Dental implants in oral cancer reconstruction

Implant Survival in Tissue-Engineered Mandibular Reconstruction-Early Experiences

Study Design

This article is to evaluate the early outcomes of dental implants placed in bone generated with tissueengineering techniques, specifically recombinant human bone morphogenic protein-2 (rhBMP-2), allogeneicbone particulate, and bone marrow aspirate concentrate (BMAC) in patients with resection of benignpathology.

Objective

To evaluate the long-term prognosis of dental implants placed in tissue engineered mandibular reconstruction.

Methods

We retrospectively evaluated 12 patient records, all of whom underwent segmental mandibular resection of benign pathology and reconstruction with a combination of BMAC, rhBMP-2, and allogeneic bone. Collecteddata points included the patient's age, gender, medical and social histories, implant site and placement date, resection/reconstruction date, final prosthesis, pathology resected, and follow-up dates (average 25 monthsof follow-up). Implant success was defined as clinical osseointegration (immobility), absence of peri-implantradiolucency, and absence of infection.

Results

Twelve patients met inclusion criteria with a total of 46 implants. The overall implant survival rate was 91.3%. There were 4 implant failures occurring in two patients: 1 failure in Patient 3 and 3 failures in Patient 8. Neitherpatient had any existing medical comorbidities or social history known to increase the risk for implant failure. The average implant placement occurred 11.6 months after mandibular reconstruction.

Conclusions

Preliminary findings of implant placement in bone generated with tissue engineering techniques have shown to be another predictable alternative for orofacial rehabilitation. Practical Implications: Dental rehabilitationusing dental implants is a predictable treatment option for patients that have required reconstruction of largebony defects status post resection of benign pathology using novel tissue engineering techniques.

Prosthetic Rehabilitation Options in Post-Ablative Maxillomandibular Microvascular Reconstructions

Objective

Surgery remains the mainstay for managing most neoplasms arising in the head and neck area. Removable or fixed prostheses are commonly used for prosthetic rehabilitation of head and neck defects following surgical resection. Some major challenges in prosthetic rehabilitation after maxillomandibular microvascular reconstruction include excessive prosthetic space, soft tissue bulk, and occlusal disharmony in the remaining dentition. This review focuses on the challenges we have experienced in the real clinical scenario while rehabilitating reconstructed maxillomandibular defects and the effective prosthetic treatment options that could be considered in each situation.

Discussion

Digital revolution has changed all arenas of life, and it has created a significant impact on cancer treatment planning and the delivery of quality treatment to the needy. Creating adequate retention while ensuring stability and support for the prosthesis can be challenging with temporary acrylic and cast partial removable dentures. Endosseous dental implants are considered a stable, reliable, and esthetic option for reconstruction with advantages such as increased chewing efficiency, preservation of the remaining bone height and width, and improved quality of life. The FP3 to RP5 (Misch's classification) are some commonly followed prosthetic rehabilitation options after microvascular reconstruction. The prosthetic design should permit the usage of interdental aids that ensure the longevity of prostheses.

Conclusion

Occlusion-driven/prosthetic-driven implant-assisted prostheses are considered a reliable option that ensures stable and functional oral rehabilitation among patients with free fibula flap reconstruction. Multidisciplinary teamwork is mandatory for an optimal outcome that improves patients' quality of life.

The role of computer aided design/computer assisted manufacturing (CAD/CAM) and 3- dimensional printing in head and neck oncologic surgery: A review and future directions

