Outcomes of Zygomatic Complex Reconstruction With Patient-Specific Titanium Mesh Using Computer-Assisted Techniques

Zygomatic arch reconstruction with a patient-specific polycaprolactone/beta-tricalcium phosphate scaffold after parosteal osteosarcoma resection in a dog

OBJECTIVE

To describe the surgical application of a 3D-printing-based, patient-specific, biocompatible polycaprolactone/beta-tricalcium phosphate (PCL/β-TCP) scaffold to reconstruct the zygomatic arch after tumor resection in a dog.

ANIMAL

A 13 year old female spayed Maltese.

STUDY DESIGN

Case report METHODS: The dog's presenting complaint was swelling ventral to her right eye. A round mass arising from the caudal aspect of the right zygomatic arch was identified by computed tomography (CT). The histopathologic diagnosis was a low-grade spindle-cell tumor. Surgical resection was planned to achieve 5 mm margins. A patient-specific osteotomy guide and polycaprolactone/beta-tricalcium phosphate (PCL/β-TCP) scaffold were produced. Osteotomy, including 30% of total zygomatic arch length, was performed using an oscillating saw aligned with the guide. The scaffold was placed in the defect. Parosteal osteosarcoma was diagnosed based on histopathological examination. Excision was complete, with the closest margin measuring 0.3 mm.

RESULTS

Mild epiphora, due to surgical site swelling, subsided after 20 days. Tissue formation within and around the porous scaffold was noted on CT 10 months postoperatively, with no evidence of metastasis or local recurrence. Facial conformation appeared symmetrical, and no complications were noted 16 months postoperatively.

CONCLUSION

The use of a 3D-printing-based, patient-specific, biocompatible PCL/β-TCP scaffold successfully restored the structure and function of the zygomatic arch without complications, even following wide zygomectomy for complete tumor removal.

3D Printing and Virtual Surgical Planning in Oral and Maxillofacial Surgery

Compared to traditional manufacturing methods, additive manufacturing and 3D printing stand out in their ability to rapidly fabricate complex structures and precise geometries. The growing need for products with different designs, purposes and materials led to the development of 3D printing, serving as a driving force for the 4th industrial revolution and digitization of manufacturing. 3D printing has had a global impact on healthcare, with patient-customized implants now replacing generic implantable medical devices. This revolution has had a particularly significant impact on oral and maxillofacial surgery, where surgeons rely on precision medicine in everyday practice. Trauma, orthognathic surgery and total joint replacement therapy represent several examples of treatments improved by 3D technologies. The widespread and rapid implementation of 3D technologies in clinical settings has led to the development of point-of-care treatment facilities with in-house infrastructure, enabling surgical teams to participate in the 3D design and manufacturing of devices. 3D technologies have had a tremendous impact on clinical outcomes and on the way clinicians approach treatment planning. The current review offers our perspective on the implementation of 3D-based technologies in the field of oral and maxillofacial surgery, while indicating major clinical applications. Moreover, the current report outlines the 3D printing point-of-care concept in the field of oral and maxillofacial surgery.

[Relationship between prognosis and different surgical treatments of zygomatic defects: A retrospective study]

OBJECTIVE

To evaluate the effect and summarize the characteristics of different treatment methods in repairing zygomatic defect.

METHODS

A total of 37 patients with zygomatic defect were reviewed in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from August 2012 to August 2019. According to the anatomical scope of defect, the zygomatic defects were divided into four categories: Class 0, the defect did not involve changes in zygomatic structure or continuity, only deficiency in thickness or projection; Class Ⅰ, defect was located in the zygomatic body or involved only one process; Class Ⅱ, a single defect involved two processes; Class Ⅲa, referred to a single defect involving three processes and above; Class Ⅲb, referred to zygomatic defects associated with large maxillary defects. The etiology, defect time, defect size and characteristics of zygomatic defects, the repair and reconstruction methods, and postoperative complications were collected and analyzed. Postoperative computed tomography (CT) data were collected to evaluate the outcome of zygomatic protrusion. Chromatographic analysis was used to assess the postoperative stability.

RESULTS

Among the causes of defects, 25 cases (67.57%) were caused by trauma, and 11 cases (29.73%) were of surgical defects following tumor resection. We performed autologous bone grafts in 19 cases, 6 cases underwent vascularized tissue flap, 5 cases underwent external implants alone, and 7 cases underwent vascularized tissue flap combined with external implants. After the recovery of the affected side, the average difference of the zygomatic projection between the navigation group and the non-navigation group was 0.45 mm (0.20-2.50 mm) and 1.60 mm (0.10-2.90 mm), with a significant difference (P=0.045). Two patients repaired with titanium mesh combined with anterolateral thigh flap had obvious deformation or fracture of titanium mesh; 2 patients with customized casting prosthesis had infection after surgery and fetched out the prosthesis finally.

