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

A study on the morphology of iliac crest based on the objectives of jaw bone defect reconstruction

OBJECTIVES

to understand the morphological characteristics of iliac crest and provide advice and assistance for jaw bone reconstruction with iliac bone flap by evaluating the thickness and curvature of iliac crest.

MATERIALS AND METHODS

100 patients who had taken Spiral CT of the Abdominal region before surgeries between 2020 and 2022 were included in this study. 3D reconstruction images of the iliac bones were created. 5 vertical planes perpendicular to the iliac crest were made every 2 cm along the centerline of the iliac crest (VP2 ~ VP10). On these vertical planes, 4 perpendicular lines were made every 1 cm along the long axis of the iliac crest (D1 ~ D4). The thicknesses at these sites, horizontal angle (HA) of iliac crest and the distance between inflection point and the central point of anterior superior iliac spine (DIA) were measured.

RESULTS

The thickness of iliac bone decreased significantly from D1 ~ D4 on VP6 ~ VP10 and from VP2 ~ VP10 on D3 and D4 level (P<0.05). HA of iliac crests was 149.13 ± 6.92°, and DIA was 7.36 ± 1.01 cm. Iliac bone thickness, HA and DIA had very weak or weak correlation with patient's age, height and weight.

CONCLUSIONS

The average thicknesses of iliac crest were decreased approximately from front to back, from top to bottom. The thickness and curvature of the iliac crest were difficult to predict by age, height and weight.

CLINICAL RELEVANCE

Virtual surgical planning is recommended before jaw bone reconstruction surgery with iliac bone flap, and iliac crest process towards alveolar process might be a better choice.

Reconstructive flap surgery in head and neck cancer patients: an interdisciplinary view of the challenges encountered by radiation oncologists in postoperative radiotherapy

Background

Major advances have been made in reconstructive surgery in the last decades to reduce morbidity in head and neck cancer. Flaps are now present in 80% of patients with oral cavity cancer to cover anatomic, functional, and cosmetic needs. However, gaps in interdisciplinary innovation transfer from surgery to postoperative radiotherapy (poRT) remain challenging. We aimed to provide an interdisciplinary view of the challenges encountered by radiation oncologists in planning head and neck postoperative radiotherapy.

Methods

A systematic and critical review was conducted to address areas of optimization in surgery and radiology that may be relevant to poRT.

Results

Despite extensive surgical literature on flap techniques and salvage surgery, 13 retrospective series were identified, where flap outcomes were indirectly compared between surgery alone or poRT. These low-evidence studies suggest that radiotherapy accelerates flap atrophy, fibrosis, and osteoradionecrosis and deteriorates functional outcomes. Preliminary evidence suggests that tumor spread occurs at the flap-tissue junction rather than in the flaps. One prospective 15-patient study showed 31.3% vs. 39.2% flap volume reduction without or with poRT. In an international consensus, experts recognized the needs for optimized flap-sparing poRT against flap-related functional deterioration and bone damage. CT, MRI, and PET-CT modalities show potential for the delineation of the junction area between native tissues and flap for flap segmentation and to characterize flap-specific changes quantitatively and correlate them with patterns of relapse or complications.

Conclusion

Flap management in poRT is insufficiently documented, but poRT seems to damage flaps. Current gaps in knowledge underscore the need for prospective flap assessment and interdisciplinary trials investigating flap morbidity minimization by flap-sparing poRT planning.

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.

Digitally designed stent-assisted soft-tissue management after jaw reconstruction: a prospective cohort study

OBJECTIVES

A digitally designed stent was invented to assist vestibuloplasty and free gingival graft (FGG) after jaw reconstruction. This study aimed to compare the effects of conventional soft-tissue management comprising vestibuloplasty combined with FGG and modified soft-tissue management using a digitally designed stent on the vestibular sulcus depth (VD), keratinised-tissue width (KTW) and peri-implant tissue health in patients undergoing jaw reconstruction.

