Why Do Craniofacial Lesions Require Surgical Intervention?
Multiple craniofacial conditions may involve surgical intervention by the maxillofacial surgeon or the neurosurgeon commonly because of the invasive and aggressive nature or life-threatening nature of these group of conditions. Craniofacial tumors often involve a lot of vital structures and in many aggressive cancers, conservative elimination or approach to the tumor is always not a viable option. In such complicated surgical cases that would be challenging both to the maxillofacial surgeon and the oncologist, VSP can be of immense benefit to target the area of craniofacial interest or the part of the craniofacial cavity that has been indicated for surgery. This article explores the different phases involved in the surgical management of craniofacial tumors or other conditions that require surgical intervention through the use of virtual surgical planning.
What Are the Phases Involved in Craniofacial Surgery Using VSP?
Phase 1 or the Modelling Phase:
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In virtual surgical planning, the modeling phase first begins after obtaining the patient's facial or jaw records and accordingly based on the virtual surgical plan, the surgical procedure or the template or guide would be designed for accuracy. Before most surgical procedures, Stereolithographic (a type of 3D printing technology) models are usually obtained or manufactured in the area of the craniomaxillofacial skeleton.
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After these guides are fabricated, the surgeon would eventually opt for specific cutting guides for the cancer surgery or resection. Because of the extensive resection of tumors in most of the craniofacial tumors that extend to the maxilla or the mandible often, the maxillofacial surgeon, the neurosurgeon, or the oncologist usually collaborate in an interdisciplinary management protocol that focuses upon accurate resection of the tumor or cancer margins. This further calls for the need for vascularized bone grafts in these resected areas because of the bony defects or functional deficits created that need to be filled by the surgeon. Vascularized bone grafts are the most common grafts that are indicated usually for oncologic cases that are in most craniofacial tumors or cancers where a bony reconstruction is indicated (example includes using the fibula graft).
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When it comes to the modeling phase in orthognathic procedures, the protocols may be slightly different, yet still, VSP takes on a major role here as well ranging from the pre-bending of plates that need to be screwed or fixated to the precise translation of all the osteotomized ( surgical procedure of cutting or reshaping a bone) segments of the maxilla or mandible.
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In most mandibular advancement procedures that are a part of orthognathic surgery, to avoid all setbacks and for accurate execution of the pre-operative surgical plan as planned by the dental operator or the maxillofacial surgeon, it is interesting indeed to note that virtual surgical planning has revolutionized this field.
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This has in fact led to more post-operative success rates and reduced patient discomfort because of the accuracy in the surgical planning by dental operators or maxillofacial surgeons.
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In most orthognathic procedures or fracture correction, surgeries such as the LeFort I (a surgical procedure used in maxillofacial surgery to correct certain types of dental and facial deformities), bilateral sagittal split osteotomy (performed to correct various types of jaw discrepancies) procedures, etc, the VSP modeling phase in the pre-operative stage or evaluation of the patient is a significant factor that influences success.
Phase 2 or the Surgical Phase:
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Ranging from the use of the surgical template that has been fabricated or from the plate-bending templates or the pre-bending of plates, the surgical fixation step in oral and maxillofacial surgeries can be more easily performed by the operator, in this crucial phase of surgery. Osteotomies are made by the dentist or the surgeon in the mandible or maxilla based upon the fabricated cutting surgical guides. In most cases, maxillomandibular fixation is given the utmost focus and importance in craniofacial conditions.
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In the cases of craniofacial tumors, as elaborated earlier in the modeling phase, after the pre-operative planning, the surgeon now focuses on the resection of the tumors or cancers and the subsequent reconstruction of the oncologic defect. Usually, the harvested osseous flap is cut and osteotomized in situ which is dependent on the surgical cutting guides that were designed earlier by the surgeon in the modeling phase. These flaps are then fixed to the reconstruction plates in the craniofacial cavity before the final prosthetic unit is secured into the bony or the maxillofacial or mandibular defects. The focus of the maxillofacial surgeon or oncologist is on restoring the bony foundation of the craniofacial skeleton. After these surgical steps, the soft tissue reconstruction can then be carried out alongside the surgeon to completely restore esthetics and functionalities to precision. In aggressive craniofacial and jaw cancers, where the patient's stage of metastasis or spread, survival rates, etc are deemed poorer, reconstruction of the craniofacial cavity also is more challenging than ever for the surgeon.
Phase 3 or the Reconstruction Phase:
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In this phase, the modern-day technology of the VSP CAD-CAM (computer-aided design and computer-aided manufacturing) interface is completely utilized by the reconstructive surgeon, taking into consideration all the previous patient-obtained records ranging from the previous operative high-resolution computed tomographic (CT) scan of the craniofacial skeleton, the possible donor sites from the extremities of the body, along with the radiographic CT (computed tomography) or CBCT (cone beam computed tomography) sectional images before surgery.
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Operative 3D CT visualization of the tumor lesion borders for example or the craniofacial margins or target of the surgery can lead to a smooth execution of reconstruction of the defects by the reconstructive team. These multiple benefits of the VSP technology are because of the reduced complications encountered during surgery (that can help avoid recurrence rates of lesions in the patient post-surgery) and also because of reduced chair time or intraoperative time. During this phase, the resection and reconstruction of the craniofacial skeleton that has been virtually planned are well executed by the surgeon through the final placement of the vascularized bone graft in the oncologic site, facilitating proper closure with sutures and by reduction of the fractured bony segments in cases of traumatic craniofacial injuries.
Phase 4 or the Evaluation Phase:
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In this phase, post-operative follow-ups in regular time intervals are indicated for the patients so that post-operative complications can be minimized.
Conclusion
The phases of craniofacial surgery described above can lead to well-executed planning by the interdisciplinary team of the maxillofacial surgeon, the neurosurgeons, and the oncologists. Scope for aesthetic outcomes is possible with the utilization of VSP technology because of its reconstructive accuracy. With the advancement in CAD-CAM technology, surgical template or guide fabrication, with surgical cutting guides designed to eliminate craniofacial tumors or diseases effectively, both functional and esthetic results can be assured in most patients afflicted by craniofacial conditions.
