior wall of the left maxillary sinus with no displacement (circle) associated with small air-fluid level.

Although not technically part of the facial skeleton,the frontal bone is particularly prominent and ofteninjured in patients with maxillofacial trauma. Thesefractures are the result of either direct trauma or anextension of a skull fracture (4). Sixty-seven percent are

limited to the anterior table, 28% involve both the ante-rior and posterior sinus walls and only 5% are limitedto the posterior sinus table, generally as an extensionof a skull fracture (4). Complex fractures of both theanterior and posterior frontal sinus tables usually are




Fig. 8: Mandibular fractures (a) MDCT axial slices (right) and three-dimensional reconstruction, (left) lower view. Right symphyseal/paras-ymphyseal mandibular fracture involving the alveolar process of the mandible (arrows). (b) MDCT axial slice. Fracture with double line of the lefthorizontal ramus of the mandible (arrows) with soft tissue swelling in the floor of the mouth and narrowed oropharyngeal lumen (asterisk). (c)MDCT VR reconstruction. Fracture of the left horizontal ramus with involvement of the alveolar process and lost tooth (circle). (d) MDCT coro-nal reconstruction. Fracture of the right ascending ramus of the mandible with displacement (arrow). (e) MDCT coronal reconstruction. Fractureof the left ascending ramus at subcondylar location with lateral displacement of the proximal fragment. (f) MDCT sagittal reconstruction.Subcondylar fracture of the ascending ramus of the mandible (arrow). (g) MDCT VR reconstruction, slightly oblique view. Fracture with no dis-placement of the left angle of the mandible.

d e f

a b c

Fig. 9: Mandibular fracture by coup-countercoup injury mechanism:MDCT three-dimensional reconstruction. Double-line fracture of themandible secondary to coup-countercoup injury mechanism: fracture ofthe right angle and of the left horizontal ramus.

Fig. 10: Post-treatment follow-up of mandibular fracture: MDCT VRreconstruction. Postoperative evaluation of double line mandibularfracture treated by osteosynthesis.

associated with other midfacial or skull fractures (4,19).Fractures of the anterior table are the least seriousinjury and often do not require treatment (Fig. 12 a andc). Fractures involving the anterior and posterior tablesare more serious, because they are associated withskull fractures and involvement of the central nervoussystem (19) (Fig. 12 b). Posterior table fractures are oftenassociated with pneumocephalus (Fig. 12 d). The sim-plest classification scheme for frontal sinus fractures

requires a description of both tables and the patency ofthe nasofrontal duct (Table 6) (19). Frontal sinus fractu-res occurred at a frequency of approximately 4% in ourpatients and the most common injury was the isolatedanterior table fracture (only one patient had fracture ofthe anterior and posterior tables associated with orbi-tal and maxillary sinus fractures). We did not observedisolated posterior table fractures. Approximately 10%of patients with frontal sinus fracture experience com-



plications: headache, chronic pain, postoperativeinfections and posttraumatic deformity (20).

Clinically, maxillofacial fracture can be suspectedin a patient with trauma for the presence of certain cli-nical signs, although such signs may be initially conce-aled by overlying edema, hemorrhage and soft tissueswelling (4). Imaging studies are required for fractureconfirmation and characterization.

At present, computed tomography (CT) is the mostwidely accepted method in the evaluation of patientswith maxillofacial trauma, as it makes it possible toidentify and quantify fractures, recognize their trueextent and if there are bone displacements or not, aswell as to assess soft tissue injuries (1,4). MDCT provi-des high-quality imaging in the three planes and exce-llent 3D reconstructions (4). The latter are particularlyuseful to assess bony architecture in large comminu-ted, displaced, and complex fractures involving multi-ple planes (21). Furthermore, they are an excellent com-munication tool with the surgeons, as in the case ofcomplex fractures, they allow an adequate visualiza-tion and easy interpretation of the fracture segmentsand their relationship to one another. This is very help-ful when deciding on the most suitable preoperativeplanning for each patient (4). Essentially, they recreatethe surgeon’s complex mental process of visualizingfractures in preoperative planning (21).