CONCLUSION

Autologous free grafts or alloplastic materials may be used in cases without significant structural changes. Pedicle skull flap or vascularized bone tissue flap is recommended for zygomatic bone defects with bone pillar destruction, chronic inflammation, oral and nasal communication or significant soft tissue insufficiency. Titanium mesh can be used to repair a large defect of zygomatic bone, and it is suggested to combine with vascularized bone flap transplantation.

Clinical Application of 3D-Printed Patient-Specific Polycaprolactone/Beta Tricalcium Phosphate Scaffold for Complex Zygomatico-Maxillary Defects

(1) Background: In the present study, we evaluated the efficacy of a 3D-printed, patient-specific polycaprolactone/beta tricalcium phosphate (PCL/β-TCP) scaffold in the treatment of complex zygomatico-maxillary defects. (2) Methods: We evaluated eight patients who underwent immediate or delayed maxillary reconstruction with patient-specific PCL implants between December 2019 and June 2021. The efficacy of these techniques was assessed using the volume and density analysis of computed tomography data obtained before surgery and six months after surgery. (3) Results: Patients underwent maxillary reconstruction with the 3D-printed PCL/β-TCP scaffold based on various reconstructive techniques, including bone graft, fasciocutaneous free flaps, and fat graft. In the volume analysis, satisfactory volume conformity was achieved between the preoperative simulation and actual implant volume with a mean volume conformity of 79.71%, ranging from 70.89% to 86.31%. The ratio of de novo bone formation to total implant volume (bone volume fraction) was satisfactory with a mean bone fraction volume of 23.34%, ranging from 7.81% to 66.21%. Mean tissue density in the region of interest was 188.84 HU, ranging from 151.48 HU to 291.74 HU. (4) Conclusions: The combined use of the PCL/β-TCP scaffold with virtual surgical simulation and 3D printing techniques may replace traditional non-absorbable implants in the future owing to its accuracy and biocompatible properties.

Titanium mesh and pedicled buccal fat pad for the reconstruction of maxillary defect: case report

Background

Pedicled buccal fat pad (PBFP) has been used for the reconstruction of small-sized maxillary defects but cannot be used without hard tissue support on the defect larger than 4 cm × 4 cm × 3 cm.

Case presentation

A 64-year-old man had a history of squamous cell carcinoma of the left maxilla. After removal of the posterior maxilla, a complex bone defect (size, 5 cm × 4 cm × 3 cm) was immediately reconstructed using PBFP combined with a titanium mesh. A pinpoint fistula was found in the left palatal region 1 month after the surgery and was treated with a palatal sliding flap. There were no further complications during the follow-up.

Conclusion

The present technique demonstrated that PBFP combined with a titanium mesh could be used for the reconstruction of complex maxillary defect (size, 5 cm × 4 cm × 3 cm) without additional bone graft.

Three-Dimensional Accuracy of Bone Contouring Surgery for Zygomaticomaxillary Fibrous Dysplasia Using Virtual Planning and Surgical Navigation

PURPOSE

Fibrous dysplasia (FD) is a benign condition in which normal cancellous bone is replaced by immature woven bone and fibrous tissue. The present study aimed to estimate and compare the 3-dimensional (3D) accuracy of bone contouring surgery for zygomaticomaxillary FD performed using virtual planning and surgical navigation versus surgeon's intraoperative assessment.

PATIENTS AND METHODS

This is a retrospective cross-sectional study. Patients with zygomaticomaxillary FD who underwent bone contouring surgery between 2012 and 2019 were reviewed. They were divided into 2 groups: group A underwent bone contouring surgery using virtual planning and surgical navigation, and group B underwent bone contouring surgery by surgeon's intraoperative assessment. The predictor variable was surgical technique. The other variables were gender, age, and operative region. The primary outcome variable was 3D accuracy, which was indicated by root mean square, calculated as a measure of the deviation of the postoperative computed tomography from the preoperative virtual plan. The other outcome variables were patient satisfaction with the outcome by self-evaluation score and operative times. Correlation analysis between the predictor variables and outcome variables was performed.

RESULTS

The sample comprised 24 patients (17 males and 7 females, mean age, 25.7 ± 10.45 years), 13 patients in group A and 11 patients in group B. The mean root mean square was significantly lower in group A than in group B (P = .007). Patient satisfaction with facial symmetry was significantly better in group A (P = .015). Mean operative time was comparable between the 2 groups (P = .918). Surgical technique (P = .011) and operative region (P = .01) were significant influence factors in 3D accuracy of surgery.

CONCLUSIONS

Virtual planning and surgical navigation can significantly improve the 3D accuracy and patient satisfaction of bone contouring surgery for zygomaticomaxillary FD, without prolonging operative time.