2017-18 HSC Section 3 Green Book

Volume 137, Number 1 • Hybrid Maxillomandibular Fixation System

in 2013. The system consists of the SMARTLock Hybrid MMF Plate (arch bar), which is made of commercially pure titanium. 7 The plate consists of an arch bar segment and nine screw hole seg- ments that project from the arch bars. This plate is secured with monocortical titanium alloy screws placed through the oral mucosa into the support- ing bone in a fashion similar to maxillomandib- ular fixation screws. These screws are 2.0 mm in diameter and come in lengths of 6 and 8 mm. The system also includes a screwdriver, plate cutter, plate bender, and screw spacer. The spacer is used to hold the plate away from the oral mucosa until the screws lock into the plate. The hybrid system is U.S. Food and Drug Administration approved and indicated for temporary stabilization of mandibular and maxillary fractures to maintain proper occlusion in patients with adult dentition (age 12 years and older). 7 Technique All patients had trauma to the maxillofacial regions requiring the use of maxillomandibular fixation and were treated in the Highland Hospi- tal operating room under general anesthesia. The operating surgeons were third- and fourth-year residents at the Department of Oral and Maxillo- facial Surgery. The Stryker SMARTLock arch bars were contoured and cut to fit the maxillary arch. The arch bar was secured using 2 × 6-mm lock- ing screws while the second surgeon elevated the metal rim away from the mucosa with the screw spacer. The screws were placed first in the midline. Once the midline was secured, screws were placed sequentially in a similar fashion from anterior to posterior in each quadrant. The screw holes were bent with the plate bender to orient the screws between the roots of the teeth. The screws were placed at 90-degree angles to the bone. The same procedure was followed to secure the system in the mandibular arch. If needed, the fractured segments were reduced manually to aid in placing the arch bars. The patient was then placed into maxillomandibular fixation using 25-gauge stain- less steel wire. The fractures were then treated as indicated through open or closed techniques as indicated. Patients retained the hybrid system until there was stable occlusion, clinical evidence of healing, andmaximum incisal opening of 40mmor greater. Removal of arch bars was performed in the oral and maxillofacial surgery clinic at Highland Hos- pital. Screw removal was attempted without local anesthesia if there was no mucosal overgrowth of the screws. Local anesthesia was used for areas of

Table 1. Characteristics of an Ideal Maxillomandibular Fixation System Establish occlusion Provide stability Immobilize the jaws

No risk to patient No risk to surgeon Minimize operating room time Minimize orthodontic force

Cost-effective Simple to use Universal application

Corp., Kalamazoo, Mich.) for varying maxillofa- cial operations.

patients and Methods

Study Design This study was a retrospective review of 35 consecutive cases to investigate the strengths and weaknesses of the Stryker SmartLock Hybrid MMF System. The patient population was from High- land Hospital in Oakland, California. The Alam- eda Health System Institutional Review Board approved the study. Subjects Individuals eligible for inclusion were con- secutive patients who had a diagnosis requiring maxillomandibular fixation and had the Stryker SMARTLock system used to establish maxilloman- dibular fixation. All patients were treated by the Department of Maxillofacial Surgery at Highland Hospital, Alameda Health System, Oakland, Cali- fornia, from September of 2013 through February of 2014. Exclusion criteria included age younger than 18 years, no follow-up for arch bar removal, history of radiation therapy to the head and neck region, history of bisphosphonate exposure, lack of postoperative imaging, inability to describe signs and symptoms in English, and any patient in which the SMARTLock device was removed immediately postoperatively. The medical and dental charts including relevant imaging were evaluated to collect patient demographics, comor- bidities, fracture location, arch bar placement time, removal time, sharps exposure, intraopera- tive complications, postoperative complications, and radiographic findings on postoperative cone- beam computed tomographic imaging. Stryker SMARTLOCK Hybrid MMF System The Stryker SMARTLock system is a maxil- lomandibular fixation device that was released

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