2017-18 HSC Section 3 Green Book

The Journal of Craniofacial Surgery • Volume 25, Number 1, January 2014

Hackenberg et al

FIGURE 3. A, Computed tomography showing bilateral displaced fracture of the subcondylar mandible. B, Facial nerve monitoring. C, Blunt dissection of the facial nerve.

reduction during the first surgery with a perpendicular approach to the fracture at no ultimately esthetic cost to the patient. In our ex- perience, risk for permanent paresthesia is not significantly in- creased provided the facial nerve dissection is performed properly under constant monitoring. Endoscopic-Assisted Reduction With Internal Fixation Different techniques have been suggested in the literature re- garding the use of the endoscope for the repair of subcondylar frac- tures. 17,20,37 – 39 Many authors have reached the conclusion that this approach combines the benefits of both closed and open reduction. Documented benefits that have been described and agreed upon are limited scarring and decreased risk to the facial nerve during the sur- gery. Furthermore, the illuminated field grants the surgeon, the assis- tant, the scrub nurse, and the observers a more accessible view. Different authors have used the endoscope either via an extraoral incision placed below the angle of the mandible or via an intraoral incision. 20,40 In our hands, we find introduction of an endo- scope through an intraoral oblique line incision facile. This approach further embraces the hallmark of endoscopic surgery by minimizing scarring because extraoral tissue dissection is limited to the small stab incisions required for the placement of the trochar. It is also noteworthy that the intraoral access forces the sur- geon to approach the fracture in line with the mandibular bone. This

tragus. One problem of the standard preauricular incision is that it hinders access to the mandible by forcing one to approach the frac- ture at a near parallel angle. By placing the incision 8 mm anterior to the tragus, the mandible can be approached at a perpendicular angle, easing plate and screw fixation. Note that shifting the incision anteriorly poses no risk to the facial nerve, which is virtually never found within 8 mm of the tragus. 36 Facial nerve monitoring is used to evaluate facial nerve ac- tivity during the procedure. This aspect is critical in minimizing damage to the facial nerve. After identification of each branch, the facial nerve is carefully separated using blunt dissection (Fig. 3). Displaying the facial nerve in this manner is time consuming but significantly lowers the risk for damage when working between its upper and lower divisions. Reduction of the subcondylar fracture is performed normally. However, in the case of a medial displace- ment, a threaded reduction tool should be readily available in the operating room. This direction of displacement is common because of the insertion of the lateral pterygoid muscle and its action. 6 Wound closure is achieved by closing the parotid fascia separate from the skin. To address esthetic concerns regarding the anteriorly posi- tioned scar, 6 to 12 months postoperatively, the scar can be shifted and repositioned in the direct preauricular position under local anes- thesia. In our experience, the scar is well hidden by this routine, and the low-risk scar revision can be dictated by patient desire. Overall, this approach is beneficial in that it allows for a simpler anatomic

FIGURE 4. A, Radiograph showing large unilateral pneumothorax. Closed reduction with maxillomandibular fixation is relatively contraindicated in this patient. B, Endoscopic setup. C, Intraoperative endoscopic picture of plate fixation. LT, patient's left side.

© 2014 Mutaz B. Habal, MD

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