MATERIALS AND METHODS

This prospective cohort study enrolled patients who underwent jaw reconstruction using a fibular flap, iliac flap, or onlay bone graft followed by implant-supported rehabilitation at the Peking University School and Hospital of Stomatology between May 2019 and July 2022. Patients in the stent group received digitally designed stents following vestibuloplasty combined with FGG for peri-implant soft-tissue management. Patients in the control group underwent a conventional vestibuloplasty combined with FGG. VD and KTW were evaluated immediately after implant loading (T2) and 1 year after implant loading (T3), and the atrophy rates of VD and KTW were calculated. Peri-implant clinical parameters were evaluated at T3. Comparisons between the groups were performed using the Mann-Whitney U test. The effects of age, sex, primary disease, reconstruction type, reconstructed jaw and the number and location of implants on VD and KTW were evaluated using linear regression analysis.

RESULTS

There were no significant differences in the atrophy rates of VD and KTW between the stent and control groups at T2 and T3 (both P ≥ 0.05). There were no significant differences in peri-implant clinical parameters between the stent and control groups at T3 (P ≥ 0.05). Reconstruction type, location of implants and primary disease influenced VD, and reconstruction type and age influenced KTW.

CONCLUSIONS

There was no significant difference in the maintenance of VD and KTW after jaw reconstruction between soft-tissue management using a digitally designed stent and the conventional method. Further, digitally designed stents do not affect peri-implant tissue health.

CLINICAL RELEVANCE

Digitally designed stents can simplify clinical procedures without adverse effects on peri-implant tissue health, but they do not promote keratinized mucosa augmentation and vestibuloplasty.

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.

The dental management of patients irradiated for head and neck cancer

Patients undergoing radiotherapy for head and neck cancers are prone to a range of dental complications, including mucositis, trismus, xerostomia, radiation caries and osteoradionecrosis. Specific considerations include the preventive, restorative and rehabilitative management of such patients, and the prevention and treatment of complications. This article aims to highlight the current understanding and management of dental needs for patients who have had or will undergo radiotherapy.

Bone resorption after maxillary reconstruction with the vascularized free iliac flap

The aim of this study was to evaluate the resorption of the iliac bone after maxillary reconstruction with a vascularized free iliac flap. Twenty-seven patients with maxillary defects who underwent maxillary reconstruction with the vascularized free iliac flap between January 2017 and January 2021 were included. Computed tomography (CT) images taken at 1 week, approximately 6 months, and 1 year after the surgery were used for evaluation. The total iliac bone thickness and height, cortical bone thickness, and cancellous bone density were measured in the CT images. Compared with 1 week after the surgery, the total thickness and height of the iliac bone were reduced significantly 1 year after the surgery, and the cortical bone thickness and cancellous bone density were reduced significantly at 6 months and 1 year after the surgery. Compared with 6 months after the surgery, cancellous bone density was reduced significantly 1 year after the surgery. In conclusion, during the first year after maxillary reconstruction with a vascularized free iliac flap, there was significant resorption of iliac bone, including the total iliac bone thickness and height, the cortical bone thickness, and the cancellous bone density.

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.

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

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

Retrospective Evaluation of Implants Placed in Iliac Crest Autografts and Pristine Bone

Objective: Iliac crest autografts can compensate for severe mandibular atrophy before implant placement. However, the implant success in the augmented bone is not entirely predictable. Here we performed a retrospective cohort study to determine the success and related parameters of implants placed in augmented bone and pristine bone for up to 11 years. Material and Methods: We analyzed 18 patients where 72 implants were placed six months after iliac crest transplantation and 19 patients where 76 implants were placed in pristine bone. The primary endpoint was implant loss. Secondary endpoints were the implant success, peri-implant bone loss, and the clinical parameters related to peri-implantitis. Moreover, we evaluated the oral-health-related quality of life (OHIP). Results: Within a mean follow-up of 5.8 ± 2.2 and 7.6 ± 2.8 years, six but no implants were lost when placed in augmented and pristine bone, respectively. Among those implants remaining in situ, 58% and 68% were rated as implant success (p = 0.09). A total of 11% and 16% of the implants placed in the augmented and the pristine bone were identified as peri-implantitis (p = 0.08). Bone loss was similar in both groups, with a mean of 2.95 ± 1.72 mm and 2.44 ± 0.76 mm. The mean OHIP scores were 16.36 ± 13.76 and 8.78 ± 7.21 in the augmentation and the control group, respectively (p = 0.35). Conclusions: Implants placed in iliac crest autografts have a higher risk for implant loss and lower implant success rates compared to those placed in the pristine bone.

