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Ebook Surgical approaches to the facial skeleton (3/E): Part 2

Part 2 book “Surgical approaches to the facial skeleton” has contents: Submandibular approach, retromandibular approach, rhytidectomy approach, rhytidectomy approach, external (open) approach, endonasal approach. | SECTION 5 Transfacial Approaches to the Mandible 260 The mandible can be exposed by surgical approaches using incisions placed on the skin of the face. The position of the incisions and anatomy vary depending on the region of the mandible that is approached. Because there are almost no anatomic hazards in the transfacial exposure of the mandibular symphysis, this approach is not presented. The focus of this section is on the submandibular, retromandibular, and rhytidectomy approaches. All these are used to expose the posterior regions of the mandible and all must negotiate important anatomic structures. Approaches to the temporomandibular joint are presented in Section 6. 261 9 Submandibular Approach The submandibular approach is one of the most useful approaches to the mandibular ramus and posterior body region, and is occasionally referred to as the Risdon approach. This approach may be used for obtaining access to a myriad of mandibular osteotomies, angle/body fractures, and even condylar fractures and temporomandibular joint (TMJ) ankylosis. Descriptions of the approach differ on some points, but in all the incision is made below the inferior border of the mandible (Video 9.1). Surgical Anatomy Marginal Mandibular Branch of the Facial Nerve After the facial nerve divides into temporofacial and cervicofacial branches, the marginal mandibular branch originates and extends anteriorly and inferiorly within the substance of the parotid gland. The marginal mandibular branch or branches, which supply motor fibers to the facial muscles in the lower lip and chin, represent the most important anatomic hazard while performing the submandibular approach to the mandible. Studies have shown that the nerve passes below the inferior border of the mandible only in very few individuals (see Fig. 9.1). In the Dingman and Grabb classic dissection of 100 facial halves, the marginal mandibular branch was almost 1 cm below the inferior border in 19% of the specimens (1). .