Fox (22) found that 3D imaging was more rapidlyand effectively interpreted by clinicians and surgeonsthan 2D imaging. Reuben et al (23) showed that non-radiologists specialists preferred 3D reconstructions to2D CT images in patients with MFT. Patients incur noadditional risks and experience no overexposure toradiation, as 3D images are obtained by reformattingthe original 2D images (21).

Imaging evaluation of facial injuries cannot be pos-tponed and multi-trauma patients undergoing CT of

the head should be examined for facial injuries at thesame time (1). The speed of MDCT permits CT examina-tion of patients who, would otherwise not tolerate it(such as critical or elderly patients) (1). Early diagnosisand treatment of maxillofacial traumas prevent poten-tial immediate and/or late complications, includingbut not limited to chronic pain, functional deficits andcranial nerve palsy (3).

The role of MRI in the evaluation of MFTs is limi-ted in critical patients because of longer image acquisi-tion times and less definition of cortical bone than CTscans; however, MRI provides valuable informationabout soft tissue injuries, patients with neurologicaldeficits, visual or extraocular muscle impairment, andfractures with a high probability of associated intracra-nial injuries (1).

In our series, other injuries associated with facialfractures included: skull base fractures associated withLe Fort II fracture and temporal bone fracture associa-ted with complex fracture of the ipsilateral orbit.According to various series (1,4,24,25) 1 to 10% of patientswith facial trauma had cervical spine injuries, most ofwhich were asymptomatic. Therefore, routine workupof these patients should include at least one CT of theupper cervical spine (1). In addition, 50% of patientswith MFT have intracranial injuries (24,25). Fractures ofthe upper face are associated with increased likelihoodof lower cervical spine injuries and intracranial inju-ries; unilateral midface injuries are associated withbasilar skull fractures; unilateral mandible injuries areassociated with upper cervical spine injuries, and seve-re facial injuries are associated with severe basilar skullfractures (24). Knowledge of these patterns should leadto extend the examination to the skull and cervicalspine in patients being scanned by CT for MFT, whe-never this is possible depending on the patient’s con-dition and available resources.


a b c

Fig. 11:Le Fort type II fracture (a) MDCT coronal reconstruction. Bilateral fracture of the orbital floor and inferior rim (arrows) associated withfracture of the nasofrontal suture (hollow arrow) and fracture of anterior walls of both maxillary sinuses (arrowheads). (b) MDCT axial slice.Bilateral fracture of anterior and posterolateral walls of maxillary sinuses (circles). Note that both zygomatic processes are intact (arrows). (c)MDCT coronal reconstruction. Bilateral fracture of pterygoid plates (circles).


Fig. 12: Frontal sinus fractures (a) MDCTaxial slices. Above: fracture of the anteriorfrontal sinus table with depression (arrow) andminimum air-fluid level in the left frontalsinus. Below: non-displaced fracture of the leftanterior frontal sinus table (arrow). (b) MDCTaxial slice. Fracture of the anterior and poste-rior frontal sinus tables (arrow) with partialoccupation. (c) MDCT coronal reconstruction.Nondisplaced fracture of the left anterior fron-

tal sinus table (arrows). (d) MDCT axial slice. Fracture of the anterior and posterior frontal sinus tables (circle) with pneumocephalus (arrows).


CONCLUSIONS

In our series, fractures were more common inmales, in the age range from 15 to 35 years old. Mostfractures, and the most complex ones, were caused bytraffic accidents. The most common fracture, either iso-lated or associated with other fractures, was the orbitalfloor fracture. At present, MDCT is the method of choi-ce in the evaluation of maxillofacial traumas, as it doesnot only allow determination of the presence, locationand extent of fractures, but also a simultaneous assess-ment of soft tissues and adequate preoperative plan-ning when necessary. For the latter purpose, 3Dreconstructions are highly valuable, as they allow thesurgeon to have direct and real visualization of fractu-red segments and their relationship to one another.

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TYPE CLINICAL SIGNIFICANCE

Isolated anterior table fracture If displacement is greater than width ofanterior table, requires open reduction

Posterior table fracture By definition, compound skull fracture,requires antibiotic treatmentat a minimum. Consider possible cerebrospinal fluid leak

Nasofrontal duct involvement If involved, requires operative intervention.

Table 6: Frontal bone fractures: clinical significance.

a b c

d



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Frequency and types of fractures in maxillofacial traumas ... · PDF filetwo cases of Le Fort...

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