Oral rehabilitation after treatment for head and neck malignancy

Long-Term Survival of Dental Implants in Irradiated Patients

The surgical ablation of head and neck cancer followed by radiotherapy often leads to unfavorable functional and aesthetic outcomes. Studies have demonstrated that these outcomes can significantly impact quality of life. Dental implants play a crucial role in rehabilitation by facilitating the use of suprastructures and obturators. However, the long-term survival of dental implants in patients who have undergone radiotherapy remains uncertain, raising several questions. These include determining the optimal timing for dental implantation (before or after radiotherapy), identifying the radiotherapy threshold for implant loss, and considering the role of hyperbaric oxygen therapy. These and other related concerns will be addressed in the following article.

Survival rate and complication-free survival rate of implant-retained prostheses in the oral rehabilitation of patients with head and neck cancer: A retrospective evaluation of a cohort from a regional service

STATEMENT OF PROBLEM

Literature reporting on the prosthetic survival and complications of implant-retained prostheses in patients with head and neck cancer is sparse.

PURPOSE

The purpose of this retrospective study was to present the survival rates and complication-free survival rates of both fixed and removable implant-retained oral prostheses in patients with head and neck cancer while also reporting on the frequency and causes of failure and complications for each prosthesis type.

MATERIAL AND METHODS

A retrospective analysis of the prosthetic survival rates and complication-free survival rates of implant-retained oral prostheses and the frequency and causes of failure and complications in patients with head and neck cancer treated in a regional unit from 2012 to 2017 was performed. Differences in categorical and continuous data were assessed for statistical significance by using the Pearson chi-squared test, Fisher exact test, t test, and analysis of variance as appropriate. Cox proportional hazard regression models were fitted to evaluate the association between prostheses type, clinical and medical factors, and the outcomes of survival and complication-free survival. Descriptive statistics were used to analyze the frequency and type of prosthetic complications.

RESULTS

The sample was composed of 153 patients diagnosed with head and neck cancer who had completed implant-retained prosthodontic rehabilitation and had been provided with 221 prostheses. The 5-year survival rate was 87% for maxillary fixed prostheses, 79% for mandibular fixed, 66% for maxillary removable, and 50% for mandibular removable. Hazard ratios were calculated showing that the 5-year survival rate of a mandibular removable prosthesis (HR=5.1; 95% CI 1.60-16.25) (P=.006) was greater than that of a maxillary fixed prosthesis (HR=1.0). The 5-year complication-free survival rate was highest for mandibular fixed prostheses (62%), followed by maxillary fixed (58%), maxillary removable (36%), and mandibular removable prostheses (29%). Hazard ratios showed that the 5-year survival rate of maxillary removable (HR=1.91; 95% CI 1.01-3.66) (P=.048) and mandibular removable prosthesis (HR=2.29; 95% CI 1.23-4.25) (P=.009) was greater than that of a maxillary fixed prosthesis (HR=1.0). Variables of radiotherapy, grafting, age, and sex and their influence on the survival rate and complication-free survival rate were assessed but were not statistically significant.

CONCLUSIONS

This evaluation indicated that fixed implant-retained prostheses had a higher 5-year survival rate and 5-year complication-free survival rate than removable implant-retained prostheses in patients with head and neck cancer.

Long-term survival and success rate of dental implants placed in reconstructed areas with extraoral autogenous bone grafts: A systematic review and meta-analysis

OBJECTIVE

To evaluate the long-term survival and success rates of implants placed in reconstructed areas using microvascularized or non-microvascularized extraoral bone grafts.

MATERIALS AND METHODS

An electronic search was performed in five databases and in gray literature for articles published until June, 2023. The eligibility criteria comprised observational studies (prospective or retrospective) and clinical trials, reporting survival and success rates of implants placed in extraoral bone grafts. A meta-analysis (implant failure) was categorized into subgroups based on the type of bone graft used. The risk of bias within studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

Thirty-one studies met the inclusion criteria. The mean follow-up time was 92 months. The summary estimate of survival rate at the implant level were 94.9% (CI: 90.1%-97.4%) for non-vascularized iliac graft, 96.5% (CI: 91.4%-98.6%) for non-vascularized calvaria graft, and 92.3% (CI: 89.1%-94.6%) for vascularized fibula graft. The mean success rate and marginal bone loss (MBL) were 83.2%; 2.25 mm, 92.2%; 0.93 mm, and 87.6%; 1.49 mm, respectively.

CONCLUSIONS

Implants placed in areas reconstructed using extraoral autogenous bone graft have high long-term survival rates and low long-term MBLs. The data did not demonstrate clinically relevant differences in the survival, success, or MBL of grafts from different donor areas or with different vascularization. This systematic review was registered in INPLASY under number INPLASY202390004.

Optimal Treatment Order With Fibula-Free Flap Reconstruction, Oncologic Treatment, and Dental Implants: A Systematic Review and Meta-Analysis

Head and neck cancer (HNC) patients benefit from craniofacial reconstruction, but no clear guidance exists for rehabilitation timing. This meta-analysis aims to clarify the impact of oncologic treatment order on implant survival. An algorithm to guide placement sequence is also proposed in this paper. PubMed, Embase, and Web of Science were searched for studies on HNC patients with ablative and fibula-free flap (FFF) reconstruction surgeries and radiotherapy (RTX). Primary outcomes included treatment sequence, implant survival rates, and RTX dose. Of 661 studies, 20 studies (617 implants, 199 patients) were included. Pooled survival rates for implants receiving >60 Gy RTX were significantly lower than implants receiving < 60 Gy (82.8% versus 90.1%, P =0.035). Placement >1 year after RTX completion improved implant survival rates (96.8% versus 82.5%, P =0.001). Implants receiving pre-placement RTX had increased survival with RTX postablation versus before (91.2% versus 74.8%, P <0.001). One hundred seventy-seven implants were placed only in FFF with higher survival than implants placed in FFF or native bone (90.4% versus 83.5%, P =0.035). Radiotherapy is detrimental to implant survival rates when administered too soon, in high doses, and before tumor resection. A novel evidence-based clinical decision-making algorithm was presented for utilization when determining the optimal treatment order for HNC patients. The overall survival of dental prostheses is acceptable, reaffirming their role as a key component in rehabilitating HNC patients. Considerations must be made regarding RTX dosage, timing, and implant location to optimize survival rates and patient outcomes for improved functionality, aesthetics, and comfort.

