Armamentarium

History of the Procedure

Pediatric facial fractures have been the subject of many retrospective reviews. Most of these express some variation in terms of the demographics of the injuries seen. This is likely a reflection of the setting from which the dataset is drawn (e.g., urban versus suburban trauma centers). Imahara et al queried the National Trauma Data Bank of the American College of Surgeons from 2001 through 2005. This databank comprises inpatient data from more than 600 trauma centers. Over the period examined, 1.5 million patients were entered into the database, and roughly 19% of those were under 18 years of age. Approximately 4.6%, or 12,739, sustained a facial fracture. Motor vehicle accidents were the most common mechanism of injury. In the review, the incidence of fractures increased with the age of the injured patient. The lowest incidence was seen in infants and toddlers and the highest in teens. Also increasing with age was the number of fractures requiring operative intervention. Only 11% of toddlers required surgery, compared with 30% of those aged 15 to 18 years. The most common site of fracture was the mandible (32%). Midfacial injuries were next, with nasal fractures accounting for 30%, followed closely by the zygoma at 28.6%.

Scant instructive literature is available describing the incidence of growth attenuation after a midfacial injury. It would take a large sample size followed over a long period (years) to answer this question definitively, because the effects of an injury and potentially any operative intervention are superimposed on a patient’s premorbid growth pattern. For this reason, case reports and even small case series are of limited value in determining the growth consequences of a midfacial injury. Although the incidence is not known and experimental evidence is conflicting, there are reports of midface hypoplasia resulting after injuries to the midface. Injuries to the nasal and septal regions would seem to have the greatest potential for midface growth attenuation. Aizenbud et al studied a pair of identical twins, one of whom sustained Le Fort II and III fractures at the age of 2 years. The twin who sustained the fractures went on to develop a significant Class III deformity that required surgical correction in late adolescence. This would seem to demonstrate the potential for growth attenuation resulting from nasomaxillary trauma; at the very least, it would suggest that some form of long-term growth observation is warranted in young injured patients. A similar observation in another set of twins, one of whom had minor septal surgery, by Grymer et al, seemed to confirm the importance of the nasal septum in driving maxillary growth.

This chapter focuses on injuries to the midface region in children. Rather than discussing in great detail the management steps of the various fractures encountered in the region, the chapter highlights where these injuries are different in children and the unique considerations involved.

History of the Procedure

Pediatric facial fractures have been the subject of many retrospective reviews. Most of these express some variation in terms of the demographics of the injuries seen. This is likely a reflection of the setting from which the dataset is drawn (e.g., urban versus suburban trauma centers). Imahara et al queried the National Trauma Data Bank of the American College of Surgeons from 2001 through 2005. This databank comprises inpatient data from more than 600 trauma centers. Over the period examined, 1.5 million patients were entered into the database, and roughly 19% of those were under 18 years of age. Approximately 4.6%, or 12,739, sustained a facial fracture. Motor vehicle accidents were the most common mechanism of injury. In the review, the incidence of fractures increased with the age of the injured patient. The lowest incidence was seen in infants and toddlers and the highest in teens. Also increasing with age was the number of fractures requiring operative intervention. Only 11% of toddlers required surgery, compared with 30% of those aged 15 to 18 years. The most common site of fracture was the mandible (32%). Midfacial injuries were next, with nasal fractures accounting for 30%, followed closely by the zygoma at 28.6%.

Scant instructive literature is available describing the incidence of growth attenuation after a midfacial injury. It would take a large sample size followed over a long period (years) to answer this question definitively, because the effects of an injury and potentially any operative intervention are superimposed on a patient’s premorbid growth pattern. For this reason, case reports and even small case series are of limited value in determining the growth consequences of a midfacial injury. Although the incidence is not known and experimental evidence is conflicting, there are reports of midface hypoplasia resulting after injuries to the midface. Injuries to the nasal and septal regions would seem to have the greatest potential for midface growth attenuation. Aizenbud et al studied a pair of identical twins, one of whom sustained Le Fort II and III fractures at the age of 2 years. The twin who sustained the fractures went on to develop a significant Class III deformity that required surgical correction in late adolescence. This would seem to demonstrate the potential for growth attenuation resulting from nasomaxillary trauma; at the very least, it would suggest that some form of long-term growth observation is warranted in young injured patients. A similar observation in another set of twins, one of whom had minor septal surgery, by Grymer et al, seemed to confirm the importance of the nasal septum in driving maxillary growth.

This chapter focuses on injuries to the midface region in children. Rather than discussing in great detail the management steps of the various fractures encountered in the region, the chapter highlights where these injuries are different in children and the unique considerations involved.

Indications for the Use of the Procedure

Midface fractures are rare in children due to several anatomic differences. Craniofacial development proceeds in a cephalocaudal direction. Cranial volume to facial volume ratios at birth are roughly 8 : 1; at the completion of growth, this ratio is 2.5 : 1. As a result, the midface occupies a retruded and therefore protected position. Children also generally have an abundant layer of adipose tissue, a more elastic skeleton, and flexible suture lines. Pediatric fractures, therefore, are more often incomplete and minimally displaced and thus more often require no operative intervention.

The typical fracture patterns seen in the midface of the adult skeleton require the presence of pneumatized paranasal sinuses. These act as weak points between the vertical and horizontal buttresses of the face. Sinus pneumatization begins around 4 years of age and continues through adolescence. For example, a typical zygomaticomaxillary fracture requires the presence of a maxillary sinus. When this is not present, and a fracture occurs, it can be expected to propagate in a more atypical fashion. Orbital floor fractures also require the presence of a maxillary sinus; therefore, orbital roof fractures are more common in early childhood.

The myriad of fixation options available for the adult trauma patient may also be safely applied to the pediatric skeleton, with some unique considerations. Rigid fixation can be safely applied to the craniomaxillofacial skeleton of the child, with due caution to avoid injury to vital structures such as developing tooth buds. The midface in the primary and mixed dentition stages is a crowded place. The sinuses are beginning their pneumatization, and the maxilla is full of tooth buds. In particular, the second molar and canine teeth sit relatively cranial, with only very thin overlying bone, which makes the application of hardware in these regions impossible.

Resorbable fixation has garnered a fair degree of enthusiasm in the management of pediatric facial fractures. The hope with these fixations systems was that the material would reduce the risk of growth attenuation, eliminate the potential for hardware migration into vital structures, and eliminate the need for hardware removal. These devices have gained a level of acceptance; however, in general, compared with titanium fixation systems, they are less rigid, have a thicker profile, and are technically more demanding to place.

Limitations and Contraindications

Technique: Zygomaticomaxillary Complex (ZMC) Fractures

As previously mentioned, the presence of a pneumatized maxillary sinus is required for the typical ZMC fracture to occur. Most ZMC fractures in children are nondisplaced or minimally displaced due to elasticity and the thick covering of adipose tissue. The greater tissue turgor and elasticity of the soft tissue mask in children, compared to adults, are such that a greater degree of fracture displacement is needed to manifest malar flattening. Displacement of the lateral canthus is similar in children and adults.