Facial trauma in children differs from adults. The growing facial skeleton presents several challenges to the reconstructive surgeon. A thorough understanding of the patterns of facial growth and development is needed to form an individualized treatment strategy. A proper diagnosis must be made and treatment options weighed against the risk of causing further harm to facial development. This article focuses on the management of facial fractures in children. Discussed are common fracture patterns based on the development of the facial structure, initial management, diagnostic strategies, new concepts and old controversies regarding radiologic examinations, conservative versus operative intervention, risks of growth impairment, and resorbable fixation.
Key points
- •
The stages of facial growth and development often determine the fracture patterns seen for each age group.
- •
Children are more likely to sustain an intracranial injury in combination with a facial fracture.
- •
Extraocular muscle entrapment is more common in children and may present with a fairly normal-appearing eye.
- •
Most mandibular fractures can be treated with either soft diet or a closed reduction.
- •
Long-term follow-up to assess for growth disturbances is needed.
Introduction
Pediatric facial trauma can be especially disturbing to the family and to the physician faced with the task of reconstruction. The expectation and goal of complete resolution to the premorbid facial structure and appearance can be a daunting task. Fortunately, many advances in the diagnosis and treatment of maxillofacial trauma have helped bring the achievement of this goal closer. Although much of the understanding and experience in regards to maxillofacial trauma comes from the adult population, one must recognize that there are additional concerns in the growing facial skeleton and that the solution for an adult may be entirely different than the solution for a child. Nevertheless, the principles of a comprehensive initial evaluation, a correct diagnosis of the injury, and a patient-based treatment plan remain the same.
Introduction
Pediatric facial trauma can be especially disturbing to the family and to the physician faced with the task of reconstruction. The expectation and goal of complete resolution to the premorbid facial structure and appearance can be a daunting task. Fortunately, many advances in the diagnosis and treatment of maxillofacial trauma have helped bring the achievement of this goal closer. Although much of the understanding and experience in regards to maxillofacial trauma comes from the adult population, one must recognize that there are additional concerns in the growing facial skeleton and that the solution for an adult may be entirely different than the solution for a child. Nevertheless, the principles of a comprehensive initial evaluation, a correct diagnosis of the injury, and a patient-based treatment plan remain the same.
Growth and development
Many of the unique features of pediatric facial trauma are directly related to the underdevelopment and continuing growth of the facial skeleton. Most of the bone of the craniofacial structure is derived from membranous ossification, although there are portions of the skull base and temporomandibular joints that undergo endochondral ossification. The functional matrix concept of growth posits that the growth of the facial skeleton is directed by the overlying muscles acting on the bone. This translates to the theory that scarring and contraction of the soft tissue envelope is responsible for growth disturbances secondary to trauma or surgery.
One of the key factors that relates to the incidence of pediatric facial injuries is the ratio between cranial and facial volume, which is approximately 8:1 starting at birth. This small proportion of the midface in comparison with the cranium is thought to be responsible for the higher incidences of cranial injuries in young children. Brain growth continues to expand the cranium to reach approximately 85% of adult size by the age of 5 years. During the same time period the orbit is growing rapidly and reaches about 90% of its adult size by age 5. However, mid and lower facial growth lag behind considerably. Midfacial growth proceeds in a vertical and anterior direction and nasal growth typically does not reach full adult size until the late teenage years. The mandible reaches its adult width early, by about age 1 year; however, its height is not complete until the teenage years.
The gradual pneumatization of the paranasal sinuses is also thought to contribute to the decreased frequency of facial fractures, because the bone is more solid. The paranasal sinuses grow at different rates. In the newborn period the ethmoid sinuses are present but the remainder of the paranasal sinuses is relatively underdeveloped. The maxillary sinus may begin to develop before 1 year of age, but significant growth may not be seen until 5 years. The frontal sinus is the slowest to pneumatize, starting around 2 years of age, and may not even be identifiable radiologically until around 8 years of age. The frontal sinus continues to grow past puberty to reach full size in young adulthood.
The unerupted teeth in the maxilla and mandible are also thought to contribute to form more dense and stable bone thus increasing the force required to produce a fracture in pediatric patients. Additionally, the prominent buccal fat pads in children are thought to help disperse the force of a blow to the midface region. The bone in this region is also considered more elastic and therefore less likely to completely fracture, but more likely to result in greenstick fracture patterns.
