Stability of dental implants in microvascular osseous transplants

Prosthodontic complications during implant-based oral rehabilitation of patients with head and neck cancer

STATEMENT OF PROBLEM

Implant-retained prosthodontic rehabilitation of patients with head and neck cancer is complex. However, the extent of prosthodontic complications has been sparsely reported within the literature.

PURPOSE

The purpose of this retrospective study was to describe the range of complications and issues that affected the oral rehabilitation treatment of patients with head and neck cancer who had completed implant-retained prosthodontic rehabilitation in a tertiary treatment center.

MATERIAL AND METHODS

A retrospective analysis of complications and their consequences in patients treated in a regional unit from 2012 to 2017 was performed. Descriptive analysis was carried out on the type and frequency of complications and their consequences for the patients' treatment. Complications were grouped into the following complication types: local and systemic, implant, peri-implant soft tissue, and clinical prosthodontic complications. Implant success and implant survival were also reported.

RESULTS

The sample was composed of 163 patients with head and neck cancer who had completed implant-retained prosthodontic rehabilitation. Local and systemic complications affected 8.6% of patients, and peri-implant soft-tissue complications affected 9.8% of patients. Clinical prosthodontic complications leading to repeated clinical or laboratory stages occurred on 48 occasions in 45 patients (27.6% of patients). A total of 763 implants were placed. Implant survival was 95.8% and implant success 94.5%, with a mean follow-up of 42.1 months.

CONCLUSIONS

This retrospective evaluation indicated that complications arising during the process of implant-retained prosthetic rehabilitation in this patient group were variable and common. Such complications can delay the process of treatment and lead to repeating or restarting clinical and laboratory stages of treatment.

Analysis of intraoral microvascular anastomosis in maxillofacial defects reconstruction

This review summarizes the research progress in the field of intraoral microvascular anastomosis techniques (IAT) and attempts to investigate the indications for procedures in which IAT can be applied, the surgical procedure and the difficulties involved, technical assessments, result evaluation and the perspective. Currently, microvascular anastomosis technique is widely used in maxillofacial defects reconstruction from various causes including cutaneous injury or congenital deformity which usually required extensive flap reconstruction and therefore a vascular free flap is routinely used. Conventional microvascular anastomosis reconstruction techniques cannot avoid new incisions, which will affect the postoperative aesthetic situation. Surgeons have therefore attempted to improve this technique to effectively eliminate scars caused by surgery: some patients can be chosen to undergo microvascular anastomosis of the free flap intraorally, thus reducing the extraoral incision caused by the anastomosis located in neck or maxillofacial improving the postoperative appearance of the patients. In addition to preserving the external appearance, intraoral anastomosis technique (IAT) can also solve some other problems of maxillofacial vascular anastomosis, such as insufficient vessel pedicle length and high risk of facial nerve injury.

Complex Mandibular Reconstruction for Head and Neck Squamous Cell Carcinoma-The Ongoing Challenge in Reconstruction and Rehabilitation

Simple Summary

Cancer therapy includes a broad range of microvascular free flaps that may restore defects and improve patients’ quality of life. This is particularly important for head and neck squamous cell carcinoma (HNSCC) and composite mandibular reconstructions, containing tissues of bone, muscle, and skin, which may be problematic due to their magnitude and sensitive location. The subscapular system offers a highly valuable donor site with the most versatility and the potential for rapid rehabilitation. Interestingly, other donor sites are more commonly used internationally. Therefore, we evaluated the use of the subscapular system free flap (SFF), which is the most commonly used free flap at our department. To our knowledge, this retrospective study represents the largest number of SFF cases reported to date in the literature. Furthermore, we examined the quality of life in a subgroup of patients, combining prospective occurrences to provide insight into overall rehabilitation from the patients’ viewpoints.

