Making the Case for Virtual Surgical Planning: Bilateral Sequential Fibula Flaps with Immediate Dental Implants for Maxillectomy.

SUMMARY: Oncologic maxillectomy defects requiring bony reconstruction are among the most challenging head and neck cases because of the complex three-dimensional geometry of the midface. Virtual surgical planning technology is advantageous in these cases because it provides superior positional precision and accuracy compared with traditional techniques and facilitates prosthodontic rehabilitation. Maxillary cancer recurrence after an initial fibula flap reconstruction presents a unique challenge. The authors report the first two cases of sequential fibula flaps after second or recurrent cancer of the maxilla. Virtual surgical planning facilitated resection with adequate tumor margins, optimized anatomic positioning of the fibula construct with three-dimensional printed plates, and enabled immediate functional dental implant placement.

Combination intraoral radiation mouthguard-positioning stent.

The sequelae of head-and-neck radiation may include hyposalivation, dysgeusia, trismus, mucositis, and osteoradionecrosis. A mouthguard used during radiation therapy can mitigate the effects of backscatter radiation from dental restorations. In addition, an intraoral positioning stent can assist in repositioning oral structures, such as the tongue, away from the field of radiation during treatment, thereby limiting dose delivery. The purpose of this article is to provide a technique to fabricate a combination prosthesis, which functions to reposition oral structures as well as mitigate the effects of backscatter from dental restorations during head-and-neck radiation therapy.

An Anatomic Analysis of Fibula Flap Mandible Reconstructions: Implications for Endosseous Implant Placement.

BACKGROUND: Precise planning and evaluation of the fibula bone are necessary if immediate endosseous implant placement is considered. Limited information is available on the anatomical dimensions or density of fibula used in mandibular reconstructions. This study aimed to describe the morphology and dimensions of the fibula used to reconstruct segmental mandibular defects and contrast the findings with the native mandible. METHODS: A retrospective analysis was performed of patients who underwent segmental mandibulectomy reconstructed with osteocutaneous fibula flaps and had at least one postoperative computed tomography scan. Fibula cross sectional dimensions and densities were evaluated with three-dimensional software. Radiographic measurements were obtained from the contralateral mandible medial to the first molar for comparison. RESULTS: Four hundred seventy-seven fibula cross sections from 159 segments were evaluated. Cross-sectional oval, quadrilateral, triangular, and pentagonal shapes differed significantly in proportion (p < 0.001). Thirty-eight percent of segments (95 percent CI, 30 to 46 percent) had differences in cross-section height greater than 1 mm (p < 0.001). Between segments within the same patient, the median height difference was 1.58 mm (range, 0.14 to 6 mm). The superior cortex density was significantly higher for the fibula than the native mandible; however, the medullary space density was significantly lower (p < 0.001). CONCLUSIONS: The current study comprises the most comprehensive description of fibula morphology in mandibular reconstructions and highlights the significant variability that exists. The findings provide justification for the added time and cost of computer-aided design and computer-aided manufacturing in centers interested in performing immediate dental implant placement, as the technology provides the necessary precision and accuracy.

Immediate Dental Implant Placement in the Oncologic Setting: A Conceptual Framework.

Historically, immediate dental implants have been reserved for patients with benign disease, with full dental rehabilitation rarely being accomplished in the oncologic setting due to concerns related to implant survival, flap compromise, and delay in initiation of adjuvant therapy. Recent developments in technology have made immediate dental implants using virtual surgical planning safe and reliable. At Memorial Sloan Kettering Cancer Center, we have implemented a workflow for immediate dental implant placement in the oncologic patient population that has become a routine part of maxillary and mandibular reconstruction. This approach begins with a multidisciplinary virtual surgical planning session and custom dental splints to be used for cutting and inset guides. Dental implants are placed intraoperatively at the time of tumor resection and reconstruction with the fibula flap. A temporary prosthesis, which can be worn during radiation therapy, is placed following a vestibuloplasty, approximately 4-6 weeks after the initial reconstruction. After the completion of radiation therapy and the resolution of edema, a permanent prosthesis is placed. When critically evaluating our experience, we have found that patients undergoing immediate dental implant placement have higher rates of implant survival and no delay in adjuvant therapy. The protocol described here in detail has successfully expanded the indications for immediate dental rehabilitation in the oncologic patient population.

Virtual Surgical Planning for Oncologic Mandibular and Maxillary Reconstruction.

Virtual surgical planning (VSP) with computer-aided design and computer-aided modeling (CAD/CAM) enables the opportunity to provide personalized medicine in complex head and neck reconstruction. This innovative technology allows ablative and reconstructive surgeons to virtually create and manipulate three-dimensional anatomic models to plan both the resection and reconstruction of complicated maxillofacial defects. Studies demonstrate improvements in preoperative planning, operative efficiency and accuracy, and postoperative outcomes. VSP facilitates immediate dental implantation in selected patients, which can improve the likelihood of achieving dental restoration. This article outlines strategies for technique optimization as well as the applications, advantages and disadvantages of VSP in complex oncologic head and neck reconstruction.