Ultrastructural and immunohistochemical evaluation of hyperplastic soft tissues surrounding dental implants in fibular jaws

In reconstructive surgery, complications post-fibula free flap (FFF) reconstruction, notably peri-implant hyperplasia, are significant yet understudied. This study analyzed peri-implant hyperplastic tissue surrounding FFF, alongside peri-implantitis and foreign body granulation (FBG) tissues from patients treated at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Using light microscopy, pseudoepitheliomatous hyperplasia, anucleate and pyknotic prickle cells, and excessive collagen deposition were observed in FFF hyperplastic tissue. Ultrastructural analyses revealed abnormal structures, including hemidesmosome dilation, bacterial invasion, and endoplasmic reticulum (ER) swelling. In immunohistochemical analysis, unfolded protein-response markers ATF6, PERK, XBP1, inflammatory marker NFκB, necroptosis marker MLKL, apoptosis marker GADD153, autophagy marker LC3, epithelial-mesenchymal transition, and angiogenesis markers were expressed variably in hyperplastic tissue surrounding FFF implants, peri-implantitis, and FBG tissues. NFκB expression was higher in peri-implantitis and FBG tissues compared to hyperplastic tissue surrounding FFF implants. PERK expression exceeded XBP1 significantly in FFF hyperplastic tissue, while expression levels of PERK, XBP1, and ATF6 were not significantly different in peri-implantitis and FBG tissues. These findings provide valuable insights into the interconnected roles of ER stress, necroptosis, apoptosis, and angiogenesis in the pathogenesis of oral pathologies, offering a foundation for innovative strategies in dental implant rehabilitation management and prevention.

A comparison of accuracy among different approaches of static-guided implant placement in patients treated with mandibular reconstruction: A retrospective study

OBJECTIVE

This study aimed to evaluate the differences in the accuracy of immediate intraoral, immediate extraoral, and delayed dental implant placement with surgical guides (static computer-aided implant surgery) in patients treated with mandibular reconstruction.

METHODS

This was a retrospective study. The patients were divided into three groups: immediate intraoral placement (IIO), immediate extraoral placement (IEO), and delayed placement (DEL). Four variables were used to compare the planned and actual implant positions: angular deviation, three-dimensional (3D) deviation at the entry point of the implant, 3D deviation at the apical point of the implant, and depth deviation.

RESULTS

The angular deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. The 3D deviation at the entry point was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .01) groups. The 3D deviation at the apical point was significantly higher in the IIO group than in the IEO (p < .01) and DEL (p < .01) groups. The depth deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. There was no statistical difference between the IEO and DEL group in angular and 3D deviation.

CONCLUSION

With surgical guides, among the different approaches for implant placement, delayed implant placement remains the most accurate approach for patients treated with mandibular reconstruction.

Peri-implant health after microvascular head and neck reconstruction-A retrospective analysis

INTRODUCTION

Prosthodontic rehabilitation after reconstruction with microvascular revascularized free flaps following ablative tumor surgery is challenging due to the altered anatomical and functional conditions. The aim of this retrospective study was to determine whether the type of graft and the type of peri-implant tissue have an effect on peri-implant inflammatory parameters and implant survival.

MATERIALS AND METHODS

Patients who received a free flap reconstruction with subsequent implant-prosthetic rehabilitation between 2010 and 2022 were retrospectively included. The primary outcome variable was the probing depth (PPD) at a minimum of 1 year after completion of prosthetic restoration. Predictive variables were type of free flap, emergence profile, and history of radiation.

RESULTS

Seventy-one patients after free flap reconstruction were included in the analysis. At a minimum of 24 months after implant insertion the primary outcome, PPD showed no clinically relevant differences between the types of free flaps used. The emergence profile through a skin island resulted in an increase in BOP compared to native mucosa in the descriptive analysis (p-value > .05). The analysis showed a 5-year implant survival of 96.2% (95% CI: 0.929-0.996) in cases without irradiation and 87.6% (95% CI: 0.810-0.948) with irradiation of the region evaluated (p-value .034).

CONCLUSION

Flap and associated soft tissue type had no significant effect on 5-year implant survival or peri-implant inflammatory parameters. However, the large heterogeneity of the patient population indicates that further prolonged studies are required for a more differentiated assessment of the long-term success.

Survival of dental implants and occurrence of mucosal overgrowth in patients with head and neck cancer treated with/without radiotherapy and mucosal graft-two-year follow-up

OBJECTIVES

The primary aim of the present study was to compare head and neck cancer treatment modality surgery and surgery with radiotherapy or chemoradiotherapy alone for dental implant (DI) survival. The second aim was to evaluate the prevalence of mucosal overgrowth around DI after treatment with or without mucosal grafts.

MATERIALS AND METHODS

An observational retrospective study consisted of 59 patients with malignant head and neck tumors that received DI between 2015 and 2019. Treatment modalities together with information on oral rehabilitation with DI, prevalence of mucosal overgrowth, and precursor lesions were gathered from the hospital records. Radiation doses were determined using a sum of three-dimensional dose distributions.

RESULTS

Overall DI survival rate was 88%, in irritated jaw 89%, and in nonirradiated jaw 88% in this observational period (p = 0.415, mean follow-up was 2 years 10 months, range 9-82 months). Mucosal overgrowth was found in 42 of 196 implants (21%), of which 36 cases (86%) were associated in grafted areas (p < 0.001). Oral lichen planus/lichenoid reaction was diagnosed in 14 of all 59 (24%) oral cancer patients.

CONCLUSION

Implant survival was not significantly influenced by radiation therapy in this observational period. In grafted bone, implant survival was significantly inferior than in native bone. Mucosal overgrowth around implants was more common in mucosal grafted areas versus nongrafted.

CLINICAL RELEVANCE

This study demonstrates the impact of grafted bone to dental implant survival rate and mucosal overgrowth.

Bone Tissue Engineering (BTE) of the Craniofacial Skeleton, Part I: Evolution and Optimization of 3D-Printed Scaffolds for Repair of Defects

Bone tissue regeneration is a complex process that proceeds along the well-established wound healing pathway of hemostasis, inflammation, proliferation, and remodeling. Recently, tissue engineering efforts have focused on the application of biological and technological principles for the development of soft and hard tissue substitutes. Aim is directed towards boosting pathways of the healing process to restore form and function of tissue deficits. Continued development of synthetic scaffolds, cell therapies, and signaling biomolecules seeks to minimize the need for autografting. Despite being the current gold standard treatment, it is limited by donor sites' size and shape, as well as donor site morbidity. Since the advent of computer-aided design/computer-aided manufacturing (CAD/CAM) and additive manufacturing (AM) techniques (3D printing), bioengineering has expanded markedly while continuing to present innovative approaches to oral and craniofacial skeletal reconstruction. Prime examples include customizable, high-strength, load bearing, bioactive ceramic scaffolds. Porous macro- and micro-architecture along with the surface topography of 3D printed scaffolds favors osteoconduction and vascular in-growth, as well as the incorporation of stem and/or other osteoprogenitor cells and growth factors. This includes platelet concentrates (PCs), bone morphogenetic proteins (BMPs), and some pharmacological agents, such as dipyridamole (DIPY), an adenosine A 2A receptor indirect agonist that enhances osteogenic and osteoinductive capacity, thus improving bone formation. This two-part review commences by presenting current biological and engineering principles of bone regeneration utilized to produce 3D-printed ceramic scaffolds with the goal to create a viable alternative to autografts for craniofacial skeleton reconstruction. Part II comprehensively examines recent preclinical data to elucidate the potential clinical translation of such 3D-printed ceramic scaffolds.