Abstract

Large head and neck squamous cell carcinoma (HNSCC) tumors affecting the mandible require a versatile reconstruction to maintain form, function, and quality of life. Large defect reconstruction of soft and hard tissue in the head and neck necessitates, at best, one vascular system including various tissues by large dimensions. The subscapular flap system seems to meet these standards. A retrospective study was conducted focusing on clinical data, including an analysis of the quality of life with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaires, (QLQ-C30 and QLQ-H&N43). A total of 154 patients (122 males, 32 females; age range: 31–71 years, mean: 54.5 years) treated at our department from 1983 through to 2019 were included. Of the subscapular system free flaps (SFFs), 147 were based on the angular artery branch of the thoracodorsal pedicle (95.45%), and the remaining seven cases (4.55%) were lateral scapular border flaps. Mean mandible defect length was 7.3 cm. The mean skin paddle dimension was 86.8 cm². The most common recipient artery was the thyroid superior artery (79.22%). Major postoperative complications occurred in 13 patients (8.44%). This study confirms that SFFs offer excellent soft and hard tissue quality, component independence, a large arc of rotation length, and a large gauge of pedicle, making them the gold standard for the reconstruction of large composite defects of mandibular HNSCC tumors.

Survival of dental implants placed in autogenous bone grafts and bone flaps in head and neck oncology patients: a systematic review

Using implants to retain prostheses as part of the oral rehabilitation of head and neck cancer patients is an increasingly common treatment modality, particularly in transported bone which is used to reconstruct defects following oncological surgical resection. The aim of this systematic review is to evaluate the survival of dental implants placed into autogenous bone grafts and flaps, in head and neck cancer patients. MEDLINE, EMBASE, CENTRAL and Science Direct databases were searched (1980-August 2017) for studies evaluating intra-oral implant placement into autogenous bone grafts and flaps in H&N cancer patients. Twenty articles were included reporting on 1905 implants placed into autogenous bone in head and neck cancer patients. Implant survival varied from 54 to 100% within the studies with 11 studies reporting implant survival of over 90%. In conclusion, intra-oral implant survival in autogenous bone grafts in head and neck oncology patients is promising, however inconsistencies in data reporting and in outcome definitions precludes formal meta-analysis.

Implant rehabilitation in fibula-free flap reconstruction: A retrospective study of cases at 1-18 years following surgery

PURPOSE

To determine the dental implant and prostheses success rate in a cohort of patients who underwent a vascularized fibula-free flap (FFF) for maxillary or mandibular reconstruction.

METHODS

The investigators implemented a retrospective cohort study composed of patients who had undergone primary or secondary FFF reconstruction jaw surgery plus placement of 2-6 implants in the reconstructed arch, which were restored with an implant-supported prosthesis. The sample was composed of all patients who underwent FFF surgery between 1998 and 2012 and had either simultaneous or secondary dental implant placement. A total of 28 patients met inclusion criteria. Of these, 22 patients participated in the retrospective review. Patients were examined by an independent observer between January-December 2015. In addition, all patients completed a questionnaire to access satisfaction with the implant-supported prosthesis.

RESULTS

The patient cohort consisted of 12 males and 10 females, age 12-70 years. A total of 100 implants were placed, 92 implants in fibular bone and 8 implants in native bone. In the maxilla, 35 implants were placed into fibular bone and 4 into native bone (11 in irradiated patients and 28 in non-irradiated patients). In the mandible, 57 implants were placed into fibular bone and 4 into native bone (15 in irradiated patients and 46 in non-irradiated patients). The mean follow-up after implant loading was 7.8 years (range 1.3-17.5 years). The implant survival rate was 98% (95% CI: 92.2%-99.5%). No statistically significant difference was found in implant success between maxillary and mandibular implants, or between radiated and non-radiated bone. The prostheses success rate, determined by clinical exam and patient satisfaction, was 100%.

CONCLUSION

The results of this study suggest that implant survival is high and implant-supported prostheses are a reliable rehabilitation option in patients whose jaws have been reconstruction with a FFF.