Clinical outcomes of keratinized mucosa augmentation in jaws reconstructed with fibula or iliac bone flaps

This prospective study was undertaken to evaluate the treatment outcomes of keratinized mucosa augmentation (KMA) on the buccal and palatal/lingual sides of implants in jaws reconstructed after oncological surgery. Forty-two implants in 12 patients whose jaws had been reconstructed with a fibula or iliac bone flap were included. KMA was performed at 3 months after implant placement; this included an apically displaced partial-thickness flap and a free gingival graft (FGG) around the implants to increase the keratinized mucosa width (KMW). Patients were followed up for at least 6 months post-surgery. KMW, shrinkage, and patient pain and discomfort measured on a visual analogue scale were analysed. A histological analysis was performed of tissue epithelium from two patients. The results showed that KMW was >2 mm on both the buccal and palatal/lingual sides during follow-up. Before surgery, histological analysis showed epithelium with no epithelial spikes; normal keratinized epithelial spikes were observed at 8 weeks after KMA. Greater KMW was observed around implants in reconstructed maxillae than around those in reconstructed mandibles (P < 0.001). Patients felt more pain at the donor site than at the recipient site during the first 3 days post-surgery. KMA with FGG was predictable in reconstructed jaws and may help maintain the long-term stability of implants.

Survival of vascularized osseous flaps in mandibular reconstruction: A network meta-analysis

Objective

An evidence regarding which bony flap for reconstruction of mandibular defects following tumour resection is associated with the highest survival rate is still lacking. This network meta-analysis (NMA) aimed to guide surgeons selecting which vascularized osseous flap is associated with the highest survival rate for mandibular reconstruction.

Methods

From inception to March 2021, PubMed, Embase, Scopus, and Cochrane library were searched to identify the eligible studies. The outcome variable was the flap survival rate. The Bayesian NMA accompanied by a random effect model and 95% credible intervals (CrI) was calculated.

Results

Twenty-two studies with a total of 1513 patients, comparing four osseous flaps namely fibula free flap (FFF), deep circumferential iliac artery flap (DCIA), scapula flap, and osteocutaneous radial forearm flap (ORFF) were included. The respective survival rates of FFF, DCIA, Scapula, and ORFF were 94.50%, 93.12%, 97%, and 95.95%. The NMA failed to show a statistically significant difference between all comparators (FFF versus DCIA (Odd ratio, 1.8; CrI, 0.58,5.0); FFF versus ORFF (Odd ratio, 0.57; CrI, 0.077; 2.9); FFF versus scapula flap (Odd ratio, 0.25; CrI, 0.026; 1.5); DCIA versus ORFF (Odd ratio, 0.32; CrI, 0.037; 2.1); DCIA versus scapula flap (Odd ratio, 0.14; CrI, 0.015; 1.1) and ORFF versus scapula flap (Odd ratio, 2.3; CrI, 0.16; 34)).

Conclusion

Within the limitations of the current NMA, FFF, DCIA, Scapula, and ORFF showed a comparable survival rate for mandibular reconstruction. Although the scapula flap reported the highest survival rate compared to other osseous flaps for mandibular reconstruction; however, the decision making when choosing an osseous flap should be based on many factors rather than simply flap survival rate.

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.

Mandibular rehabilitation: From the Andy Gump deformity to jaw-in-a-day

The mandible is a critical structure of the lower facial skeleton which plays an important role in several vital functions. Segmental resection of the mandible is at times required in patients with advanced oral cavity malignancies, primary mandibular tumors, and radiation or medication induced osteonecrosis. Mandibulectomy can significantly decrease quality of life, and thus mandibular reconstruction is an important aspect of the operative plan. Mandibular reconstruction is challenging due to the complex three-dimensional anatomy of the mandible, and the precision required to restore dental occlusion in dentate patients. Significant advances have been made over the past decade in the ability to reconstruct and rehabilitate patients after a segmental mandibulectomy. This review will highlight these advances and discuss the timing of dental implantation.