Factors Affecting Complete Oral Rehabilitation in Patients With Vascularized Free Fibula Flap Mandibular Reconstruction: A 10-Year Retrospective Study

The fibula is the preferred bone flap for mandibular reconstructions due to its many advantages, including the possibility to insert dental implants. All patients who received a mandibular reconstruction with a vascularized free fibula flap at the Uppsala University Hospital between 2009 and 2019 were retrospectively examined regarding the proportion of implant insertion and factors that affected implant outcome. Forty-one patients had 42 fibula flap reconstructions. Eleven patients (27%) received dental implants and 8 (20%) completed dental rehabilitation. Patient death and cancer recurrence were the main reasons for not receiving implants. The survival rates of implants placed in irradiated and nonirradiated fibulas were 15% and 76%, respectively. Less than 20% of reconstructed patients received an implant-supported prosthesis. Implants placed in an irradiated fibula should be considered at high risk for implant loss.

Three-Dimensional Printing Bioceramic Scaffolds Using Direct-Ink-Writing for Craniomaxillofacial Bone Regeneration

Defects characterized as large osseous voids in bone, in certain circumstances, are difficult to treat, requiring extensive treatments which lead to an increased financial burden, pain, and prolonged hospital stays. Grafts exist to aid in bone tissue regeneration (BTR), among which ceramic-based grafts have become increasingly popular due to their biocompatibility and resorbability. BTR using bioceramic materials such as β-tricalcium phosphate has seen tremendous progress and has been extensively used in the fabrication of biomimetic scaffolds through the three-dimensional printing (3DP) workflow. 3DP has hence revolutionized BTR by offering unparalleled potential for the creation of complex, patient, and anatomic location-specific structures. More importantly, it has enabled the production of biomimetic scaffolds with porous structures that mimic the natural extracellular matrix while allowing for cell growth-a critical factor in determining the overall success of the BTR modality. While the concept of 3DP bioceramic bone tissue scaffolds for human applications is nascent, numerous studies have highlighted its potential in restoring both form and function of critically sized defects in a wide variety of translational models. In this review, we summarize these recent advancements and present a review of the engineering principles and methodologies that are vital for using 3DP technology for craniomaxillofacial reconstructive applications. Moreover, we highlight future advances in the field of dynamic 3D printed constructs via shape-memory effect, and comment on pharmacological manipulation and bioactive molecules required to treat a wider range of boney defects.

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.

Application of a vascularized bone free flap and survival rate of dental implants after transplantation: A systematic review and meta-analysis

PURPOSE

As maxillofacial surgical techniques have advanced, vascularized bone free flap transplantation has become the standard treatment for repairing maxillofacial defects. In this meta-analysis, we summarize the survival rates of implants after VBFF surgery for maxillary and mandibular reconstructions and investigate the factors affecting patient outcomes.

METHODS

The PubMed, Embase, and Wanfang databases were searched up to May 31, 2022. The results of the treatment effect are presented as the risk ratio or odds ratio, using 95% confidence intervals. Statistical significance was calculated at α = 0.05 (two-tailed z tests).

RESULTS

35 studies were included in our analysis. The results revealed a 3-year and 5-year implant survival rate of 95.2% and 85.4% in VBFFs, respectively. The location of jaw defects (maxilla or mandible) or timing of implantation was not found to have a statistically significant influence on the survival rate. However, statistically significant differences were observed in the failure of implants placed in irradiated bone tissue.

CONCLUSIONS

Statistically significant differences were not found in the implant survival rate between simultaneous and delayed implantation, or between maxillary and mandibular defects. However, dental implants placed in irradiated flaps tended to have a lower survival rate than those surgically placed in non-irradiated flaps.

Post-treatment evaluation of oral health-related quality of life in head and neck cancer patients after dental implant rehabilitation

Objectives To assess oral health-related quality of life (OHRQoL) following oral rehabilitation using dental implants in patients treated for head and neck cancer (HNC).Materials and methods Service evaluation: patients who had received dental implants during their oral rehabilitation were invited to take part (n = 81). In total, 37 patients completed questionnaires and underwent a structured interview regarding OHRQoL after rehabilitation. Analysis was by descriptive statistics for questionnaire and thematic analysis of interview.Results Rehabilitation types were 17 fixed implant prostheses, 12 removable implant prostheses and 8 combination. Functional problems relating to HNC treatment had a significant effect on OHRQoL and persisted after rehabilitation. Removable implant prostheses had more problems associated than fixed. At interview, patients described: functional and emotional benefits of oral rehabilitation involving implants; ease of keeping implants clean; variations in ability of primary care dentists to maintain rehabilitation; thankfulness to have received treatment; long duration of rehabilitation; and problems encountered while undergoing rehabilitation.Conclusions HNC treatment results in functional and emotional difficulties, which has a significant impact on OHRQoL. Use of dental implants in fixed or removable oral rehabilitation can result in good OHRQoL as assessed by patients at treatment completion, although some functional difficulties often remain.

Clinical performance of different types of dental prosthesis in patients with head and neck tumors-a retrospective cohort study

OBJECTIVES

To investigate how different types of dental prosthesis perform in patients with head and neck tumors.

MATERIALS AND METHODS

In this retrospective clinical cohort study, the impact of different patient-related factors was analyzed as influencing factors on the survival probability of dental prosthesis using Kaplan-Meier estimate. For analysis, the dental prosthesis was divided into groups: group 1 (fixed dental prosthesis), group 2 (removable dental prosthesis), group 3 (implant-supported dental prosthesis), and group 4 (prostheses anchored using wrought wire clasps and obturators). The incidental aftercare measures were also evaluated.

RESULTS

Two hundred seventy-nine restorations were observed (mean observation: 2.7 ± 3.0 years, max.14.8 years) out of which 49 (17.6%) had to be replaced during the observation. After 5 years, 100% of group 1 restorations, 79.9% of group 2 restorations, 91.4% of group 3 restorations, and 30% of group 4 restorations were still functional. Four hundred eighty-eight dental implants were observed, of which 77 (15.8%) failed.

CONCLUSIONS

Groups 1, 2, and 3 restorations showed good survival times after 5 years in function, whereas group 4 presented the worst survival times. Group 2 restorations showed the highest amount of necessary aftercare measures.

CLINICAL RELEVANCE

The current investigation shows that groups 1, 2, and 3 restorations should be preferred in the prosthetic treatment planning of patients with head and neck tumors. A treatment with group 4 restorations should only be considered if no other prosthetic treatment is possible or as temporary treatment.

