OPEN ACCESS ATLAS OF OTOLARYNGOLOGY, HEAD & NECK OPERATIVE SURGERY SURGICAL MANAGEMENT OF MAXILLOFACIAL TRAUMA Prabhat Bhama, Mack Cheney Maxillofacial trauma is typically caused by The bony fragments may remain anatomi- blunt trauma due to interpersonal violence, cally reduced or can become displaced moving vehicle accidents (MVA), falls, or depending on the mechanism of injury and sporting activities 1. Because these activi- muscular forces acting on the fragments. ties transcend cultural and geographic The degree of anatomic disruption of frac- borders, maxillofacial trauma remains a tured segments is referred to as displace- global health issue. Technological advan- ment. Blood flow to the fracture site re- ces have resulted in faster methods of sults in callus formation over time follow- transportation and with these developments ed by mineralisation of the callus if the maxillofacial trauma has become a major fracture site is immobilised. public health issue also in the developing world. Although management of the air- Malunion occurs when fracture segments way and cardiopulmonary system take pre- are not reduced and the bone heals in an cedence, facial injuries demand attention anatomically incorrect position 3. In the because of their potential for long-term face, this can cause significant disfigure- impact on quality of life (QOL) and the ment and disability. patient’s psychological wellbeing 2 as the face houses many vital structures neces- Disfigurement occurs because the skin soft sary for sight, hearing, speech, olfaction, tissue envelope (SSTE) of the face is and mastication. dependent upon the underlying maxillo- facial skeletal framework. Anatomic per- turbations of the bony framework from Pathophysiology maxillofacial trauma manifest as abnormal appearances of the SSTE. Depending on When energy transferred to a bone exceeds the location of the fracture(s), the aesthetic its stress tolerance, a fracture may result. deformity may be inconspicuous e.g. mini- Several factors determine if and how a mally displaced anterior maxillary sinus bone fractures: the amount of energy trans- wall fractures, or obvious e.g. displaced ferred to the bone e.g. mechanism of in- nasal bone fractures. jury, speed of collision, airbag deployment etc; vectors of forces; and the charac- Disability occurs when malunion interferes teristics of the tissue involved e.g. anato- with function. This is most evident with mic location of impact and quality/health dentoalveolar or mandibular fractures, as of the bone. malunion can result in dental malocclu- sion, making mastication difficult or im- A simple fracture occurs when a single possible. site of discontinuity exists between two bony segments. With a comminuted frac- The surgeon must ensure that bony frag- ture there are multiple segments of bone. ments are anatomically reduced and stabi- Bone segments protruding through skin are lised so that when healing is complete, considered open fractures, as are fractures callus formation is minimised to minimise of the alveolar bone and sinuses. They are disfigurement and disability. Even when more susceptible to infection compared to reduction is achieved, the result may not be their closed counterparts. Closed fractures ideal. Poor blood supply or wound infec- are uncommon in the face. tion may cause delayed union when bone fails to mineralise 3 months after reduction stantial individual variation is common, and immobilisation. Fibrous union may and premorbid photographs or examination occur (usually within 10 days in adults) if of the unaffected side of the face can be bones are reduced but inadequately immo- beneficial. Intraoperative imaging is also bilised. Non-union may result if bone is used by some to achieve adequate reduc- lost or the wound is contaminated with tion 5, although such technology is costly foreign material. Therefore, the surgeon and time consuming. Bilateral fractures must ensure that a fracture site is clean, may preclude using the contralateral face free of foreign material (insomuch as as a template. In many cases, the surgeon possible), and well vascularised prior to must reference normal anatomic land- reduction and immobilisation. Antibiotics marks. However, when there are no are sometimes warranted to counter bacte- anatomically normal bony landmarks to rial contamination. use as reference, one should first restore dental occlusion, followed by the buttres- Basic Management Principles ses of the face (see section on maxillo- mandibular fixation and anatomy). Not all maxillofacial fractures require intervention. The primary goals of repair Fixation of bone across fracture sites is of craniomaxillofacial (CMF) fractures are done to immobilise the bone against mus- restoration of premorbid anatomy and