Microvascular free flap reconstruction has remained the standard of care in reconstruction of large tissue defects following ablative head and neck oncologic surgery, especially for bony structures. Computer aided design/computer assisted manufacturing (CAD/CAM) and 3-dimensionally (3D) printed models and devices offer novel solutions for reconstruction of bony defects. Conventional free hand techniques have been enhanced using 3D printed anatomic models for reference and pre-bending of titanium reconstructive plates, which has dramatically improved intraoperative and microvascular ischemia times. Improvements led to current state of the art uses which include full virtual planning (VP), 3D printed osteotomy guides, and patient specific reconstructive plates, with advanced options incorporating dental rehabilitation and titanium bone replacements into the primary surgical plan through use of these tools. Limitations such as high costs and delays in device manufacturing may be mitigated with in house software and workflows. Future innovations still in development include printing custom prosthetics, 'bioprinting' of tissue engineered scaffolds, integration of therapeutic implants, and other possibilities as this technology continues to rapidly advance. This review summarizes the literature and serves as a summary guide to the historic, current, advanced, and future possibilities of 3D printing within head and neck oncologic surgery and bony reconstruction. This review serves as a summary guide to the historic, current, advanced, and future roles of CAD/CAM and 3D printing within the field of head and neck oncologic surgery and bony reconstruction.

What is the optimal timing for implant placement in oral cancer patients? A scoping literature review

BACKGROUND

Oral cancer patients can benefit from dental implant placement. Traditionally, implants are placed after completing oncologic treatment (secondary implant placement). Implant placement during ablative surgery (primary placement) in oral cancer patients seems beneficial in terms of early start of oral rehabilitation and limiting additional surgical interventions. Guidelines on the ideal timing of implant placement in oral cancer patients are missing.

OBJECTIVE

To perform a scoping literature review on studies examining the timing of dental implant placement in oral cancer patients and propose a clinical practice recommendations guideline.

METHODS

A literature search for studies dealing with primary and/or secondary implant placement in MEDLINE was conducted (last search December 27, 2019). The primary outcome was 5-year implant survival.

RESULTS

Sixteen out of 808 studies were considered eligible. Both primary and secondary implant placement showed acceptable overall implant survival ratios with a higher pooled 5-year implant survival rate for primary implant placement 92.8% (95% CI: 87.1%-98.5%) than secondary placed implants (86.4%, 95% CI: 77.0%-95.8%). Primary implant placement is accompanied by earlier prosthetic rehabilitation after tumor surgery.

CONCLUSION

Patients with oral cancer greatly benefit from, preferably primary placed, dental implants in their prosthetic rehabilitation. The combination of tumor surgery with implant placement in native mandibular bone should be provided as standard care.

Implant survival in patients with oral cancer: A 5-year follow-up

Background

To evaluate the evolution of patients rehabilitated with endosseous implants after oral cancer treatment.

Material and Methods

An observational retrospective study was carried out between 1991 and 2011 with a sample consisting of patients with oral cancer who had been referred for rehabilitation to the Prosthetics Rehabilitation Unit from the Oral and Maxillofacial Surgery Unit of the Virgen del Rocío University Hospital. All these patients have overcome oral cancer, and have a five-year follow-up after their oral rehabilitation. Age, sex, smoking habits, oral pathology, type of treatment of oral pathology, edentulism, receptor bone, prosthetic rehabilitation, timeouts, working time and evolution were studied. SPSS Statistics was used for statistical analysis of the variables studied. A chi-square test centered on the survival rate of implants placed in relation to the other recorded variables was performed.

Results

17 patients were treated for cancer and rehabilitated with implant prosthetics, with a total of 106 implants placed. 32% were partially edentulous patients (4 patients), and 68.2% were completely edentulous patients (13 patients). An implant survival rate of 87.7% was observed at 5 years. In the upper maxilla, the survival rate was 79.2%, and in the mandible 93.7% (p = 0.03). 91 implants were placed in native receptor bones (85.8%), with only 15 implants placed in grafted receptor bone (14.2%). According to the type of receptor bone, in native receptor bones, 9 implants failed (90.1% of implant survival), while in grafted receptor bones, 4 implants failed (overall 73.3% implant survival rate) (p = 0.08).

Conclusions

Although a high survival rate was obtained in this study (with lower survival rates seen in mandible and grafted bone), prospective long-term studies are needed to assess the relationship between radiotherapy doses and the time required for implant placement, prosthetic protocol used, and type of implants used in patients selected for prosthetic rehabilitation. Key words:Dental implant, oral cancer, survival.

Iliac crest bone grafting for mandibular reconstruction: 10-year experience outcomes

Purpose

To evaluate 10-year patient data related to mandibular reconstruction with NVBG at a tertiary academic center.