Cirurgia Guiada para Instalação de Implantes em Paciente Submetido à Radioterapia em Região de Cabeça e Pescoço

Introdução: O uso dos implantes osseointegrados para reabilitação de pacientes com dificuldade de adaptação de próteses convencionais mostra-se mais frequente a cada dia. Um grande grupo candidato à reabilitação com essa modalidade são os pacientes tratados para as neoplasias de cabeça e pescoço (CP). A irradiação na região de CP pode ser limitante para a instalação de implantes, porém a literatura apresenta evidências de técnicas e planejamentos favoráveis ao procedimento nesse grupo de pacientes. As técnicas menos traumáticas para intervenções na cavidade oral devem ser avaliadas, e os guias cirúrgicos para colocação de implantes podem ser aliados nesses procedimentos. Relato do caso: Paciente do sexo feminino, 64 anos, tratada com cirurgia, quimioterapia e radioterapia em cavidade oral para um carcinoma espinocelular (CEC) em língua e, em um segundo momento, diagnosticada e tratada com cirurgia para CEC em região de rebordo alveolar maxilar esquerdo por meio de hemipalatecmia, necessitava de reabilitação com implantes osseointegrados na região onde havia sido tratada com radiação primariamente. Realizou-se a cirurgia de colocação dos implantes com a tecnologia guiada para acarretar o mínimo trauma às estruturas bucais. Conclusão: O procedimento cirúrgico foi executado com sucesso. Atualmente, aguarda-se o período de osseointegração para a posterior reabilitação protética.

Success of dental implants in patients with large bone defect and analysis of risk factors for implant failure: a non-randomized retrospective cohort study

OBJECTIVES

This study aimed to retrospectively investigate the success and survival rates of dental implants used for dentomaxillary prostheses at our hospital and the risk factors associated with large bone defects.

MATERIALS AND METHODS

A total of 138 external joint system implants used for dentomaxillary prostheses in 40 patients with large bone defects were included in this study. The alveolar bone at the site of implant insertion was evaluated using panoramic radiography and computed tomography. Various risk factors (demographic characteristics, dental status, and operative factors such as the employment of alveolar bone augmentation, the site, the length, and diameter of implants) for implant failure and complete implant loss were investigated using univariate and multivariate analyses. The associations between the variables and the success and survival rates of dental implants were analyzed using the multivariate Cox proportional hazard models.

RESULTS

The 10-year overall success and survival rates were 81.3% and 88.4% in this study. Multivariable analysis showed that the male sex (HR 6.22), shorter implants (≤ 8.5 mm) (HR 5.21), and bone augmentation (HR 2.58) were independent predictors of success rate. Bone augmentation (HR 5.14) and narrow implants (≤ 3.3 mm) (HR 3.86) were independent predictors of the survival rate.

CONCLUSION

Male sex, shorter or narrow implants, and bone augmentation were independent risk factors for dental implants used in dentomaxillary prostheses in patients with large bone defects.

CLINICAL RELEVANCE

Clinicians should consider these risk factors and pay close attention to the management of these patients.

Survival of dental implants and occurrence of osteoradionecrosis in irradiated head and neck cancer patients: a systematic review and meta-analysis

OBJECTIVES

This systematic review assesses dental implant survival, calculates the incidence rate of osteoradionecrosis, and evaluates risk factors in irradiated head and neck cancer patients.

MATERIALS AND METHODS

Various databases (e.g., Medline/Embase using Ovid) and gray literature platforms were searched using a combination of keywords and subject headings. When appropriate, meta-analysis was carried out using a random effects model. Otherwise, pooled analysis was applied.

RESULTS

A total of 425 of the 660 included patients received radiotherapy. In total, 2602 dental implants were placed, and 1637 were placed in irradiated patients. Implant survival after an average follow-up of 37.7 months was 97% (5% confidence interval, CI 95.2%, 95% CI 98.3%) in nonirradiated patients and 91.9% (5% CI 87.7%, 95% CI: 95.3%) after an average follow-up of 39.8 months in irradiated patients. Osteoradionecrosis occurred in 11 cases, leading to an incidence of 3% (5% CI 1.6%, 95% CI 4.9%). The main factors impacting implant survival were radiation and grafting status, while factors influencing osteoradionecrosis could not be determined using meta-analysis.

CONCLUSION

Our data show that implant survival in irradiated patients is lower than in nonirradiated patients, and osteoradionecrosis is-while rare-a serious complication that any OMF surgeon should be prepared for. The key to success could be a standardized patient selection and therapy to improve the standard of care, reduce risks and shorten treatment time.

CLINICAL RELEVANCE

Our analysis provides further evidence that implant placement is a feasible treatment option in irradiated head and neck cancer patients with diminished oral function and good long-term cancer prognosis.

Segmental mandibular reconstruction in patients with poor lower extremity perfusion, vessel-depleted necks and/or profound medical frailty

PURPOSE OF REVIEW

Options for segmental mandibular reconstruction in patients poorly suited to undergo fibula free flap (FFF).

RECENT FINDINGS

Although FFF is the current 'gold standard' for segmental mandibular reconstruction, other reconstructive options must be considered when FFF is contraindicated or disfavoured and/or patient frailty precludes a lengthy anaesthetic. In addition to various nonvascularized and soft tissue only reconstructions, excellent osseous free flap alternatives for functional segmental mandibular reconstruction may be employed. The subscapular system free flaps (SSSFF) may be ideal in frail and/or elderly patients, as SSSFF allows for early mobility and does not alter gait. In extensive and/or symphyseal defects, functional mandibular reconstruction in lieu of a free flap is extremely limited. Pedicled segmental mandibular reconstructions remain reasonable options, but limited contemporary literature highlights unpredictable bone graft perfusion and poor long-term functional outcomes.

SUMMARY

There are several excellent free flap alternatives to FFF in segmental mandibular reconstruction, assuming adequate cervical recipient vessels are present. On the basis of the current literature, the optimal mandibular reconstruction for the medically frail, elderly and/or patients with extreme vessel-depleted necks is limited and debatable. In qualifying (i.e. limited, lateral) defects, soft tissue only reconstructions should be strongly considered when osseous free flaps are unavailable.

Osseointegrated implant survival, success and prosthodontic outcomes in composite free flaps: A 10-year retrospective cohort study

OBJECTIVES

To evaluate implant survival, success and prosthodontic outcomes in a variety of composite free flaps.

MATERIAL AND METHODS

A retrospective analysis of patient records was used for data collection of implants placed into flaps. Free flap donor sites included fibula, iliac crest, scapula, medial femoral condyle and radial forearm. Kaplan-Meier survival curves were used to estimate survival. Cox regression was used to assess variables affecting survival, and binary logistic regression was utilised to determine effect of variables on prosthodontic outcomes.

RESULTS

There were 150 implants placed into 45 fibula, 98 implants into 29 iliac crest, 62 implants into 22 scapula, 6 implants into 3 medial femoral condyle and 2 implants in radial forearm composite free flaps. There was no difference in survival or success between or within the various flaps. Active smoking, increasing age, male gender and radiotherapy were associated with implant failure. Of patients completing prosthodontic rehabilitation, 93% were successful. There was no difference in likelihood of failure between different flap types. Fixed implant-supported dentures were associated with poor oral hygiene compared with removable designs (OR2.9, 95%CI 1.1-7.8, p = .03).

CONCLUSIONS

There is adequate survival and success of implants in common flaps. Caution is required when planning implants in patients exposed to radiotherapy and smokers. Ability to maintain adequate oral hygiene is an important prosthetic design consideration.