culoskeletal forces and to permit minerali- function: sation to occur. Fixation is generally ac- complished using titanium plates secured • Craniofacial structure with screws (Figures 1, 2, 3, 4). o Facial height o Facial width o Facial projection • Craniofacial function o Dental occlusion Fracture reduction and fixation are best performed in the 1st two weeks following injury 5. Strict attention to the following principles optimise bone healing and surgi- cal outcomes • Anatomic reduction (realignment) of fracture segments • Fixation (immobilisation) of bones ac- ross fracture sites in the operating room • Postoperative immobilisation of bones across fracture sites (prevention of reinjury or stress to fracture sites) • Preventing infection Figure 1: Plating of pan-facial fractures Anatomic reduction of fractured segments requires a 3-dimensional understanding of maxillofacial anatomy. Nonetheless, sub- 2 Figure 3: Reconstruction (blue) vs. mini- lates (grey) Figure 2: Plain film following ORIF of multiple fractures Screws are either self-tapping or self- Figure 4: Locking (below) vs. non-locking drilling. Self-tapping screws require pre- (above) screws drilling prior to inserting the screws, but also require less force which is advan- Preventing infection begins with initial tageous when fixing fragile bony seg- management in the emergency unit. Open ments. Larger plates and screws provide wounds are copiously irrigated with sterile greater stability and immobilisation. Non- isotonic fluid. Badly contaminated wounds locking plates are typically used for the are thoroughly cleaned and irrigated. Pres- midface. These plates must be shaped to fit surised pulsatile irrigation methods have the bone precisely or they will distract the been demonstrated to be useful in wound bony segment towards the plate when the debridement 6 and are particularly useful to screw is engaged. cleanse wounds with particulate matter e.g. sand and road debris. Prophylactic anti- Locking plates can be helpful when immo- biotics to prevent infection when treating bilising mandibular fractures. When used non-mandibular maxillofacial fractures with locking head screws, locking plates have been discouraged 7, although a recent do not require exact coaptation of the plate review highlighted the lack of large high- to the bone as the bone is not compressed quality randomised controlled trials to eva- against the plate (Figures 3, 4). This luate antibiotic use in non-mandibular avoids impairing cortical bone perfusion facial fractures. When treating fractures of and provides a more stable fixation when the mandible, prophylactic antibiotics are compared to a non-locking system. likely beneficial when used in the imme- diate perioperative period 8. In any case, Because titanium plates and screws are too adherence to sterile technique in the opera- expensive for many developing world cen- ting room and good quality postoperative tres, reliance is placed on stainless steel wound care should not be compromised. wire to reduce and fix fractures. 3 Surgical Anatomy Supraorbial foramen Ant ethm foramen Frontoethmoidal suture Knowing which fractures require treatment Post ethml foramen requires a thorough understanding of the Optic foramen Sup orbital fissure anatomy of the craniomaxillofacial (CMF) Lamina papyracea skeleton and how forces are transmitted Inf. orbital fissure Lacrimal fossa (Figures 5-9). This anatomical knowledge, Infraorbital foramen coupled with a detailed history, physical Inferior turbinate examination, and imaging permit the sur- geon to establish a treatment plan for various fracture patterns. Because of the complexity of the CMF Figure 6: View of orbit skeleton, it is helpful to divide injuries into Frontal bone the following anatomic regions: frontal Supraorbital sinus, nasoethmoid complex (NEC), zygo- foramen Sup orbital fissure maticomaxillary complex (ZMC), midface, Zygomaticofacial foramen palatoalveolar, and mandible. Greater wing of sphenoid Inf orbital fissure Nasal bone Inf orbital foramen Canine fossa Frontal bone Parietal bone Temporal bone Figure 7: Frontal view of the skull Sphenoid bone Zygomatic bone Zygomatic arch Condylar fossa Nasal bone Pterygoid plate Pterygomaxillary fissure Ethmoid bone Maxillary tuberosity Canine fossa Lacrimal bone Maxillary bone Inferior turbinate Figure 8: The internal maxillary artery passes through the pterygomaxillary fis- Figure 5: Frontal view of bones of skull sure to enter the pterygopalatine fossa 4 ry alveolus. The PM buttress extends from Incisive foramen the cranial base superiorly to the inferior border of the pterygoid plates. Transver- Maxilla (palatine process) sely oriented buttresses include the frontal Palatine bone bar, infraorbital rim and nasal bones, and (horizontal