Submandibular Approach to the Mandible (Cadaver)

The submandibular approach, also known as the Risdon approach, is a well-established extraoral surgical technique employed for the treatment of complex mandibular fractures and pathologies, such as tumors and osteomyelitis.^1,2 Despite the increasing popularity of intraoral approaches for open reduction and internal fixation, the submandibular approach remains a valuable option in the arsenal of maxillofacial surgeons, particularly for challenging fracture patterns such as comminuted, atrophic, and defect fractures.³

This approach offers several advantages, including superior access and visualization of the mandibular body and angle, facilitating better manipulation and reduction of fracture fragments. Additionally, it provides excellent control over the lingual periosteum and inferior border of the mandible.⁴ Furthermore, the submandibular approach enables direct access to the submandibular gland, facilitating its management in cases of pathology or injury. By providing a comprehensive understanding of this technique through cadaveric exploration, this video aims to contribute to the training and education of maxillofacial surgeons, ultimately enhancing patient care and outcomes.

The mandible is the second most commonly fractured facial bone, following the nasal bones. In cases necessitating surgical intervention, mandibular fractures account for a substantial proportion, ranging from approximately 41.6–75.2% of all facial fractures.^5,6 These fractures often result from interpersonal violence, road traffic accidents, falls, and sports-related injuries.⁷ The management of complex mandibular fractures, such as comminuted or atrophic fractures, necessitates careful surgical planning and execution to ensure proper reduction, fixation, and long-term functional and aesthetic outcomes. Furthermore, pathologies involving the mandible and submandibular gland, such as tumors or cysts, may also require surgical intervention through the submandibular approach.

This video provides a detailed account of the submandibular approach to the mandible, based on a cadaver demonstration. It highlights the crucial steps, anatomical considerations, and technical nuances involved in this surgical technique.

The procedure begins with identifying the relevant anatomical landmarks, including the inferior border of the mandible, the angle of the mandible, and the posterior border of the ascending ramus. The incision is made approximately 2 cm below the inferior border of the mandible, typically parallel to the mandibular border or along a natural skin crease, with a length of approximately 5–6 cm.

After incising the skin and subcutaneous tissue down to the platysma muscle, careful dissection is performed to undermine the skin flaps and expose the platysma. The platysma is then incised, allowing access to the superficial layer of the deep cervical fascia. At this stage, the marginal mandibular branch of the facial nerve must be identified and preserved to avoid a potential cosmetic deficit, manifesting as lower lip asymmetry and imbalance.^8,9

The dissection continues through the superficial layer of the deep cervical fascia, exposing the submandibular gland and the associated submandibular lymph nodes. The posterior belly of the digastric muscle may also be visualized during this process.

One of the critical steps in the submandibular approach is the identification and ligation of the facial artery and vein. These vessels can often be palpated and recognized by their pulsatile nature. In cadaveric specimens, however, their identification may be more challenging due to the absence of blood flow.

Once the facial artery and vein are located, typically near the marginal mandibular branch of the facial nerve, they are carefully isolated, ligated, and transected. This step is essential to minimize potential bleeding during the subsequent dissection.

After the facial vessels have been secured, a wide malleable retractor can be placed below the inferior border of the mandible. The periosteum of the pterygomaxillary sling, formed by the masseter muscle laterally and the medial pterygoid muscle medially, is then sharply incised. Care must be taken to avoid excessive lateral dissection into the masseter muscle, as this can lead to significant bleeding.

Subperiosteal dissection is then performed, releasing the masseter muscle laterally and exposing the lateral border of the mandible. This dissection can be facilitated using periosteal elevators of varying sizes, with attention to hemostasis and the avoidance of perforation into the oral cavity through the gingiva.

Once the mandible is fully exposed, the specific pathology or fracture can be appropriately managed, including fracture reduction, fixation with plates or hardware, or resection of pathological lesions. Careful removal of soft tissue down to expose the bone is essential for optimal visualization and hardware placement.

The closure of the surgical site is performed in a layered fashion, beginning with the reapproximation of the pterygomaxillary sling using resorbable sutures. The platysma muscle is then closed with resorbable sutures, typically using a running suture technique.

Subdermal closure is achieved with interrupted sutures, followed by skin closure, which can be performed using non-resorbable sutures or subcuticular absorbable sutures. Meticulous eversion of the skin edges and consistent bite sizes (approximately 2–3 mm from the wound edge) are crucial for optimal aesthetic outcomes.

Postoperative care typically involves the application of antimicrobial ointments, non-adherent dressings, and occlusive dressings, which are typically removed within 24 hours. Suture removal is generally performed around 5 days postoperatively, followed by the application of thin adhesive bandages and liquid medical adhesive for additional wound support.

To summarize, the submandibular approach to the mandible is an essential method in maxillofacial surgery for the treatment of complex mandibular injuries and diseases. Its relevance lies in the access and visualization it affords, enabling precise surgical interventions and optimal outcomes. The cadaveric demonstration and comprehensive description presented in this video serve as an invaluable educational resource, particularly for surgical trainees.¹⁰

Massachusetts General Hospital has given its consent for the cadaver referred to in this video to be used for the education of healthcare professionals and is aware that information will be published online.