Clinical long-term and patient-reported outcomes of dental implants in oral cancer patients

BACKGROUND AND PURPOSE

The aim of this clinical study was to investigate the clinical long-term and patient-reported outcome of dental implants in patients with oral cancer. In addition, analysis of the influence of radiation therapy, timing of implant insertion, and augmentation procedures on implant survival was performed.

MATERIAL AND METHODS

This retrospective study investigated the clinical outcome of 711 dental implants in 164 oral cancer patients, inserted by experienced surgeons of the Department of Oral and Maxillofacial Surgery, University Medical Center Mainz, Germany. Oral health-related quality of life (OHRQoL) was evaluated.

RESULTS

Cumulative 5-year and 10-year implant survival rates for all included implants were 87.3% and 80.0%. Implants placed straight after ablative surgery (primary implant placement) and implants placed after completing the oncologic treatment (secondary implant placement) showed a comparable implant survival (92.5% vs. 89.5%; p = 0.635). Irradiation therapy had no significant influence on implant survival of secondary placed implants (p = 0.929). However, regarding implant site (native bone vs. augmented bone) and radiation therapy (non-irradiated bone vs. irradiated bone), implants inserted in irradiated bone that received augmentation procedures showed a statistically significant lower implant survival (p < 0.001). Patients reported a distinct improvement in OHRQoL.

CONCLUSIONS

Promising long-term survival rates of dental implants in patients after treatment of oral cancer were seen. In addition, patients benefit in form of an improved OHRQoL. However, bone augmentation procedures in irradiated bone may result in an impaired implants' prognosis.

Significance of site-specific radiation dose and technique for success of implant-based prosthetic rehabilitation in irradiated head and neck cancer patients-A cohort study

BACKGROUND

Radiotherapy aggravates implant-based prosthetic rehabilitation in patients with head and neck cancer.

PURPOSE

To evaluate the impact of radiation dose at implant and parotid gland site for prosthetic rehabilitation.

MATERIAL AND METHODS

The retrospective study includes 121 irradiated head and neck cancer patients with 751 inserted implants. Radiation doses on implant bed and parotid gland site were recorded by 3-dimensional modulated radiation plans. Implant success was clinically and radiographically evaluated according to modified Albrektsson criteria and compared to treatment- and patient-specific data.

RESULTS

Implant overall survival after 5 years was 92.4% with an implant success rate of 74.9%. Main reasons for implant failure were marginal bone resorption (20.9%), implant not in situ or unloaded (9.6%) and peri-implantitis (7.5%). A mean radiation dose of 62.6 Gy was applied with a mean parotid dose of 35 Gy. Modulating radiation techniques went along with lower grades of xerostomia (p < 0.001). At implant site mean doses of 57.5, 42.0, and 32.3 Gy were recorded for oral, oropharyngeal, and hypopharyngeal/laryngeal carcinoma, respectively. Implant success inversely correlated to radiation dose at implant site. Strong predictors for implant failure in uni- and multivariate analysis were implant-specific dose >50 Gy (HR 7.9), parotid dose >30 Gy (HR 2.3), bone (HR 14.5) and soft tissue (HR 4.5) transplants, bad oral hygiene (HR 3.8), nonmodulated radiation treatment planning (HR 14.5), and nontelescopic prosthetics (HR 5.2).

CONCLUSION

Radiotherapy impedes implant success in a dose-dependent manner at implant site. Modern radiation techniques effectively reduce xerostomia favoring implant-based prosthetic rehabilitation. Implantation in bone grafts is more critical and telescopic-retained overdentures should be preferred.

Long-term outcomes of implant-based dental rehabilitation in head and neck cancer patients after reconstruction with the free vascularized fibula flap

The study aimed at evaluating, comprehensively, implant-based dental rehabilitation in head and neck cancer patients after maxillofacial reconstruction with a vascularized free fibula flap (FFF). Data were obtained by retrospectively reviewing the medical records of patients treated in Amsterdam UMC-VU Medical Center. Dental implant survival and implant success according to the Albrektsson criteria were analyzed. Additionally, prosthetic-related outcomes were studied, with a focus on functional dental rehabilitation. In total, 161 implants were placed in FFFs, with a mean follow-up of 4.9 years (range 0.2-23.4). Implant survival was 55.3% in irradiated FFFs and 96% in non-irradiated FFFs. Significant predictors for implant failure were tobacco use and irradiation of the FFF. Implant success was 40.4% in irradiated FFFs and 61.4% in non-irradiated FFFs, mainly due to implant failure and non-functional implants. Implant-based dental rehabilitation was started 45 times in 42 patients, out of 161 FFF reconstructions (27.9%). Thirty-seven patients completed the dental rehabilitation, 29 of whom achieved functional rehabilitation. Irradiation of the FFF negatively influenced attainment of functional rehabilitation. For patients with functional rehabilitation, the body mass index varied at different timepoints: FFF reconstruction, 24.6; dental implantation 23.5; and after placing dental prosthesis, 23.9. Functional implant-based dental rehabilitation, if started, can be achieved in the majority of head and neck cancer patients after FFF reconstruction. Actively smoking patients with an irradiated FFF should be clearly informed about the increased risk for implant and prosthetic treatment failure.

Outcomes of osseointegrated implants in patients with benign and malignant pathologies of the head and neck: a 10-year single-centre study

The surgical management of head and neck pathologies involving the maxilla and mandible results in significant functional and aesthetic deficits, and ultimately reduced quality of life. Composite free flaps used for reconstruction address many of these deficits and create a foundation for the use of osseointegrated implants to support prosthetic replacement of the dentition. There are few comparative studies examining outcomes of implants in native and reconstructed bone in head and neck cancer patients. The aim of this retrospective cohort study was to compare survival rates and the effects of risk factors between implants placed in native and reconstructed bone. The Kaplan-Meier method estimated cumulative 1- and 5-year implant survival rates of 99.5% and 95% for native bone and 96% and 88% for reconstructed bone. Multivariate Cox regression found an increased risk of implant failure in reconstructed bone (hazard ratio (HR) 9.9, 95% confidence interval (CI) 3.4-29.7, P<0.001). Subgroup analysis of the cohorts found an increased risk of failure in the reconstructed group associated with radiotherapy (HR 6.4, 95% CI 1.8-22.3, P=0.004), current smoking (HR 23.2, 95% CI 2.7-198.6, P=0.004), and previous smoking (HR 9.0, 95% CI 1.1-71.9, P=0.038). There was no effect in the native bone group. Implants placed into reconstructed bone had higher rates of failure, and smoking status and radiotherapy increased the risk of implant failure.

