2017-18 HSC Section 3 Green Book

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

They also used the transmasseteric anteroparotid approach through the nerve-free window to expose the fracture site. Taken together, their key modi fi cations use a longer incision (from pre- auricular to retromandibular) and the approach to the fracture site is via a nerve-free window over the anteroparotid area. However, current concepts of surgery include minimally inva- sive approaches with fewer complications. Biglioli and Colletti re- ported a 2-cm mini-retromandibular transmasseteric approach for condylar fracture ( Biglioli and Colletti, 2008; Colletti et al., 2014 ). The 2-cm incision is far shorter than for other approaches, such as preauricular incisions (58 mm; SD 8 mm), submandibular incisions (55 mm; SD 12 mm) and retromandibular incisions (30 mm; SD 8 mm) ( Handschel et al., 2012 ). They considered all fractures, from high condylar neck to condylar base fractures, that can be managed by the mini-retromandibular approach without facial nerve injury ( Colletti et al., 2014 ). Their modi fi cation uses subcutaneous dissection anteriorly and superiorly which is super fi cial to the su- per fi cial musculoaponeurotic system. Then the anteroparotid margin can be identi fi ed and the fracture site can be approached through the nerve-free window. Our design uses a 2-cm mini-incision over the preauricular re- gion instead of the retromandibular area because the condylar neck fracture level underlies the preauricular region, not the retro- mandibular area. Our mini-preauricular approach is directly onto the fracture site with less need for traction during fracture reduc- tion and fi xation. Another difference is that we use a transparotid approach instead of an anteroparotid approach. During dissection via an anteroparotid approach, the facial nerve was reported as seen in 50% of cases; in contrast, we rarely see the facial nerve via the transparotid approach. We believe that the parotid gland can protect the buried facial nerve branch during traction. Conversely, facial nerve injury will increase if a bare nerve is stretched without soft tissue protection during traction. There were no parotid gland complications such as salivary fi stulae or sialoceles were in our series. Most surgeons may query whether facial nerve damage will increase when using a small incision which is directly over the complex network of the facial nerve. In our study, there is no sig- ni fi cant increase in the incidence of facial nerve injury for the mini- preauricular incision compared with other approaches. The limited facial nerve injury is attributed to a precise knowledge of the dis- tribution of the facial nerve and careful dissection during operation. The facial nerve has usually already divided into fi ve major branches in front of condylar region. Therefore, there is some nerve-sparing space between the major branches which is safe to use for approaching the condylar fracture. During dissection, it is quite safe to use a knife or cautery before the sheath of parotid gland is opened. For dissection through the parotid gland, it is better to use blunt scissors for blunt dissection instead of cautery, sharp scissors or knives. Remember that the facial nerve always lies on the interface between the super fi cial and deep parotid gland. The primary goal is to dissect a tunnel through the nerve-sparing space between the major branches of facial nerve, usually be- tween the zygomatic and buccal branches or the buccal and mar- ginal mandibular branches. The dissection will be safe if no major branch is seen during dissection. If a major branch is seen during dissection, you should be careful not to skeletonize the nerve from the soft tissue because it will increase the incidence of nerve injury. Instead, you should preserve the soft tissue surrounding the nerve and change the dissection route going either above or below the exposed major branch. Once the dissection is through the parotid gland and the fascia of the masseter muscle is seen, then you can use the scissors and elevator to open the muscle and periosteum to exposure the fracture site. Because the tunnel is usually level with the fracture site, the heavy traction that is required when using the

retromandibular approach during reduction and fi xation of the fracture is usually avoided. Using this precise method of dissection, we report no transient or permanent facial nerve injury for mini- preauricular incisions. Although we report low complications for facial nerve injury via the mini-preauricular incision with trans- parotid approach, we consider this approach may not be suitable for inexperienced TMJ surgeons. We suggest that less-experienced surgeons begin with a wider incision, such as Choi's, Tang's or Salgarelli's modi fi cation, for better understanding and visualization of the safe zone between facial nerve branches. Another issue to be addressed is whether stable osteosynthesis could be achieved via the mini-preauricular incision compared with other approaches. The position paper from the 2nd Interna- tional Bone Research Association (IBRA) Symposium for Condylar Fracture Osteosynthesis 2012, considered if 3D-plates (such as a TCP plate) or two straight miniplates could achieve more stable condylar neck fracture repair than a single miniplate ( Neff et al., 2014a ). Choi et al. also found that the double miniplate fi xation technique functionally provides more stable fi xation for fractures of the condylar neck than a single miniplate or a minidynamic compression plate ( Al-Kayat and Bramley, 1979; Choi et al., 2001 ). Indeed, in our series we found that for mild angulation cases in both groups a single miniplate was used. However, the mini- preauricular incision (37.9%) did not impede the use of a stable double miniplate fi xation system compared with the other ap- proaches group (31%) ( Table 1 ). The mini-preauricular incision with transparotid dissection can be considered to be a relatively safe and effective method to approach condylar neck fractures. It could be an alternative approach for the experienced surgeon. The complication rate, hospital stay and functional results are no worse than for the ret- romandibular or endoscopic-assisted method. Instead, it provides the advantages of a short scar and ease of reduction and fi xation of the fracture because the approach is directly over the fracture site. The successful approach to the fracture site without facial nerve injury is based on a clear understanding of facial nerve anatomy and careful dissection. Con fl ict of interest statement There is no fi nancial disclosure and con fl icts of interest required for all authors. 5. Conclusion

Acknowledgement

There is no funding for the research.

References

Al-Kayat A, Bramley P: A modi fi ed pre-auricular approach to the temporoman- dibular joint and malar arch. Br J Oral Surg 17: 91 e 103 , 1979 Biglioli F, Colletti G: Mini-retromandibular approach to condylar fractures. J Craniomaxillofac Surg 36: 378 e 383 , 2008 Choi BH, Yoo JH: Open reduction of condylar neck fractures with exposure of the facial nerve. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 88: 292 e 296 , 1999 Choi BH, Yi CK, Yoo JH: Clinical evaluation of 3 types of plate osteosynthesis for fi xation of condylar neck fractures. J Oral Maxillofac Surg 59: 734 e 737 , 2001 discussion 738 Colletti G, Battista VM, Allevi F, Giovanditto F, Rabbiosi D, Biglioli F: Extraoral approach to mandibular condylar fractures: our experience with 100 cases. J Craniomaxillofac Surg 42: e186 e 194 , 2014 Delaire J, Le Roux J, Tulasne JF: Functional treatment of fractures of the mandibular condyle and its neck. Rev Stomatol Chir Maxillofac 76: 331 e 350 , 1975 do Egito Vasconcelos BC, Bessa-Nogueira RV, da Silva LC: Prospective study of facial nerve function after surgical procedures for the treatment of temporoman- dibular pathology. J Oral Maxillofac Surg 65: 972 e 978 , 2007

26