The variations seen in the types of facial injuries that occur between children and adults are related to these variations in the structural anatomy. Initially, children younger than age 2 have much more of the surface anatomy of their craniofacial skeleton centered on the cranium and are therefore more likely to experience more fronto-orbital injuries. As children age and their facial structure begins to grow downward and outward their injury patterns begin to mirror those of adults. Therefore, by the teenage years the patterns of injury are very similar to adult patients.
Epidemiology
Despite advancements in child safety, trauma remains the most common cause of pediatric morbidity and mortality in this country. It has been reported that facial trauma may comprise up to 11% of pediatric emergency department visits. However, most of these visits are related to dentoalveolar and soft tissue injuries. Imahara and colleagues examined 277,008 pediatric trauma patients requiring admission and found facial fractures present in 4.6% of cases. In regard to the total population of maxillofacial fracture patients, children younger than age 17 comprise approximately 14.7% of patients. However, a large number of these patients are teenagers, because the reported incidence of fractures in children younger than the age of 5 years ranges from less than 1% to 5%. It has been reported that the risk of a child with facial trauma to sustain a fracture of the facial skeleton increases by 14% with every year of age.
The cause of pediatric facial fractures also changes with age, but most are related to falls or recreational sports. However, motor vehicle accidents are the most common cause of severe facial fractures or fractures in those children with multisystem injuries. It should also be noted that craniofacial injuries are commonly seen in cases of child maltreatment.
Male gender also increases the likelihood of facial trauma, with boys outnumbering girls almost 2 to 1. It is thought that increased participation in sporting activities or a tendency toward dangerous activities may be responsible for this difference. Interpersonal violence, which is a common cause of maxillofacial fractures in adults, is less common; however, its incidence increases in the teenage population.
The most common site of injury varies according the study population. Because most studies are conducted based on data from trauma databases or from patients seen at trauma centers, many minor, isolated fractures are likely underreported, such as dentoalveolar and nasal bone fractures. Imahara and colleagues examined the National Trauma Data Bank and found the most common pediatric fractures to be mandible (32.7%), nasal bone (30.2%), and maxilla/zygoma (28.6%). Mandible fractures were found more commonly in teenagers. Grunwaldt and colleagues examined the frequency of fractures seen at their emergency room based on age group. In 0 to 5 year olds and in 6 to 11 year olds, orbital fractures were the most commonly seen fractures. However, in 12 to 18 year olds mandible fractures were the most common.
Diagnosis and initial management
The initial evaluation of a child sustaining facial trauma is to confirm and maintain adequate airway, breathing, and circulation, just as in an adult patient. However, a child’s airway is much smaller and therefore can be more prone to airway compromise from swelling or bleeding. Furthermore, children have lower blood volumes and can quickly lose hemodynamic stability.
As with any trauma patient, once the patient is stabilized it is necessary to give priority to diagnosing and addressing life-threatening or high morbidity injuries before focusing on their facial injuries. Because of the previously mentioned small size of the face and its increased bony density, a pediatric facial fracture often indicates high-energy trauma and concomitant injuries to other organ systems must be evaluated. In fact, concomitant injuries have been reported in up to 55% of pediatric facial trauma patients.
Among pediatric trauma service admissions, those with facial fractures have been reported to have almost double the mean Injury Severity Score, and much higher rates of cerebrovascular injuries. In these children, facial fractures were associated with a 63% higher mortality rate. Given the cranial to facial proportions in the growing patient, infants and toddlers have a significantly higher incidence of severe intracranial injuries, and 57% of children younger than 5 years of age with a facial fracture have been found to have a concomitant intracranial injury. In contrast to adults, who may experience cervical spine injuries in around 10% of cases, children are less likely to suffer a concomitant cervical spine injury (0.9%–2.3%). However, concomitant ocular injuries are just as common in children as in adults and because orbital fractures are more frequently seen in children, a thorough ophthalmic examination is crucial. Fifty percent of orbital fractures in children result in ocular injuries and 0.5% to 3% of these may be blinding.