Immediate implant placement in edentulous oral cancer patients: a long-term retrospective analysis of 207 patients

Although the functional benefits of implants in the rehabilitation of edentulous cancer patients are well-known, most studies report on postponed implant placement. The outcome of immediate implant placement regarding successful rehabilitation, implant loading and survival is unclear. Two hundred and seven edentulous oral cancer patients that received implants during ablative surgery at the Radboud University Medical Centre between 2000 and 2011 were included. Data regarding the oncological treatment, implant placement, follow-up and prosthodontic rehabilitation were recorded retrospectively with a follow-up period of 5-17 years. Functioning implant-retained dentures were made in 73.9% of the patients. Of the surviving patients, 81.9% had functioning dentures after 2 years and 86.3% after 10 years. Patients with ASA score 1 and younger patients were rehabilitated more frequently. The median time of functioning denture placement was 336 days after surgery, with a negative influence of postoperative radiotherapy. Implant survival was 90.7%, and was lower when the implant was placed in a jaw involved in the tumour. Immediate implant placement during oral cancer surgery led to a high number of edentulous patients rehabilitated with implant-retained dentures, which are placed at an early time.

Epidemiological profile and clinical implications of oral squamous cell carcinoma adjacent to dental implants

OBJECTIVES

Describe the epidemiological profile of patients with oral squamous cell carcinoma (OSCC) around dental implants (DI), investigate the spectrum of clinical and pathological characteristics, and discuss the implications of diagnosis delay of these lesions.

METHODS

Retrospective analysis of patients treated of OSCC adjacent to DI at A.C. Camargo Cancer Center between 2009 and 2020.

RESULTS

Thirty one patients were identified, being women the majority (58.1%). The mean age of the patients was 68.8 years. Never smoker corresponds to 46.9% and never alcohol consumer to 54.9% of the sample. OPMD was reported in 45.2% of patients, affecting mainly women (78.5%). Leukoplakia (63.7%) followed by oral lichen planus (36.3%) was the most common OPMD found in women. OSCC adjacent to DI occurred in the inferior gingiva/alveolar mucosa in 48.3% of cases, and ulceration was the most common clinical appearance (87%). Peri-implantitis (PI) was initial clinical diagnosis in 16.1% of cases.

CONCLUSIONS

Oral squamous cell carcinoma adjacent to DI was more common in women over 70 years old, non-smokers and non-drinker, and the majority had oral leukoplakia before the diagnosis of OSCC. OSCC may present clinical and radiographic features that resemble PI which can delay the diagnosis and impair the prognosis.

Dental Implant Survival in Vascularized Bone Flaps: A Systematic Review and Meta-Analysis

BACKGROUND

Maxillofacial reconstruction with vascularized bone restores facial contour and provides structural support and a foundation for dental rehabilitation. Routine implant placement in such cases, however, remains uncommon. This study aims to determine dental implant survival in patients undergoing vascularized maxillary or mandibular reconstruction through a systematic review of the literature.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the literature was queried for implant placement in reconstructed jaws using Medical Subject Headings terms on PubMed, Embase, and Cochrane platforms. Weighted implant survivals were calculated for the entire cohort and subcohorts stratified by radiotherapy. Meta-analyses were performed to estimate effect of radiation on implant osseointegration.

RESULTS

Of 3965 publications identified, 42 were reviewed, including 1084 patients with 3636 dental implants. Weighted implant survival was 92.2 percent at a median follow-up of 36 months. Survival was 97.0 percent in 269 implants placed immediately in 60 patients versus 89.9 percent in 1897 delayed implants placed in 597 patients, with follow-up of 14 and 40 months, respectively. Dental implants without radiotherapy exposure had better survival than those exposed to radiation (95.3 versus 84.6 percent; p < 0.01) at a median follow-up of 36 months. Meta-analyses showed that radiation significantly increased the risk of implant failure (risk ratio, 4.74; p < 0.01) and suggested that implants placed before radiotherapy trended toward better survival (88.9 percent versus 83.4 percent, p = 0.07; risk ratio, 0.52; p = 0.14).

CONCLUSIONS

Overall implant survival was 92.2 percent; however, radiotherapy adversely impacted outcomes. Implants placed before radiotherapy may demonstrate superior survival than implants placed after.

Systematic review and pooled analysis of survival rates, success, and outcomes of osseointegrated implants in a variety of composite free flaps

The aim of this review was to provide an update on survival rates of osseointegrated implants into common composite free flaps used for maxillary and mandibular reconstructions and identify factors affecting outcomes. PubMed, Medline, Embase, and Cochrane databases were searched. Included studies reported implant survival by flap type. Results were pooled and survival was estimated with the Kaplan-Meier method. Variables affecting survival were assessed using Cox regression. Thirty-two of the 2631 articles retrieved were included, totaling 2626 implants placed into fibula, iliac crest, scapula, and radial forearm free flaps. Pooled survival showed 94% 5-year survival of implants in fibula and iliac crest with no difference between groups (P = .3). Factors effecting survival included radiotherapy (HR 2.3, 95% CI 1.2-4.6, P = .027) and malignant disease (HR 2.2, 95%CI 1.6-3.1, P < .001). Implant survival appears adequate across common flap types; however, there are limited numbers reported in less common flaps.

Hyperbaric oxygen therapy for the placement of dental implants in irradiated patients: systematic review and meta-analysis

This study was a systematic review with meta-analysis to evaluate the influence of hyperbaric oxygen therapy (HBOT) on the survival of dental implants placed in patients who had had radiotherapy for cancer of the head and neck. A systematic literature search was conducted using the PubMed/Medline, Science Direct, Embase and the Cochrane Library, between January 1985 and July 2018. The study observed the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analysis) declaration and norms, and the systematic review was duly recorded in the PROSPERO (International prospective register of systematic reviews) database. Inclusion and exclusion criteria were applied, and all articles were selected on the basis of PICO questions. The process of eligibility and quality evaluation yielded three studies for statistical analysis. Based on the survival rates, there was no evidence that the risk of an implant failing was different between the patients who received HBOT and those who did not. Moreover, the risk of an implant failing did not depend on the anatomical site. HBOT exerted no beneficial influence on the survival rates of implants placed in irradiated patients, and the risk of an implant failing did not depend on its location.

Oral Rehabilitation in Irradiated Patients: Implant- or Tooth-Supported Fixed Prosthesis? A Clinical Report

Cranial radiotherapy has several side effects. One of the most important complications is radiation caries that endangers the treatment prognosis. In the literature, the use of crowns and bridges for irradiated patients has been suggested as a contraindication. In addition, due to the risk of osteoradionecrosis (ORN), there are doubts about tooth extraction and implant placement. Here, we present a treatment sequence and recalls for an irradiated young patient. For irradiated patients, it is recommended to replace teeth with implants when there is no possibility for supragingival prosthetic margin.

Hyberbaric oxygen and bone reconstruction

INTRODUCTION

The aim of this literature review was to determine the benefits of hyperbaric oxygen therapy after bone reconstruction procedures in humans and identify information that may be useful for the development of optimal protocols for hyperbaric oxygen therapy to stimulate bone healing.

EVIDENCE ACQUISITION

We searched the electronic database PubMed/Medline for studies published between January 1999 and December 2018, using the key words: "bone" or "bone graft" and "mandible reconstruction" or "jaw reconstruction" and "hyperbaric oxygen" or "HBO." First, the titles and abstracts of the studies found were evaluated and those that corresponded to the aims of this review were pre-selected for analysis of the full text. Subsequently, the full texts were analyzed, and those that met the eligibility criteria were pre-selected for the review. The full texts of studies whose abstracts did not provide enough data for decision were also evaluated. Two examiners independently assessed eligibility, risk of bias and extracted data.