Rehabilitation with dental implants in microvascular iliac graft after solid ameloblastoma resection: a case report

PURPOSE

Ameloblastoma is a true odontogenic tumor that is most frequently found in clinical practice. Osseous resection with clear margins is the recommended treatment followed by bone reconstruction, such as a vascularized graft. The use of osseointegrated dental implants for rehabilitation is advisable, as it allows the recovery of the masticatory function.

MATERIALS AND METHODS

This case report includes 1 subject, a patient who presented with a large ameloblastoma treated by resection, a microvascular iliac graft, and dental implants.

RESULTS

After 6 months of regular control, the patient exhibited perfect healing of both the soft tissues and bone graft. At the time of this report, the patient had undergone 36 months of clinical and radiographic follow-up and had not exhibited any sign of osseous loss, implant mobility, or tumor recurrence.

CONCLUSIONS

The outcome of this case indicates that a microvascular graft and subsequent dental implantation is a good treatment plan that aids in a quick functional rehabilitation in ameloblastoma patients.

The Microvascular Corticocancellous Femur Flap for Reconstruction of the Anterior Maxilla in Adult Cleft Lip, Palate, and Alveolus Patients

Objective

Free nonvascularized alveolar bone grafting in severe defects of the cleft region often results in poor implant bed conditions. Here an alternative augmentation technique using a new technique of vascularized bone transfer is described.

Design

In five patients with clefts of the lip, palate, and alveolus (four unilateral, one bilateral) there was a severe defect of the anterior maxillary alveolar ridge after tooth loss. The patients previously had augmentative surgery one to three times without success. The defect was covered using a microvascular corticocancellous transplant from the medial distal femur. The defects to be corrected measured 2.5 to 4.0 cm long, 1.0 to 1.5 cm wide, and 1 to 1.5 cm high. The microvascular pedicle of the femur bone flap was 3 to 7 cm long. The descending genicular artery was anastomosed to the facial or labial superior artery and the accompanying veins accordingly. In every case, the anastomoses were performed via an intraoral transmucosal approach.

Results

There were no serious complications and no flap loss. In all patients the defect was covered by a flap of the correct size and design. All patients were treated with dental implants (13 total) 6 months after successful reconstruction of the ridge. The implants were loaded 4 to 6 months after placement with fixed superstructures. There were good peri-implant conditions and no implant loss.

Conclusion

The microvascular osteoperiosteal femur flap can be used successfully in individual reconstruction of segmental defects of the alveolar ridge in adult cleft patients.

Principles of implant-based reconstruction and rehabilitation of craniofacial defects

The final stages of reconstruction following craniofacial trauma or tumor resection often involve the fitting of prostheses. Development of osseointegrated implants for retention of prostheses has improved function and aesthetic outcome. Placement of osseointegrated implants requires coordinated care from multiple specialists and a lifetime commitment of the patient. The workup and surgical treatment algorithms for placement of intraoral compared with extraoral implants are discussed. The quality and quantity of bone available are the most important factors influencing design and placement. The long-term retention of implants is influenced by implant site, local tissue bed preparation, and hygiene. Osseointegrated implants are a part of the complete rehabilitation of patients with craniomaxillofacial defects. Although final fitting and maintenance of prostheses is completed by prosthodontists and patients, successful placement and preservation of implants is affected largely by the plan set forth by the reconstructive surgeon.

Step-by-step full mouth rehabilitation of a nasopharyngeal carcinoma patient with tooth and implant-supported prostheses: A clinical report

This clinical report presents a 46-year-old man diagnosed with nasopharyngeal carcinoma with the chief complaint of masticatory and speech deficiency because of radiation therapy. After a period of controlling post radiation caries, the patient was rehabilitated with tooth and implant supported metal ceramic restorations following surgical and endodontic intervention.

Implant stability and peri-implant parameters in free vascularized iliac graft transplantation patients: report of three ameloblastoma cases

BACKGROUND

Ameloblastoma, a benign but locally aggressive tumor, accounts for 9% to 11% of all odontogenic tumors. Radical procedures, including resection, are performed. To restore functions after resection, free vascularized iliac grafts followed by a dental implant-supported prosthesis are used as a successful treatment option. The aim of this case report is to evaluate the peri-implant clinical status and stability of dental implants placed in patients with advanced-stage mandibular ameloblastomas.