Patients and Methods

Sixty patients with mandibular mandibular reconstruction were included. Patients were divided to continuity defect and non-continuity defect. Pathology lesion, immediate reconstruction, smoking habit, medical comorbidities, site and size of the defect, surgical approach, intraoperative perforation, cadaveric bone use, and maxilla-mandibular fixation use were analyzed as factors of influence on success. Success was defined as maintenance of more than 50% of graft for non-continuity defects (NCD) and bone continuity and stability for continuity defect (CD), and absence of infection on last follow up upon clinical and radiographic examination. Complications were classified as minor or major.

Results

The reconstruction was successful in 28 (87%) of CD patients and 23 (82.1%) of NCD patients. Analyses showed that the size of defect was significantly associated with failure. All 4 failed cases of CD had defects more than 9 cm. Four patients had major complications and 43 minor complication.

Conclusions

Nonvascularized iliac crest bone grafts are highly successful in mandibular continuity reconstruction for non-Cancer patients and should be considered as first choice for defects less than 9 cm. They are less predictable for defects larger than 9 cm but can be considered in these cases with osteoconductive cribs. Symphysis involvement may or may not be associated with lower success rate if our protocol is followed.

Is a Fixed Hybrid Prosthesis with Distal Cantilever Appropriate for Maxillofacial Defects? A Report of Two Patients

The most important objectives in restoring the maxillofacial patient are the restoration of function and psychological improvement through esthetics. Acquired maxillary and mandibular defects due to significant trauma or surgery represent a major challenge for the clinician and patient. Dental implant-retained prostheses represent a well-documented and reliable treatment option and can also help patients with maxillofacial defects by eliminating denture instability and improving function. Full-arch fixed dental hybrid prostheses provide functional and psychological advantages and also reduce the load on vulnerable soft and hard tissues in the reconstruction area. Two clinical reports are presented describing the prosthetic rehabilitation using dental implant-supported fixed hybrid prostheses with clinical and radiographic follow-up of 3 years.

Sub-Periosteal Dissection with Denture-Guided Epithelial Regeneration: A Novel Method for Peri-Implant Soft Tissue Management in Reconstructed Mandibles

BACKGROUND

In patients with reconstructed mandibles using free fibula flaps, management of soft tissues around implants supporting dental rehabilitation, is often a clinical problem.

AIM

The aim of this paper is to describe a new technique, namely "Sub-periosteal dissection and denture-guided epithelial regeneration (SD-DGER)", as a method of peri-implant soft tissue management in these patients.

MATERIALS AND METHODS

The technique consists of performing a subperiosteal dissection with creation of buccal and lingual flaps. These flaps form the buccal and lingual vestibule. Implants are placed and an interim denture is immediately loaded onto the implants to guide the regenerated epithelium. A keratinized mucosal layer is formed on the bare fibula bone in six months time.

RESULTS

This technique was successful in producing fixed keratinized epithelial tissue around implants in patients with mandibles reconstructed using the free fibula flap in patients who did not undergo radiotherapy.

CONCLUSION

The sub-periosteal dissection with denture guided epithelial regeneration is a predictable form of peri-implant soft tissue management in selected patients with reconstructed jaws.

Mandibular fibular graft reconstruction with CAD/CAM technology: A clinical report and literature review

This clinical report describes the treatment of a partially dentate patient who presented with dental implants placed in a reconstructed fibula graft in the mandible. A complete mouth rehabilitation with a maxillary complete denture and a mandibular implant-supported fixed complete denture was fabricated with computer-aided design and computer-aided machining technology.

Zygoma implant reconstruction of acquired maxillary bony defects

The reconstruction of acquired maxillary bony defects after pathologic ablation, infectious debridement, avulsive trauma, or previously failed reconstructions with zygoma implants represents a treatment alternative that is safe, predictable, and cost-effective. Still the single most important factor for treatment success of these complex reconstructions is the implementation of a team approach between the surgeon and the restorative dentist. The focus of this article is to review the surgical and prosthetic nuances to successfully reconstruct acquired maxillary defects with zygoma implants.