EVIDENCE SYNTHESIS

A total of 2237 studies were found according to pre-established criteria for data collection, of which only 5 studies were included in this systematic review. Although we observed positive results in the included studies, there are still few standardized clinical studies in the literature, assessing hyperbaric oxygen therapy after extensive bone reconstructive procedures.

CONCLUSIONS

It is difficult to compare results found in different studies due to the variety of methodological and clinical conditions assessed.

Peri implant bone resorption on microvascular free fibula flap: a radiographic retrospective study

Introduction: As the vascularization of the microvascular free fibula flap enables to maintain an osteogenic potential, osseointegrated implants have a 86% to 99% success rate. Thus, only few studies consider peri-implant bone resorption (PIBR). The aim of the study was to radiologically evaluate PIBR on fibula flaps. Materials and methods: Data were retrospectively collected. Gender, age, reason for interruptive mandibulectomy, previous radiotherapy, number of implants placed on the reconstruction, length and number of segments of the reconstruction, height of resorption were collected for each patient. Measurements were made on panoramic radiograph. Results: 85 clinical reports were reviewed for 39 retained. Peri-implant bone resorption was observed in 21 (53.9%) patients. The average age of the resorption group was 55.4 . All of the 5 patients with 4 or 5 implants on their reconstruction did not developed PIBR. 59.1% of patients with 1 segment reconstruction developed PIBR, 54.6% with 2 segments and 33.3% with 3 segments. Discussion: Age and poor oral hygiene appeared to be clearly more related to PIBR. An important number of implant (4 or 5) and a reconstruction with more than 1 segment seemed to decrease PIBR. Further studies are required to confirm these hypotheses.

Ability to Propose Optimal Prosthetic Rehabilitation can be Improved by Discussion between the Dentist and Radiation Oncologist Regarding Upstream Dosimetry

Objective Improvement of dental rehabilitation for patients who have undergone radiation therapy requires knowledge of the dose in the maxillary and mandible bones.

Materials and Methods Forty-three patients with head and neck cancers underwent evaluation for dental rehabilitation before radiation treatment dosimetry. The delivered dose to the maxilla and mandible was determined. From the dose data in the literature, three levels of risk of implant failure were defined. According to the delivered doses, the authors calculated the percentage of patients who could be fully rehabilitated with an implant, as proposed by the dentist before radiation planning.

Results Before dosimetry calculation, all of the completely edentulous arches and 94 partially edentulous (PESs) sextants could be optimally rehabilitated. After dose calculation, among the 14 arches of 7 patients who were completely edentulous, according to the mean and maximal delivered doses, 11 arches (78.6%) and 7 arches (50%) could receive an optimal prosthesis, respectively. For the three patients, who were PESs but with one arch that was completely edentulous, according to the mean and maximal delivered doses, one arch for each dose condition could receive an optimal prosthesis. Among the 94 PESs sextants, according to the mean and maximal delivered doses, 41 (43.6%) and 24 (25.5%) sextants could receive an optimal prosthesis, respectively.

Conclusion By determining the sites of implantation before dosimetry, the radiation oncologist could shield specified areas, potentially improving the possibilities for dental rehabilitation. The dialogue between the dentist and the radiation oncologist can improve the possibilities for implants and decrease the risk of unsafe implantation.

Outcomes of implant-based oral rehabilitation in head and neck oncology patients-a retrospective evaluation of a large, single regional service cohort

Background

The study reports on implant survival outcomes in head and neck cancer patients who received implant-based oral rehabilitation in a regional service centre.

Methods

A retrospective analysis of implant survival outcomes in patients treated in a regional service from 2012 to 2017 was performed. The primary outcome measure was implant survival. The secondary outcome measure was to assess the effect of covariates associated with implant failure including bone type, radiotherapy, chemotherapy, gender and surgical implant complications. Kaplan-Meier survival curves were applied to compare differences in the survival rates of groups of variables. Cox proportional hazards models were applied to identify covariates associated with implant failure. p value was set at 0.05.

Results

The sample was composed of 167 head and neck cancer patients who had 779 dental implants placed. Implant survival estimates were calculated: 3 years, 95.7% [95%CI 94.3–97.2%] and 5 years, 95.5% [95%CI 93.9–97.0%], with a median follow-up of 38 months. Gender (p = 0.09), radiotherapy (p = 0.16) and chemotherapy (p = 0.17) did not significantly influence implant survival, whereas implant failure was higher in transported (reconstructed) bone sites in comparison with native bone (p < 0.01).

Conclusion

The result of this study suggests that overall implant survival as part of the routine oral rehabilitation is high in this patient cohort; however, implant failure was found to be statistically higher for implant placed into transported bone in comparison to native bone.

Oral rehabilitation for patients with marginal and segmental mandibulectomy: A retrospective review of 111 mandibular resection prostheses

STATEMENT OF PROBLEM

Treatment and timing considerations for patients seeking oral rehabilitation after marginal or segmental mandibulectomy (with osseous reconstruction) are not well understood.

PURPOSE

The purpose of this retrospective review study was to report the type and timing of oral rehabilitation for mandibular defects without discontinuity and to describe additional treatment considerations for rehabilitation.

MATERIAL AND METHODS

The records were reviewed of all patients who received a mandibular resection prosthesis after marginal mandibulectomy, marginal mandibulectomy with fasciocutaneous free-flap reconstruction, and segmental mandibulectomy with fibula free-flap reconstruction between 2000 and 2017 in the tertiary cancer care institution. Patients not treated by the Dental Service in the institution were excluded. The specific type of rehabilitation was noted, as was the time interval between primary surgery and prosthesis delivery.

RESULTS

During the study period, 111 consecutive patients were treated by the Memorial Sloan Kettering Cancer Center Dental Service for mandibular rehabilitation. Forty-three patients underwent marginal mandibulectomy, 9 patients underwent marginal mandibulectomy with fasciocutaneous free-flap reconstruction, and 59 patients underwent segmental mandibulectomy with fibula free-flap reconstruction. Most patients in all 3 groups received mandibular resection prostheses without the use of endosseous implants. Only 4 (8%) patients who had undergone marginal mandibulectomy underwent endosseous implant placement, all of which followed marginal mandibulectomy in anterior mandibular segments without free-flap reconstruction. Patients who underwent marginal mandibulectomy with fasciocutaneous free-flap reconstruction were only restored with removable mandibular resection prostheses, and none had endosseous implants. In patients who underwent segmental mandibulectomy, 13 (22%) were rehabilitated with endosseous implants. The majority in this cohort (>50%) received radiation therapy as part of their treatment. The median time to oral rehabilitation was 8 months after marginal mandibulectomy, 14 months after marginal mandibulectomy with fasciocutaneous free-flap reconstruction, and 12 months after segmental mandibulectomy with fibula free-flap reconstruction.

