**4. Advantages**

**Figure 9.** Virtual placement of the pre-manufactured extirpative osteotomy guide on the patient's native mandible and

**Figure 10.** Intraoperative comparison of the virtual surgical planned reconstruction model with the fibular osteomyo‐ cutaneous flap segments secured to the pre-bent reconstruction plate (left). Placement of the plate secured fibula graft

resection /osteotomy guide on the patient's fibula for creation of the neomandible.

724 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

to the native mandible (right).

Heightened aesthetic outcomes and reconstructive accuracy are realized with the multi-stage implementation of virtual surgical planning throughout the four phases of computer-assisted craniomaxillofacial surgery and the use of cutting guides, stereolithographic models and prefabricated plates. In particular, the surgical course with VSP-CAD/CAM implementation, specifically in the oncologic reconstruction of the mandible and maxilla, has been favorably altered when compared to intraoperative planning and in-situ plate bending.[2, 23] More pervasive use of the technology throughout the reconstructive process reduces translational error due to human error.[24] The virtual model data allows manufacturing of cutting guides, plate bending templates, prefabricated reconstruction plates, and also stereolithographic models to facilitate an accurate execution of the virtual plan in the operating room.[11, 13] Preoperative simulation of the maxillo-mandibular relationship facilitates proper alignment of the graft for proper dental occlusion and proper orthognathic relationships.[4, 10] As the majority of the planning of this process has occurred pre-operatively, total operating time is also reduced concordantly.

While achieving reconstructive success was previously reliant on the surgeon's experience and intra-operative trial-and-error using 2-D imaging, VSP-CAD/CAM offers cited benefits over traditional methods which include increased bone-to-bone contact, better dental alignment, improved aesthetic contour, reduced complication rates and decreased intraoperative time. [10, 13] In our review of surgeon-reported benefits, increased reconstruction accuracy in 92% of cases proved to be a major perceived advantage demonstrated by this technology.[24] Furthermore, a future direction of the VSP-CAD/CAM technology includes planning of osseointegrated implants for mandibular reconstruction at the initial virtual planning session to greater improve functional outcomes.[31, 34]

Quantifiable patient satisfaction surveys, subjective outcome evaluations, and clinical assess‐ ment can help to measure functional and aesthetic outcomes.[1, 11, 20, 21, 32, 33, 36] Likely Results from more true-to-plan reconstructions attained by use of this technology, VSP-CAD/ CAM has been purported to translate to increased patient satisfaction. In a 2012 study comparing VSP-CAD/CAM with conventional surgery, patients were asked to report satis‐ faction on a scale of 0-100. Patients who underwent virtually planned surgery reported an average score of 88 compared to an average score of 68 by those patients undergoing traditional reconstruction.[21]

The technical accuracy achieved as a consequence of VSP-CAD/CAM utilization can be enumerated with evaluation of the final reconstruction with the virtual plan via comparison of pre-operative and post-operative three-dimensional CT scans. Performing osteotomy with use of cutting guides has been shown to assist in more accurately designed free flaps, while use of pre-manufactured reconstruction plates versus hand-bent reconstruction plates has been shown to promote true-to-plan reconstructive results.[4],`[9, 2] `Additionally, a noted decreased difference in the overall positioning between the native and reconstructed mandi‐ bles was found in VSP-CAD/CAM aided reconstructions when comparing standard technique reconstructions.[9] Thus, improved reconstructive accuracy via the reduction of human error can be achieved with pre-manufacturing of the reconstructive plates and implementation of VSP-CAD/CAM more pervasively throughout the reconstructive process.[24] It follows that application of VSP-CAD/CAM to refine preoperative planning, intraoperative contouring, and postoperative orthodontic relationships in each surgical step can improve functional and aesthetic outcomes.[22] With completion of the VSP process to the final evaluation phase, 3D comparison imaging not only permits assessment of the reliability of the technology, it allows the collaborative discussion between surgical teams to assess technique and identify areas for improved performance.[25]

error due to human error.[24] The virtual model data allows manufacturing of cutting guides, plate bending templates, prefabricated reconstruction plates, and also stereolithographic models to facilitate an accurate execution of the virtual plan in the operating room.[11, 13] Preoperative simulation of the maxillo-mandibular relationship facilitates proper alignment of the graft for proper dental occlusion and proper orthognathic relationships.[4, 10] As the majority of the planning of this process has occurred pre-operatively, total operating time is

While achieving reconstructive success was previously reliant on the surgeon's experience and intra-operative trial-and-error using 2-D imaging, VSP-CAD/CAM offers cited benefits over traditional methods which include increased bone-to-bone contact, better dental alignment, improved aesthetic contour, reduced complication rates and decreased intraoperative time. [10, 13] In our review of surgeon-reported benefits, increased reconstruction accuracy in 92% of cases proved to be a major perceived advantage demonstrated by this technology.[24] Furthermore, a future direction of the VSP-CAD/CAM technology includes planning of osseointegrated implants for mandibular reconstruction at the initial virtual planning session

Quantifiable patient satisfaction surveys, subjective outcome evaluations, and clinical assess‐ ment can help to measure functional and aesthetic outcomes.[1, 11, 20, 21, 32, 33, 36] Likely Results from more true-to-plan reconstructions attained by use of this technology, VSP-CAD/ CAM has been purported to translate to increased patient satisfaction. In a 2012 study comparing VSP-CAD/CAM with conventional surgery, patients were asked to report satis‐ faction on a scale of 0-100. Patients who underwent virtually planned surgery reported an average score of 88 compared to an average score of 68 by those patients undergoing traditional

