(42) Reconstruction of an Atrophic Mandibular Fracture via a Customized, Intraoral Approach: A Novel Technique in the Treatment of Atrophic Mandibular Fractures

Abstract: This study aims to describe the use of virtual surgical planning and a customized reconstruction plate with an inferior guide in the treatment of an atrophic mandibular body fracture via an intraoral approach. The literature reports the use of similar techniques in the reconstruction of atrophic mandibular fractures. However, to the knowledge of the authors, no studies report the application of this modality via an intraoral approach. A 77-year-old female who experienced a mechanical fall presented to the Oral and Maxillofacial Surgery Department at NYU Langone Health Hospital, New York, NY in June 2021. A computed tomography (CT) image revealed a complete fracture through the left mandibular body with associated inferior and lateral displacement of the proximal fracture fragments. The left mandibular body was severely atrophic with a height of approximately 8mm at the fracture site.

Virtual surgical planning was conducted, and anatomic fracture reduction was achieved. An inferior surgical guide was integrated into the customized reconstruction plate to facilitate reduction and keep the inferior alveolar nerve protected during fixation. The patient was taken to surgery under general anesthesia. Intraorally, a vestibular incision was extended from the midline to the left posterior mandible. Dissection was carried through the mentalis muscle and periosteum. The mandible was exposed anteriorly and posteriorly revealing the displaced fracture at the midbody. The left mental nerve was identified and protected. The fracture was reduced and stabilized using a 2.0 locking customized reconstruction plate with an integrated inferior guide according to presurgical planning. While protecting the mental nerve branch, bicortical locking screws and a monocortical locking screw in the proximal segment were used to secure the plate to the mandible below the mandibular canal. The surgical site was irrigated and closed appropriately. A postoperative panoramic image showed adequate reduction of the fracture and plate adaptation. The patient had an uneventful postoperative course. At four months postoperatively, the patient reported complete return of V3 neurosensory function and return to presurgical function with her removable prosthesis.

Several surgical techniques have been described in the treatment of atrophic mandibular fractures. However, due to the lack of adequately sized controlled studies, there is no consensus on treatment in the literature. The repair of these fractures is inherently challenging. It can be difficult to accurately reduce edentulous fracture segments based on anatomic reduction alone. As such, inappropriate contour and malunion are common complications. The use of a custom plate facilitates reproducing the pre-traumatic anatomy, avoids a transcutaneous incision and reduces risk of mental nerve injury associated with adapting the plate while inserting and removing the plate. Furthermore, in an intraoral approach where visualization may be somewhat limited, the inferior surgical guide ensures the hardware is placed at the most favorable anatomic position and potentially decreases intraoperative time.

To date, this is the first description of virtual surgical planning for intraoral management of an atrophic mandible fracture. This case report is encouraging and warrants further studies to validate outcomes.

References:
1. Façanha de Carvalho E, Alkmin Paiva GL, Yonezaki F, Machado GG. Computer-Aided Surgical Simulation in Severe Atrophic Mandibular Fractures: A New Method for Guided Reduction and Temporary Stabilization Before Fixation. J Oral Maxillofac Surg. 2021 Apr;79(4):892.e1-892.e7.
2. Castro-Núñez J, Cunningham LL, Van Sickels JE. Atrophic Mandible Fractures: Are Bone Grafts Necessary? An Update. J Oral Maxillofac Surg. 2017 Nov;75(11):2391-2398.