CONCLUSIONS

Timing for oral rehabilitation may differ depending on the treatment modality followed for mandibular tumors in the patient with oral cancer. However, most patients in this cohort underwent rehabilitation with removable mandibular resection prostheses regardless of the timing of care. Endosseous implants were used infrequently, but research is needed to better understand their potential role and indication in the patient with oral cancer.

A Comparison of Immediate and Delayed Dental Implant Placement in Head and Neck Surgery Patients

PURPOSE

Implant-supported dental prostheses offer numerous benefits for patients after ablative procedures of the head and neck region, including restoration of function, improved self-esteem and body satisfaction, and overall quality of life. Increased experience is emerging with immediate placement of implants at the time of ablative surgery compared with the traditional delayed approach. The authors sought to identify variables affecting survival of osseointegrated dental implants in such patients and to assess the impact of timing of implant insertion (immediate vs delayed) on the time until final prosthesis insertion.

MATERIALS AND METHODS

Implant survival was assessed based on different factors: immediate versus delayed implants, benign versus malignant disease, postoperative radiotherapy, smoking status, alcohol status, age, 1- versus 2-stage surgery, hyperbaric oxygen therapy, and implant placement into native bone versus into osseous free flap reconstruction. Time to final prosthesis insertion was compared between immediate and delayed implant placement.

RESULTS

The study included 20 patients who received a total of 102 implants (39 immediate, 63 delayed). There were 7 failed implants (overall survival, 93.14%). There was no statistically relevant difference in implant survival between any of the groups assessed. However, there was a significant decrease in time to final prosthesis insertion for those patients receiving immediate implants compared with those who underwent delayed implant placement (321 days; standard error, 46.5 vs 726 days; standard error, 45 days; P < .0001).

CONCLUSIONS

Immediate implant placement is an effective approach to the prosthetic rehabilitation of patients undergoing ablative procedures of the jaws, which shortens time to final prosthesis placement without adversely affecting overall implant survival.

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.

Masticatory efficiency of implant-supported removable partial dental prostheses in patients with free fibula flap reconstructed mandibles: A split-mouth, observational study

OBJECTIVES

The aim of this split-mouth study was to evaluate the masticatory efficiency in patients with segmentally reconstructed mandibles using free fibula flaps, with and without stabilizing osteosynthesis material in-situ during implant placement for rehabilitation with implant-supported removable partial dental prostheses (ISRPDPs).

METHODS

Ten participants (n = 10; ♀ = 2, ♂ = 8; mean age = 38.1 years) consented to participate in this study. The participants' normal side (Side N) of the mandible served as the control side, for comparing the masticatory efficiency of the segmentally reconstructed and rehabilitated side (Side R). Masticatory efficiency was evaluated using the two-colored chewing gum test, measured as subjective assessment (SA) and electronically evaluated variance of hue (VOH). Data were checked for normal distribution and statistically analyzed with the level of significance set to p < 0.05.

RESULTS

Thirty-four tissue-level implants were placed in reconstructed mandibles of 10 participants. There was no significant difference observed in the masticatory efficiencies between Side N and Side R, in both subjective and electronic assessments. No implant loss was observed after a post-rehabilitated mean follow-up period of 42.7 months, revealing an implant survival rate of 100%.

CONCLUSIONS

In patients with surgically reconstructed mandibles, a normal masticatory function can be successfully achieved with a rehabilitation of the reconstructed side with implant-supported removable partial dental prostheses. Implant-supported prostheses should be actively advocated in patients with reconstructive surgeries to restore their masticatory function, extend their food choices, and improve their overall oral health-related quality of life.

Continuity defects of the mandible: Comparison of three techniques for osseous reconstruction and their impact on implant loading

Computer-aided design/manufacturing (CAD/CAM) is now widely used, but whether it can help to overcome complications in mandibular reconstruction and accelerate dental implantation is still a matter for debate. Therefore, we aimed to evaluate the benefits of this technique using vascularized iliac crest or fibula flaps in mandibular reconstruction, with respect to the time between reconstruction and implantation, and the ratio of planned to inserted implants. We reviewed retrospectively the records of 54 patients who underwent mandibular reconstructions between 2012 and 2016, and included in our study the last 10 cases representing each of the following groups: iliac crest flap with CAD/CAM (Group 1); fibula flap with CAD/CAM (Group 2); and fibula flap without CAD/CAM (Group 3). Groups 1 (p = 0.045) and 2 (p = 0.034) showed significantly shorter delays when compared with Group 3. Significant differences in average counts of implants placed were also found between Group 1 and Groups 2 (p = 0.04) and 3 (p = 0.019). The ratio of planned to placed implants was highest in Group 1. The observed differences between Group 1 and Groups 2 (p = 0.04) and 3 (p = 0.019) were significant. Our results indicate an accelerating effect of CAD/CAM on graft consolidation and dental rehabilitation.

Implant retention systems for implant-retained overdentures

Implant retained overdentures are being increasingly utilised in both general and specialist practice to rehabilitate patients with missing teeth, particularly those that are edentate. This article aims to inform the reader of a variety of retention systems that are available to retain an implant overdenture and to understand how these systems work, their advantages and disadvantages and to outline some of the clinical and treatment planning considerations involved in selecting the most appropriate retention system for patients.

HOPON (Hyperbaric Oxygen for the Prevention of Osteoradionecrosis): a randomised controlled trial of hyperbaric oxygen to prevent osteoradionecrosis of the irradiated mandible: study protocol for a randomised controlled trial

BACKGROUND

Osteoradionecrosis of the mandible is the most common serious complication of radiotherapy for head and neck malignancy. For decades, hyperbaric oxygen has been employed in efforts to prevent those cases of osteoradionecrosis that are precipitated by dental extractions or implant placement. The evidence for using hyperbaric oxygen remains poor and current clinical practice varies greatly. We describe a protocol for a clinical trial to assess the benefit of hyperbaric oxygen in the prevention of osteoradionecrosis during surgery on the irradiated mandible.

METHODS/DESIGN

The HOPON trial is a phase III, randomised controlled, multi-centre trial. It employs an unblinded trial design, but the assessment of the primary endpoint, i.e. the diagnosis of osteoradionecrosis, is assessed on anonymised clinical photographs and radiographs by a blinded expert panel. Eligibility is through the need for a high-risk dental procedure in the mandible where at least 50-Gy radiotherapy has been received. Patients are randomised 1:1 to hyperbaric oxygen arm (Marx protocol) : control arm, but both groups receive antibiotics and chlorhexidine mouthwash. The primary endpoint is the presence of osteoradionecrosis at 6 months following surgery, but secondary endpoints include other time points, acute symptoms and pain, quality of life, and where implants are placed, their successful retention.

DISCUSSION

The protocol presented has evolved through feasibility stages and through analysis of interim data. The classification of osteoradionecrosis has undergone technical refinement to ensure that robust definitions are employed. The HOPON trial is the only multi-centre RCT conducted in this clinical setting despite decades of use of hyperbaric oxygen for the prevention of osteoradionecrosis.

TRIAL REGISTRATION

European Clinical Trials Database, ID: EudraCT200700622527 . First registered on 5 November 2007.