The assessment begins with a thorough history and physical examination. Fear and pain can make this evaluation especially challenging in children. Interviewing the parents or any witnesses to the trauma is likely necessary. The physical examination is commonly compromised by poor cooperation from the child, and therefore, should be approached gently and with as little trauma as possible. Caution is advised in regards to sedated examinations during the primary evaluation. A comprehensive orbital examination is indicated in all patients and should include pupil reactivity and size, visual acuity if possible, assessment for diplopia, and evaluation of extraocular muscle function. Assessment of extraocular movement is even more important in children because of the so-called “white eye” syndrome, in which the eye looks otherwise completely normal except for extraocular movement limitation. Because greenstick fractures are more common in children, orbital floor fractures causing a trapdoor effect and muscle impingement are more likely to be seen in the pediatric population. These patients may also have pain with eye movement, nausea, vomiting, and bradycardia that can mimic the symptoms of a closed head injury. Enophthalmos or hypoglobus should also be noted. The orbital rims can be palpated for bony step-offs but these are often difficult to feel in the pediatric patient. Presence of lateral subconjunctival hemorrhage is a good indicator of an underlying periorbital fracture. A cranial nerve examination can reveal numbness of the V2 or V3 distributions suggesting a fracture. Facial nerve function should also be documented initially because intervention for peripheral or temporal segment injuries may be indicated. Assessing the contour of the zygomatic arch and the symmetry of malar emminences may be difficult because of the increased fat distribution of this region in children. A good nasal examination focusing on symmetry and support of the nasal dorsum and assessing for a septal hematoma should also be part of the initial evaluation. Examination of the oral cavity includes assessing for dental trauma, trismus, malocclusion, and visible step-offs. Remember that the history and physical examination guides the use of further diagnostic testing, not the other way around—this is especially true in the pediatric population.
After suspicion is raised for a fracture a radiologic evaluation is indicated. Although there are many plain film options, these are notoriously unreliable in children because the undeveloped sinuses, unerupted tooth buds, propensity for greenstick fractures, and incompletely ossified areas make identifying fractures difficult. However, panoramic radiography (panorex) continues to be useful in the evaluation of mandibular fractures. Ultimately, computed tomography (CT) remains the gold standard for assessing facial fractures in adult and pediatric patients. Coronal and sagittal formatting of the images allows for improved evaluation of displacement and volume changes around the midface and orbits. CT offers the distinct advantage of providing the operating surgeon with a visible conceptualization of the reconstruction needing to occur in the operating room; this is further aided by three-dimensional reformatting.
Recently there have been significant concerns regarding excess radiation exposure in children. The multiplanar techniques that allow for excellent, detailed images also incur a higher radiation dose. As a result, many institutions have been exploring protocols that lower the dose of radiation with a sacrifice in image quality. This requires a certain balance between the ability to identify subtle greenstick fractures and the need to decrease radiation exposure. Unfortunately, there is insufficient data regarding the diagnostic sensitivity and specificity of these low-dose CT scans in pediatric maxillofacial trauma. However, because many nondisplaced pediatric facial fractures can be treated conservatively, these low-dose CT scans should be considered as a means to diagnose large disruptions in the facial skeleton that require operative intervention. Furthermore, additional postreduction scans are discouraged if the postoperative physical examination is normal. For postoperative evaluation of mandibular injuries, a panoramic radiograph is recommended instead of CT.
Fronto-Orbital Fractures
Because of the increased ratio of cranial vault to the facial skeleton, fractures of the frontal bone and superior orbital rim and roof are more common in children. Thus, these fractures are more common in children younger than 5 years of age when the skull is at its largest. Because the frontal sinus does not start to pneumatize substantially until age 6, these frontal bone fractures are more accurately cranial fractures, which may explain the increased frequency of intracranial injuries in the pediatric population. Without the “crumple zone” of the frontal sinus, forces to the frontal region may result more commonly in fractures of the supraorbital rim and the orbital roof. Because of this differential anatomy, orbital roof fractures are the most common orbital fractures seen in children younger than 10 years of age. Although a fracture of the supraorbital rim can sometimes be palpated on physical examination, diagnosis of an orbital roof fracture can be difficult without CT imaging. However, a depressed fracture of the orbital roof can result in exophthalmos or muscle entrapment limiting extraocular movement. Superior orbital fissure syndrome is also possible in severe fracture patterns. These frontal and orbital roof fractures require a multidisciplinary effort with Neurosurgical and Ophthalmologic involvement. In general, orbital roof fractures rarely require surgical intervention, except for cases with muscle entrapment or when the defect is large-which may lead to orbital pulsations or a late encephalocele. Frontal bone fractures that are displaced more than the full-thickness width of the bone are often repaired to reduce contour deformities. This should be performed in concert with Neurosurgery to evacuate epidural hematomas, repair dural tears, and manage brain injuries. These patients need long-term follow-up because continued brain growth can push apart the fracture site and result in brain herniation that may require cranioplasty in the future.