The technical accuracy achieved as a consequence of VSP-CAD/CAM utilization can be enumerated with evaluation of the final reconstruction with the virtual plan via comparison of pre-operative and post-operative three-dimensional CT scans. Performing osteotomy with use of cutting guides has been shown to assist in more accurately designed free flaps, while use of pre-manufactured reconstruction plates versus hand-bent reconstruction plates has been shown to promote true-to-plan reconstructive results.[4],`[9, 2] `Additionally, a noted decreased difference in the overall positioning between the native and reconstructed mandi‐ bles was found in VSP-CAD/CAM aided reconstructions when comparing standard technique reconstructions.[9] Thus, improved reconstructive accuracy via the reduction of human error can be achieved with pre-manufacturing of the reconstructive plates and implementation of VSP-CAD/CAM more pervasively throughout the reconstructive process.[24] It follows that application of VSP-CAD/CAM to refine preoperative planning, intraoperative contouring, and postoperative orthodontic relationships in each surgical step can improve functional and aesthetic outcomes.[22] With completion of the VSP process to the final evaluation phase, 3D comparison imaging not only permits assessment of the reliability of the technology, it allows the collaborative discussion between surgical teams to assess technique and identify areas for

also reduced concordantly.

reconstruction.[21]

improved performance.[25]

to greater improve functional outcomes.[31, 34]

726 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

**Figure 12.** Overlay of the virtually planned reconstruction (blue segments) with the native mandible demonstrating translational error using a hand-bent plate (top). Post-operative overlay demonstrating improved match between ac‐ tual and virtual segments using a pre-bent reconstructive plate (bottom).

Pre-operative planning of the resection and reconstructive segmental osteotomies results in enhanced operative time efficiency so that the extent of surgical time required is optimized to precisely execute the previously developed plan.1 Intraoperative surgical planning is thereby converted to a preoperative event so that substantial savings in intraoperative time and reductions in the surgical learning curve may be realized.[1] Such savings may be further realized in reduced surgeon fatigue and concomitant reduced surgical error. Decreased operative time and increased accuracy have been noted in multiple reconstructive series, further illustrating the utility of VSP-CAD/CAM in dealing with complex head and neck reconstruction for various surgical indications.[6, 28, 35] in mandibular reconstructions using fibula free flaps, Hanasono reported a significant decreased mean intraoperative time when utilizing VSP- CAM/CAD.[8] While Seruya et. al did not find a significant decrease in operative time; they described a decrease in mean ischemic time in CAD assisted mandibular recon‐ structions.[29] Reduced ischemia time has been shown to result in decreased flap loss and overall post-operative complications.[27, 29] Enhancing overall intra-operative efficiency is facilitated by the use of pre-manufactured cutting guides and models which enables faster and more accurate osteotomies and graft placement. [7, 31] Use of manufactured pre-bent recon‐ structive plates can also significantly decrease the total operative time; total reconstructive operative time was reported in one case to be less than 90 minutes.[3, 19, 31]

### **5. Disadvantages**

With regard to the current economic climate in healthcare, potential limitation of widespread incorporation of VSP-CAD/CAM technology is its added cost and the resultant financial burdens that may be placed on the patient and medical system.[8, 17, 28, 34] Given the economic healthcare constraints, the improved patient outcomes seen with VSP-CAD/CAM have to be balanced against the cost of the technology.[24, 39] Potential costs are further increased with the use of the manufactured pre-bent reconstruction plates. Given the qualita‐ tive nature of many benefits of VSP-CAD/CAM and the paucity of data currently available, the total value added and cost efficiency of VSP-CAD/CAM utilization has not been formally evaluated and still remains the subject of future studies.[24] As previously discussed, reduc‐ tions in ischemia and/or overall operative time is a potential source of cost reduction. Addi‐ tionally, the decreased complications and patient morbidity, and generalized improved outcomes seen signify cost savings that may offset the technological costs.[24] However, the clinical implications and economic benefits have yet to be formally analyzed with the added cost of VSP-CAD/CAM in the context of various expanding clinical applications including trauma, temporomandibular joint reconstruction, cancer, and skull base surgery.[6, 28, 35, 38] In head and neck cancer reconstruction, patient lifespan, risk for tumor recurrence and disease progression, and quality of life are additional factors that add complexity to the costbenefit evaluation of the technology in an oncologic setting.

#### **6. Summary**

VSP-CAD/CAM is a novel technology that holds potential to consistently and predictably advance reconstructive outcomes, both aesthetically and functionally. This technology is suited for use in spatially complex reconstructive cases due to its ability to visualize and virtually manipulate 3D configurations of the craniomaxillofacial skeleton in a collaborative, synergistic fashion. Its applications are expanding for cases of varying levels of complexity that require precise millimeter precision particularly in trauma, orthognathic procedures and oncology to obtain optimized function and aesthetic outcomes. Implementation of VSP-CAD/ CAM into each stage of the reconstruction affords the opportunity to reduce human transla‐ tional error and facilitates intra-operative decision-making with expedition of the surgical phase.[1, 10, 11, 13, 21, 24] VSP- CAD/CAM technology is attaining acceptance across the multiple surgical disciplines as efforts towards validating its use are increasing, thereby holding promise as an mainstay, innovative solution in the management of challenging head and neck reconstruction cases.