METHODS

Examinations of three patients revealed extensive ameloblastomas, and hemimandibulectomies were performed. Six months after surgeries, two to four dental implants were placed. After 6 months of healing, one fixed prosthesis and two removable prostheses were delivered. The stability of implants was evaluated at the surgical baseline and 1, 3, 6, 9, and 12 months after surgery by resonance-frequency (RF) analysis. Peri-implant clinical parameters (i.e., plaque index [PI], gingival index [GI], gingival bleeding time index [GBTI], and peri-implant probing depth [PD]) were recorded at the delivery of the prosthesis and at follow-ups at 1, 3, and 6 months.

RESULTS

Nine implants that supported one removable prosthesis and two fixed prostheses were placed. RF analysis revealed no significant changes in implant stability during 12 months of follow-up. Peri-implant clinical parameters (PI, GI, and GBTI) showed slight improvements during follow-up. Although advancements were observed in 6 months, PDs were found to be deeper than optimal measurements for the whole observation time.

CONCLUSION

The implant-supported prosthetic rehabilitation of patients with ameloblastomas reconstructed with free vascularized iliac crest grafts can be a predictive alternative for improving the quality of life of patients in which a high implant stability and acceptable peri-implant health may be achieved.

Comparative study of the osseointegration of dental implants after different bone augmentation techniques: vascularized femur flap, non-vascularized femur graft and mandibular bone graft

OBJECTIVES

The purpose of this study was to evaluate the osseointegration of the dental implants placed into the mandible augmented with different techniques in pigs.

MATERIAL AND METHODS

Four adult domestic pigs were used. Horizontal augmentation of the mandible was performed in animals by using vascularized femur flap (VFF), non-vascularized femur graft (NVFG) and monocortical mandibular block graft (MG). After 5 months of healing 10 dental implants were placed into each augmented site. The pigs were sacrificed after 3 months of healing. Undecalcified sections were prepared for histomorphometric analysis.

RESULTS

Mean bone-implant contact (BIC) values for implants placed into MG, NVFG and VFF were 57.38 ± 11.97%, 76.5 ± 7.88%, 76.53 ± 8.15%, respectively. The BIC values of NVFG and VFF group were significantly greater than MG group (P<0.001). On the other hand, there was not statistically significant difference between NVFG group and VFF group (P=0.999).

CONCLUSION

NVFG as well as VFF can be considered as a promising method for augmentation of alveolar defects and the placement of the implants. The selection of non-vascularized graft or vascularized flap depends on the condition of the recipient site.

Tooth autotransplantation in a free iliac crest graft for prosthetic reconstruction

This report documents successful tooth autotransplantation to a free iliac crest graft in an exemplar case. A 14-year-old male patient was operated thrice with increasing amounts of resection for recurrent odontogenic myxoma. When mandibular continuity resection finally was performed, a free iliac crest block autotransplant was used for reconstruction. Upon metal removal 5 months later, 3 wisdom teeth with two-thirds complete root development were transplanted to the free graft and retained by fixed orthodontic appliances including skeletal anchorage with orthodontic microscrews. Tooth graft taking was awaited for 8 weeks with retention. Following undisturbed healing without occlusal forces, 6 months of orthodontic treatment intentionally extruded the autotransplanted teeth to antagonist contact. The third and most dorsal tooth became mobile after 3 months and was lost. The surviving 2 teeth were fitted by a prosthetic bridge as extrusion into the occlusal plane was not completely successful. This exemplar case shows benefit of tooth autotransplants in selected cases of jaw reconstruction with distal bone autotransplants as alternative to dental titanium implants and suprastructures. Orthodontic microscrews can moreover support tooth movement and positioning as anchorage device in altered anatomy.