As children age and the frontal sinus develops, true frontal sinus fractures are more common and are similar to their adult counterparts. However, it has been reported that frontal sinus fractures in children are twice as likely to sustain posterior table injuries and to develop a cerebrospinal fluid leak. The treatment of these injuries is essentially the same as their adult counterparts. Displacement of the posterior table more than the full-thickness width of the bone is a general indication of the possibility for dural injury and mucosal displacement, thus necessitating operative intervention in the form of cranialization. Significant disruption of the nasofrontal duct is another indication for operative intervention. As in adults, there has been a shift away from frontal sinus obliteration and a move toward sinus preservation and delayed endoscopic sinus surgery if necessary. Therefore, follow-up clinic visits and imaging are needed at regular intervals.
Naso-Orbito-Ethmoid Fractures
Naso-orbito-ethmoid (NOE) fractures are often considered the most challenging facial fractures to repair. Fortunately, although reported incidences vary, they are considered relatively rare in children. One of the problems with diagnosing NOE fractures in children is that children already tend to have a low nasal dorsum and an overrotated nasal tip. Therefore, it is necessary to palpate the nasal dorsum to assess whether it is impacted into the midface. This part of the examination can help distinguish between simple nasal bone fractures and NOE fractures needing CT imaging. In addition to a saddle nose deformity, NOE fractures can also result in telecanthus from bony displacement or from medial canthal tendon (MCT) disruption. Disruption at the MCT can be assessed by pulling the eyelids laterally while palpating over the medial canthal region. Normally, the MCT creates an area of tautness (bowstring sign), which may still be present if the MCT is not completely avulsed from the bone. Therefore, bimanual palpation of the medial orbital wall using an intranasal instrument should be performed to test for mobility of the entire complex.
The management of NOE fractures is primarily surgical with open reduction and internal fixation. However, some authors advocate for closed reduction and extraction of the impacted nose if the reduced nasal pyramid feels stable. Open reduction and internal fixation is commonly approached through existing brow lacerations or via a coronal approach. The primary goals are to restore nasal dorsal height and to restore medial canthal attachments and contour. However, bony fragments are often very small and not amenable to screw fixation. Transnasal wiring to stabilize the MCTs or MCT-bearing bone fragments may be necessary, along with cantilevered bone grafts for support at the nasal dorsum. The initial surgery is often the best chance to restore normal positioning, because revision NOE surgery is difficult. The normal narrowing and convexity at the medial canthal region is difficult to re-establish; therefore, external bolsters are recommended to help coapt the overlying soft tissue and splint the underlying bony fragments. Typically these are made from petroleum gauze and secured with transnasal wires or sutures to be left in place for as long as possible (usually 4–6 weeks). Nguyen and colleagues have shown excellent results after long-term bolsters caused ulceration that was allowed to heal secondarily. Stenting of the nasolacrimal system is generally not necessary during the immediate repair, and long-term complaints of epiphora are rare. Ultimately, there are few long-term studies examining outcomes of NOE fracture repairs in children, but the need for revision surgery is common, especially in the growing child.
Orbital Fractures
Orbital fractures are common in children, but treatment strategies remain controversial. It is important to again emphasize that greenstick “trapdoor” fractures with muscle entrapment are more common in children and to be aware of the “white eye” orbital fracture ( Fig. 1 ). In general, after 5 years of age orbital floor fractures become more common than orbital roof fractures. Ophthalmology evaluation is warranted in all cases of pediatric orbital injury. Traumatic optic neuropathy may be discovered, which would warrant aggressive steroid therapy. If visual acuity does not respond or if bony fragments impinge on the optic canal, optic nerve decompression can be considered, although results have been mixed in pediatric trauma patients.
