Application of Virtual Surgical Planning in Mandibular Segmental Resection With Reconstruction Plate

Introduction:

Odontogenic tumors predominantly affect the mandibular region, constituting approximately 99.1% of all benign tumors in the jawbone. Among these, odontogenic tumors, largely associated with teeth, account for a significant portion. Notably, in the mandibular bone make up 67.7% of all odontogenic tumors in the facial jaw region. Furthermore, benign odontogenic tumors of the mandible often exhibit slow progression, typically devoid of pain, and primarily manifest as bony swelling. As a result, tumors are often detected at later stages, potentially leading to severe complications such as complete mandibular destruction, facial deformities, malocclusion, and, in rare cases, malignant transformation.

The management of benign odontogenic tumors of the mandible remains a subject of debate and challenge. The ideal treatment approach must involve an appropriate level of bone resection while minimizing recurrence, thereby ensuring both aesthetic outcomes and functional restoration in the oral region. Two surgical methods are commonly employed: conservative approaches such as enucleation, curettage, with or without peripheral ostectomy, and radical surgical resection involving segmental bone removal. Segmental mandibular resection is chosen when tumors exhibit extensive bone destruction and do not respond to conservative treatments, particularly in cases of highly invasive tumors with less than 1 cm of remaining bone thickness beneath the lower mandible border.

Although segmental resection achieves high treatment efficacy with a low recurrence rate, it is an invasive approach associated with postoperative anatomical complications. Maintaining the correct alignment of the mandibular condyle within the glenoid fossa after segmental resection is a significant challenge. The natural articulation of the condyle and fossa plays a crucial role in mandibular function. Maintaining the original condylar position after resection remains challenging, leading to issues related to temporomandibular joint (TMJ) function, including joint clicking, pain, and limited mouth opening. Failure to address these issues promptly can result in severe complications such as ankylosis and dislocation, necessitating additional corrective surgery. Therefore, preserving the natural condylar-glenoid fossa relationship is crucial, and it requires special attention. Moreover, accurate alignment of the reconstructed segment with the desired orientation is essential.

With the advent of virtual surgical planning based on 3D modeling and 3D printing technology, tools to aid in the reconstruction of the mandible after segmental resection can be designed and manufactured before surgery, potentially yielding improved postoperative outcomes. The decision to perform immediate reconstruction with bone grafting simultaneously during segmental mandibular resection presents a significant challenge. While this approach may reduce the need for subsequent surgeries and shorten functional recovery time, it remains controversial due to the invasiveness and the strong likelihood of local tumor recurrence. Additionally, this technique may be unsuitable for large tumors or those diagnosed at a late stage. In such cases, grafting becomes challenging, especially when the extent of bone loss in the mandible exceeds 6 cm. Consequently, vascularized bone grafting is an option; however, it is associated with high costs and technical difficulties, limiting its accessibility to many patients. Therefore, segmental mandibular resection combined with reconstruction plate placement remains an effective method for treating benign mandibular odontogenic tumors, reducing the risk of recurrence, and ensuring treatment options for the majority of patients.