Free microvascular transfer of segmental corticocancellous femur for reconstruction of the alveolar ridge

In seven patients with deficiency of the alveolar ridge of the maxilla or mandible the defect was covered with the help of a microvascular corticocancellous transplant of femur. The defects to be corrected measured 3-10 cm long, 1.5-4 cm wide, and 1-1.5 cm high. The microvascular pedicle was between 4 and 10 cm long. The descending genicular artery was anastomosed to the facial or labial superior artery and the accompanying veins accordingly. There were no serious complications and no transplant was lost. In all patients the defect was covered by the correct size and design. All patients were treated with dental implants six months after successful reconstruction of the ridge. The microvascular osteoperiosteal femur transplant can be used successfully in individual reconstruction of segmental defects of the alveolar ridge.

Rehabilitation of oral function in head and neck cancer patients after radiotherapy with implant-retained dentures: effects of hyperbaric oxygen therapy

Surgical treatment of malignancies in the oral cavity and subsequent radiotherapy often result in an anatomic and physiological oral condition unfavorable for prosthodontic rehabilitation. The objective of this prospective study was to assess the effect of hyperbaric oxygen therapy on treatment outcome (condition of peri-implant tissues, implant survival, oral functioning and quality of life) of prosthodontic rehabilitation with implant-retained lower dentures in radiated head and neck cancer patients 6 weeks and 1 year after placing the new dentures. The treatment outcome was assessed in a group of 26 head neck cancer patients who were subjected to radiotherapy after tumour surgery. Standardized questionnaires were completed and clinical and radiographic assessments were performed. After randomization, endosseous Brånemark implants were placed in the anterior part of the mandible either under antibiotic prophylaxis (13 patients) or under antibiotic prophylaxis combined with pre and postsurgery hyperbaric oxygen (HBO) treatment (13 patients). In the HBO and non-HBO group eight implants (implant survival 85.2%) and three implants (implant survival 93.9%) were lost, respectively. Peri-implant tissues had a healthy appearance in both groups. Osteoradionecrosis developed in one patient in the HBO group. All patients functioned well with their implant-retained lower denture. The quality of life related to oral functioning and denture satisfaction were improved to a comparable extent in the HBO and non-HBO group. Implant-retained lower dentures can improve the quality of life related to oral functioning and denture satisfaction in head and neck cancer patients. Adjuvant hyperbaric oxygen therapy could not be shown to enhance implant survival in radiated mandibular jaw bone.

The use of implant retained mandibular prostheses in the oral rehabilitation of head and neck cancer patients. A review and rationale for treatment planning

Surgical treatment of malignancies in the oral cavity (tongue, floor of the mouth, alveolus, buccal sulcus, oropharynx) often results in an unfavourable anatomic situation for prosthodontic rehabilitation. The outcome is a severe disturbance of oral functioning despite the improved surgical techniques for reconstruction that are currently available. Radiotherapy, which often is applied postsurgically, worsens oral functioning in many cases. Main problems that may hamper proper prosthodontic rehabilitation of these patients include a severe reduction of the neutral zone, an impaired function of the tongue, and a very poor load-bearing capacity of the remaining soft tissues and mandibular bone. Many of these problems can, at least in part, be diminished by the use of endosseous oral implants. These implants can contribute to the stabilisation of the prostheses and intercept the main part of the occlusal loading. Surgical interventions after radiotherapy are preferably avoided because of compromised healing, which may lead to development of radionecrosis of soft tissues and bone as well as to increased implant loss. If surgical treatment after radiotherapy is indicated, measures to prevent implant loss and development of radionecrosis have to be considered e.g. antibiotic prophylaxis and/or pre-treatment with hyperbaric oxygen (HBO). To avoid this problem, implant insertion during ablative surgery has to be taken into consideration if postoperative radiotherapy is scheduled or possibly will be applied. This approach is in need of a thorough pre-surgical examination and multidisciplinary consultation for a well-established treatment planning. The primary curative intent of the oncological treatment and the prognosis for later prosthodontic rehabilitation have to be taken into account too.