Osseointegrated Implants and Prosthetic Reconstruction Following Skull Base Surgery

Polymers in 3D printing of external maxillofacial prostheses and in their retention systems

Maxillofacial defects, arising from trauma, oncological disease or congenital abnormalities, detrimentally affect daily life. Prosthetic repair offers the aesthetic and functional reconstruction with the help of materials mimicking natural tissues. 3D polymer printing enables the design of patient-specific prostheses with high structural complexity, as well as rapid and low-cost fabrication on-demand. However, 3D printing for prosthetics is still in the early stage of development and faces various challenges for widespread use. This is because the most suitable polymers for maxillofacial restoration are soft materials that do not have the required printability, mechanical strength of the printed parts, as well as functionality. This review focuses on the challenges and opportunities of 3D printing techniques for production of polymer maxillofacial prostheses using computer-aided design and modeling software. Review discusses the widely used polymers, as well as their blends and composites, which meet the most important assessment criteria, such as the physicochemical, biological, aesthetic properties and processability in 3D printing. In addition, strategies for improving the polymer properties, such as their printability, mechanical strength, and their ability to print multimaterial and architectural structures are highlighted. The current state of the prosthetic retention system is presented with a focus on actively used polymer adhesives and the recently implemented prosthesis-supporting osseointegrated implants, with an emphasis on their creation from 3D-printed polymers. The successful prosthetics is discussed in terms of the specificity of polymer materials at the restoration site. The approaches and technological prospects are also explored through the examples of the nasal, auricle and ocular prostheses, ranging from prototypes to end-use products.

Surgical Management of Complex Skull Base Tumor Using Preoperative Multimodal Image Fusion Technology

OBJECTIVE

To review our single-institution experience in the surgical management of complex skull base tumors using multimodal image fusion technology.

METHODS

From October 2019 to January 2022, 7 cases of complex skull base tumors that performed preoperative multimodal image fusion in Zhuhai People's Hospital neurosurgery department were involved in this study. The image data were uploaded to the GE AW workstation. Corresponding image sequences were opened in the workstation to complete registration fusion and 3D reconstruction. We retrospectively reviewed the clinical and imaging data, and surgical strategy, respectively.

RESULTS

one case of recurrent C2 schwannoma, 1 case of recurrent spindle cell tumor of the left cranio-orbital communication, 1 case of lobular malignant tumor of the left infratemporal fossa, 1 case of central giant cell repairing granuloma, 1 case of mesenchymal malignant tumor in left pharyngeal process, 1 case of meningioma in jugular foramen, and 1 case of hemangioblastoma with vascular malformation in fourth ventricular. All cases underwent preoperative multimodal image fusion for the surgical plan and all cases had gross total resection. Except for one case of mesenchymal malignant tumor in left pharyngeal process that had dysphagia and one case of hemangioblastoma that had discoordination, others cases were without postoperative complication.

CONCLUSIONS

Preoperative multimodal image fusion and surgical approach simulation benefit complex skull base tumor surgical treatment. Individually multiple image assessment of complex skull base tumors to determine the specific surgical strategy is more rational and should be recommended (Supplemental Digital Content 1, Supplementary Video, http://links.lww.com/SCS/F936).

State of the Art Care in Computer-Assisted Facial Prosthetic Rehabilitation

ABSTRACT

Autologous reconstruction for major facial defects is primarily considered for patient's lifetime care. There are situations, however, when autologous reconstruction is not ideal or feasible, and prosthetic reconstruction is necessary to reconstruct missing anatomy or to complement surgical reconstruction. The history of facial prosthetic reconstruction can be traced for millennia. At our craniofacial center, craniomaxillofacial prosthetic rehabilitation has been incorporated in the care provided to our patients since the center's inception, more than 70 years ago.The purpose of this review is to present the evolution of our current thinking based on our long experience since the implementation of computer-assistive technologies over 15 years ago, to further improve our patients' overall rehabilitation.These applications include all stages of prosthetic care from planning, design through device delivery, and for lifetime maintenance. The collaboration among surgeons and anaplastologists is fundamental to achieving optimal patient outcomes and in the success of our technology-based practice. Such collaboration starts with the patient's decision to proceed with prosthetic rehabilitation and continues with postoperative care and lifetime management of the patient's prosthetic device and prosthesis-bearing soft tissue.Although computer-assistive techniques often represent a substantial financial investment, the benefits of using them demonstrate clear advantages to both the clinician and patient. These benefits include: Improved predictability of outcomes, surgeon preparedness, reduction in operating room time, reduction in overall treatment times, improved precision and anatomical accuracy, improved treatment efficiencies, and overall treatment experience, particularly for those patients traveling great distances for access to care.Representative examples will be presented.

Efficacy and safety of an artificial dermal graft for the reconstruction of exenterated sockets: a preliminary report

PURPOSE

The purpose of this study is to report our experience with the use of artificial dermis grafts for orbital socket reconstruction following orbital exenteration (OE).

METHOD

A retrospective study was conducted in our ocular oncology centre from May 2018 to June 2020 in patients undergoing OE for orbital malignancies in whom an artificial dermis device (Integra® template, 2 layers) was used for reconstruction. Data recorded included demographics, previous and adjuvant treatments, aetiologies, surgical procedure, surgical reconstruction, complications and follow-up. The main outcome measure was the time between OE and the full granulation of the cavity.

RESULTS

Ten patients (mean age, 71.3 years [43-92]) were included. Tumours originated from the conjunctiva (n = 5, 50%), eyelid (n = 3, 30%) and orbit (n = 2, 20%). Nine patients underwent total OE, and one required enlarged OE. Orbital reconstruction was performed using an artificial dermis alone (n = 9, 90%) or combined with regional flaps (n = 1, 10%). The mean granulation time was 3.3 weeks (2-4). Three (30%) patients received adjuvant radiotherapy 1 month post-surgery. The mean time to spontaneous epithelialization was 9.4 weeks (6-12). Preoperative and postoperative radiotherapy was not associated with a delayed epithelialization of the socket (p = 0.463 and p = 0.236, respectively). One (10%) and 2 (20%) patients experienced postoperative socket infection and an ethmoidal fistula, respectively. The mean follow-up was 11.6 months (6-16).

CONCLUSION

Using artificial dermis grafts alone or with regional flaps appears to be a viable surgical procedure for orbital socket reconstruction. They reduce surgical morbidity and hospital stay. Preoperative and postoperative radiotherapy does not seem to delay socket healing.

An implant-supported prosthetic rehabilitation of a patient with a bilateral subtotal maxillectomy defect secondary to rhino-orbital-cerebral mucormycosis: A clinical report of a graftless approach

This clinical report presents the rehabilitation of extensive hard and soft tissue defects caused by rhino-orbital-cerebral mucormycosis as a result of untreated diabetes mellitus. The patient underwent subtotal maxillectomy and was rehabilitated with an implant-supported maxillofacial prosthesis with zygomatic and pterygoid implants by following an immediate loading protocol.