2017-18 HSC Section 3 Green Book

H.-T. Liao et al. / Journal of Cranio-Maxillo-Facial Surgery 43 (2015) 1595 e 1601

condylar fractures within the TMJ capsule. The submandibular incision was apt to approach condylar base fractures ( Handschel et al., 2012 ). For a better view and safer identi fi cation of the facial nerve Eckelt and Loukota (2010) recommended a modi fi cation of the submandibular approach: the so-called periangular variant. The retromandibular incision, which is considered to be the gold standard approach, is traditionally used to manage condylar base and neck fractures ( Biglioli and Colletti, 2008; Handschel et al., 2012; Kim et al., 2012; Salgarelli et al., 2013 ). However, the retro- mandibular approach makes it dif fi cult to approach a condylar neck fracture because the retromandibular incision is below the level of Loukota line. Therefore, extreme upward stretching is usually required to expose enough intact cephalic condylar bone for two- hole or three-hole rigid fi xation. This sometimes will cause tran- sient or permanent facial nerve injury due to stretching of the main trunk of facial nerve. Intraoral access using an endoscopic-assisted method, which reduces the risk of facial nerve injury and external scars, offers an alternative approach to subcondylar fractures. However, the technique is dif fi cult and requires expensive equip- ment, a long-term learning curve and more manpower, especially in the treatment of condylar neck fractures ( Kokemueller et al., 2012; Lauer and Schmelzeisen, 1999; Lo and Cheung, 2006 ). Recently, through a better understanding of facial nerve anat- omy, several modi fi cations of the approach found incisions directly at the level of fracture site were the best way to approach and manage the condylar neck fracture ( Choi and Yoo, 1999; Tang et al., 2009; Vesnaver et al., 2005 ). The merits were: facilitation of manipulation to reduce fractures such as medial displacement or medial 90 angulation fractures, and provision of adequate space on both sides for rigid fi xation by direct access to the fracture site. The disadvantage is the complex anatomy of the facial nerve over this area which is thought to increase the risk to the facial nerve. In this study, we described our experiences of a modi fi ed mini- preauricular incision, transparotid approach to manage condylar neck fractures. We also retrospectively compared the complications and functional recovery between the mini-preauricular incision and other approach methods. We believed the modi fi ed approach presented here could achieve the same functional results as other methods. It also would not increase the risk of facial nerve damage and would only leave a 2-cm scar in the preauricular area. From January 2009 to December 2011, 58 patients with condylar fractures who were treated at the department of plastic and reconstructive surgery, Chang Gung Memorial Hospital, Taiwan, were enrolled in the study. The principles outlined in the Decla- ration of Helsinki have been followed in the study. The patient records were retrospectively reviewed for age, sex, injury mecha- nism, fracture pattern, complications, postoperative functional assessment and pre- and post-operative image examination. The inclusion criteria were condylar neck or high subcondylar fracture and management by open reduction and internal fi xation (ORIF). The exclusion criteria were closed treatment of condylar fracture, comminuted condylar fracture and no available image study for preoperative and postoperative analysis. Twenty-nine of 58 pa- tients received a mini-preauricular incision for management of the condylar fracture. The other 29 patients were treated by retro- mandibular incision ( n ¼ 17), an intraoral approach with endoscope-assistance ( n ¼ 13) or a facelift incision ( n ¼ 2) ( Table 1 ). 2.1. Surgical technique 2. Material and methods

solution. An arch bar was fi rst applied to the upper and lower teeth. A 2-cm incision was made over the preauricular area directly on to the fracture site, usually from tragus to ear lobe ( Fig. 1 ). Usually, we fi rst measured the distance of the fracture site from the lower border of ear lobe demonstrated from serial coronal views of 2-dimensional CT ( Fig. 1 ). Then we can mark the midpoint of the incision on the preauricular area as the distance of the fracture site to the lower border of ear-lobe as shown on the images. Then we extend the incision 1-cm from the midpoint superiorly and inferi- orly ( Fig. 1 ). The skin and subcutaneous layer were opened fi rst until the parotid fascia was seen. Then the parotid fascia was opened and blunt dissection was done through the parotid gland using blunt scissors. Attention should be paid once the dissection goes through the interface between the super fi cial and deep parotid gland. A branch of the facial nerve was usually present in this interface. It was better not to see the facial nerve branch when dissecting. If the facial nerve was seen in the interface, careful dissectionwas needed to avoid injuring the branches. After going through the deep pa- rotid gland, the dissection could go directly through the masseter fascia, muscle, and periosteum; fi nally the fracture site of the condylar bone can be seen ( Fig. 2 ). After the fractured condylar segment was dissected and identi fi ed, the fracture could be reduced anatomically and easily by direct visualization, and inter- nally fi xed by miniplates (Leibinger 2.0-mm miniplate system, Stryker, Kalamazoo, MI, USA) or microplates (Leibinger 1.3-mm microplate system) when the acceptable occlusion was achieved by inter-maxillary wiring ( Fig. 3 ). After the open reduction and internal fi xation of a condylar fracture, the inter-maxillary wiring was released to check the motion of the temporomandibular joint and the stability of fracture fi xation. If the function and stability were good, the elastic rubber band was applied to the upper and lower arch bars for guiding the occlusion postoperatively. We advised the patient to take a liquid diet for 2 weeks post- operatively. The elastic rubber band was removed after 2 weeks postoperatively; the patient was encouraged to eat a soft diet for the following 2 weeks and to try and eat a normal diet after this. The coronal view of the CT scan at the fracture site was used to compare either the degree of angulation or displacement of the fracture between the two groups. The angulation is the angle be- tween the axis of condylar fragment and the axis of the mandibular ramus ( Fig. 4 ). The displacement is de fi ned as the overlapping distance between the condylar fragment and the mandibular ramus ( Fig. 4 ). The differences in angulation and displacement between the two groups were also compared postoperatively. The postoperative function outcome was evaluated by occlusion status and maximal mouth opening (MMO). Occlusal relationship was evaluated by both plastic surgeon and orthodontist. Maloc- clusion was divided into three grades: Grade I e the postoperative occlusion is considered acceptable both by the plastic surgeon and the orthodontist, without crossbite or open bite; Grade II e a mild crossbite or open bite was found, but this could be successfully managed by orthodontic treatment; Grade III e a crossbite or open bite was considered signi fi cant and surgical correction was required. Maximal mouth opening was de fi ned as the distance between the upper and lower incisors when the patient opens their mouth as wide as possible. The post-treatment MMO measure- ments were recorded and compared between the two groups. An 2.3. Postoperative jaw function comparison 2.2. Preoperative and postoperative comparison in angulation and displacement of condylar fractures

The patient was put in a supine position under general anaes- thesia. The face, including the ears, was sterilized by beta-iodine

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