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.

Retrospective long-term clinical evaluation of implant-prosthetic rehabilitations after head and neck cancer therapy

OBJECTIVE

To assess clinical and patient-reported outcomes of implant-prosthetic rehabilitations in patients with a history of head-neck cancer (HNC), treated with tumor resection without (TR) or with adjuvant radiotherapy (TR/RT). A healthy cohort rehabilitated with the same reconstructive protocols served as control group (C).

MATERIALS AND METHODS

A total of 28 women and 29 men were considered in the present retrospective study. Participants received 322 implants, finally supporting 79 prosthetic reconstructions. Primary outcome was the assessment of implant and prosthetic survival rates. Furthermore peri-implant soft tissue parameters (attached peri-implant mucosa, AM; modified bleeding and plaque indices, mBI/mPI; probing depth, PD) and prosthetic technical complications were documented. Patient-reported outcome measures (PROMs) by means of visual analog scales (VAS) and the Oral Health Impact Profile German 14 form (OHIP G14) were collected. For statistical purposes Chi-square and Mann-Whitney-U-Test were adapted.

RESULTS

After a mean follow-up of 81.2 ± 50.3 months, implant survival rate was 98.1% (HNC-TR), 98.2% (HNC-TR/RT) and 100.0% (C), respectively (four implants failed in the HNC groups). HNC-TR/RT showed significant higher mPI and mBI compared to C. Within HNC-TR/RT, vestibuloplasty significantly reduced mBI and PD values. No failures occurred at the prosthetic level. Overall, higher VAS scores were reported for bar- compared with Locator-retained prostheses. Furthermore, increased OHIP G14 values resulted for HNC-TR/RT.

CONCLUSIONS

High survival rates on implant and prosthetic level were observed. The use of soft tissue grafts resulted in stabilization of the peri-implant mucosa in irradiated patients. In terms of retention and chewing ability, participants preferred bars over Locator attachments.

"Three-in-one" patient-specific surgical guides for simultaneous dental implants in fibula flap jaw reconstruction: A prospective case series

BACKGROUND

Conventional freehand immediate placement of dental implants is technically challenging in the jaw reconstructive surgery. Computer-aided surgery might be the best solution, however, there has not been any standard approach to ensure the accuracy and efficiency of simultaneous dental implants in fibula flap jaw reconstruction.

PURPOSE

We aim to evaluate the clinical outcome of simultaneous dental implant in fibula flap using the "three-in-one" patient-specific surgical guide (3-in-1-PSSG) in an open-label, prospective, single-arm, and single-center clinical trial.

MATERIALS AND METHODS

A novel computer-aided designed and three-dimensional (3D) printed 3-in-1-PSSG, which contains functions of fibula segmentation, surgical plate positioning and implant placement, was used to facilitate the reconstructive surgery and simultaneous dental implant placement. The intraoperative success of dental implant placement, implant survival rate and accuracy of dental implant placement were reported.

RESULTS

From November 2018 to June 2020, 15 consecutive patients with 48 dental implants were enrolled in this study. Fifteen 3-in-1-PSSGs were fabricated with a mean number of dental implants per guide of 3.2 ± 1.5. The intraoperative success rate of this approach was 14 out of 15. With an average follow-up period of 40 weeks, the overall implant survival rate was 83.3% (40/48). Eight implants were removed due to two fibula flap failures. The mean deviation at the implant platform and implant apex were 2.8 mm (interquartile range [IQR]: 1.9-3.4) and 3.2 mm (IQR: 2.0-4.6), and the angular deviation was 2.5° (IQR: 1.1-6.8).

CONCLUSIONS

Our preliminary data indicated that the 3D printed 3-in-1-PSSG facilitated simultaneous dental implant in fibula flap jaw reconstruction with a favorable intraoperative success and short-term clinical outcome. It might be a viable alternative to allow one-step immediate oral rehabilitation in patients underwent jaw reconstruction with free flaps. Long-term results with a larger sample size are warranted.