Intraoral radiation stents-Primer for clinical use in head and neck cancer therapy.

Intraoral radiation stents (IRS) are prosthetic devices that assist in the effective delivery of radiation to tumor tissues and aim to avoid unnecessary radiation to adjacent healthy tissues, thus limiting postradiotherapy toxicities. They are used to protect or displace vital structures, assist in positioning of the treatment beam for effective administration of radiotherapy, carry a radioactive material, shield healthy tissues of the oral cavity, and/or maintain the desired mouth opening during radiotherapy. With close collaboration between radiation oncologist and oral health care provider, several IRS can be fabricated by the latter for appropriate targeting and delivery of planned radiation dose and optimized treatment results. Modification of these IRS based on individual patient need is recommended to maximize prosthesis utility. The purpose of this review is to discuss the various types of IRS and highlight their clinical utility and benefits in patients receiving radiation therapy in the head and neck cancers.

Interim Implant-Supported Resection Prosthesis Following Fibula Free Flap Reconstruction of the Arch with Immediate Implants: A Novel Approach for the Oncologic Patient.

Oral cancer treatment involving the maxilla and/or mandible often results in esthetic and functional deficits that can diminish the patient's quality of life. As a result, expeditious reconstruction of the defect and dental rehabilitation is desirable. Dental rehabilitation shortly after reconstruction with an osteocutaneous free flap and resection prosthesis is a persistent challenge for patients with oncologic defects where immediate dental rehabilitation is not a possibility. Additionally, conventional prosthesis fabrication techniques are impractical or impossible due to postoperative anatomical changes and limitations in clinical armamentarium. To address these limitations, a technique and a novel implant-supported prosthetic workflow for the oncologic patient were developed to provide interim dental rehabilitation for such clinical situations. This article describes the prosthesis fabrication technique, reports short-term outcomes, and evaluates patient-reported quality-of-life outcomes using the FACE-Q Head and Neck Cancer Module.

Definitive maxillary obturator prosthesis: Timelines for fabrication and follow-up.

INTRODUCTION: A definitive maxillary obturator prosthesis can be used to rehabilitate a maxillary defect with the aim of improving speech, deglutition, and elimination of oronasal regurgitation. The aims of this study were (1) to determine the time required to fabricate a definitive maxillary obturator prosthesis and (2) to compare the fabrication and follow-up times between a patient's first and second definitive maxillary obturator prosthesis. MATERIALS AND METHODS: A retrospective review was completed of patients that had maxillary definitive obturators fabricated following head and neck surgery from 2002 to 2018 (n = 173). Demographics, clinical data, date of surgery, start date of fabrication, follow-up dates, and prosthesis follow-up data were collected. RESULTS: The median time to delivery of the patient's first definitive maxillary obturator prosthesis from the date of surgery was 7.7 months for nonradiated patients and 9.6 months for radiated patients (P ≤ .05). Additionally, there was a significant difference in the median number of appointments to fabricate the 1st definitive maxillary obturator prosthesis as compared to the 2nd prosthesis (6 vs 5; P ≤ .05). CONCLUSION: Fabrication timelines differed based on history of radiotherapy and patient experience. This data is helpful to set expectations for patients and practitioners regarding the process for prosthesis fabrication and follow-up.

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.

Prosthetic rehabilitation of the geriatric oncologic rhinectomy patient utilizing a craniofacial implant-retained nasal prosthesis.

This clinical report describes the expeditious treatment of a geriatric patient with squamous cell carcinoma of the nose treated with total rhinectomy, craniofacial implant placement, and a nasal prosthesis.

Maxillary Occlusal Splint Following Segmental Mandibulectomy and Osteocutaneous Free Flap Reconstruction - A Case Report.

Postsurgical malocclusion is a possible sequela of care following segmental mandibulectomy and osteocutaneous free flap reconstruction. Patient-specific factors may make surgical correction an impossibility. In addition, conservative occlusal adjustments may be insufficient for correction of the occlusion. An alternative approach for the management of severe postoperative malocclusion is to fabricate a maxillary occlusal splint, which establishes interocclusal articulating surfaces and facilitates mastication. The purpose of this report is to demonstrate the technique and utility of a maxillary prosthesis to correct posttreatment malocclusion in the oncologic patient.

Immediate dental implants in fibula free flaps to reconstruct the mandible: A pilot study of the short-term effects on radiotherapy for patients with head and neck cancer.

OBJECTIVES: The current pilot study aims to report short-term experience as it relates to acute radiotherapy treatment outcomes comparing patients with immediate dental implants in fibula free flap reconstructions to a historical cohort of patients with fibula free flap reconstructions without dental implants. MATERIALS AND METHODS: A retrospective review of patients who underwent segmental mandibulectomy, reconstruction with fibula free flaps, and adjuvant radiotherapy with (n = 10) and without immediate dental implants (n = 10) at a tertiary cancer center from 2015 to 2018 was performed (IRB #17-271). Incidence of postoperative complications, time to initiation of radiation therapy, development of acute toxicity, and patient reported outcome data were recorded. The radiation plans were evaluated to identify the mean and maximum doses received by the mandible and oral cavity as well as the locations of radiation global hot spots. RESULTS: There was a similar number of postoperative complications in both cohorts, with three events in the case group and two events in the control group. Patients with dental implants reported less trismus than control patients. Evaluation of the radiation treatment plans revealed similar median radiation global hot spots in both groups. CONCLUSIONS: The current study suggests that the presence of dental implants does not increase the risk of complications following surgery or during radiation treatment. Implants do not alter radiation dosimetry but do appear to positively impact early patient quality of life. Although longer follow-up is needed, based on this preliminary experience, cancer patients should be offered this type of reconstruction without fear of impacting radiation timing or delivery.

Inset Guide for the Osteocutaneous Fibula Flap with Endosseous Implants in Oncologic Jaw Reconstruction.

Reconstruction of segmental maxillary or mandibular defects with osteocutaneous free flaps can be reliably accomplished; however, buccal or lingual rotation of the fibula during rigid fixation can render immediate endosseous implant position unusable for functional dental rehabilitation. To address this issue, a custom inset guide is introduced which utilizes surface topography of the immediately placed dental implant abutments and the patient's dentition to orient the fibula segments during inset. Use of this technique facilitates successful endosseous implant position to optimize postoperative functional rehabilitation.

Primary Leiomyosarcoma of the Mandible: Posttreatment Malocclusion Treated with an Overpartial Mandibular Resection Prosthesis.

Leiomyosarcoma is a rare malignant condition occurring in the maxillofacial region in which the mandible may be affected. Management of this tumor in the mandible may include segmental mandibulectomy, osteocutaneous fibula free-flap reconstruction, endosseous implants, and postoperative radiotherapy. Posttreatment malocclusion can be managed with an overpartial mandibular resection prosthesis. The purpose of this report is to describe the expeditious oral rehabilitation of an oncologic patient with posttreatment malocclusion, demonstrating the utility of an overpartial mandibular resection prosthesis.

Oral rehabilitation following fasciocutaneous free-flap reconstruction: A retrospective study.

AIM: The aim of this study is to retrospectively, observe a consecutive series of patients with segmental mandibulectomy defects reconstructed with fasciocutaneous free flaps and mandibular resection prostheses, and to review treatment concepts for the management of such patients. SETTINGS AND DESIGN: Observational study done at Memorial Sloan Kettering Cancer Center, New York, NY, USA. MATERIALS AND METHODS: Records were reviewed of all patients who had fasciocutaneous free-flap reconstruction and fabrication of mandibular resection prostheses following segmental mandibulectomy between 2000 and 2017 at a tertiary cancer center. Mandibular resection prosthesis fabrication interval data, as well as follow-up interval data, were recorded. STATISTICAL ANALYSIS USED: Descriptive statistics. RESULTS: Twenty-one consecutive patients had mandibular resection prostheses fabricated following segmental mandibulectomy and fasciocutaneous free-flap reconstruction during the study. The median time for mandibular resection prosthesis delivery following surgery was 9 months (range 4-41 months). There was a median of two-follow-up visits (range 0-4) within the first 90 days of mandibular resection prosthesis delivery. CONCLUSIONS: Oral rehabilitation with mandibular resection prosthesis following segmental mandibulectomy and fasciocutaneous free-flap reconstruction is an attainable treatment goal for the oncologic patient. Reviewing the proposed course of care is helpful for patient management.

Sarcomas of the mandible.

INTRODUCTION: Sarcomas of the mandible are extremely rare tumors, with osteosarcoma being the most common, followed by Ewing's sarcoma MATERIALS AND METHODS: A retrospective review of the clinical records, imaging studies, and pathology slides of patients with sarcoma of the mandible at a Tertiary Care Cancer Center from 1998 to 2014 was undertaken. The impact of neoadjuvant chemotherapy and postoperative radiotherapy with or without chemotherapy was studied, and factors impacting upon local control and disease-specific survival were analyzed. RESULTS: Twenty-two patients were treated over the study period, comprising of 15 males and seven females. External swelling, intraoral growth, or facial numbness were the presenting symptoms. Eighteen patients had osteosarcoma and four had the Ewing's sarcoma. Nine patients received neoadjuvant chemotherapy. All but one patient underwent surgery. Eleven had negative margins, with 90% recurrence-free survival at 3 years, compared to 10 with positive or close margins, leading to 67% recurrence-free survival. None of the patients receiving neoadjuvant chemotherapy developed recurrence and all were alive at 3 years. The impact of postoperative radiotherapy or adjuvant chemotherapy was not statistically significant. CONCLUSIONS: Wide surgical resection with negative margins remains the hallmark of surgical treatment.

Intraoral Rehabilitation After Marginal Mandibulectomy.

PURPOSE: To report the feasibility of oral rehabilitation in patients who had undergone marginal mandibulectomy and to describe the factors that impact the selection of a mandibular resection prosthesis. MATERIALS AND METHODS: A retrospective review of patients who had undergone marginal mandibulectomy over a 14-year period at a tertiary care cancer center was undertaken. Measurements of the vertical height and width of the mandible and the distance between the alveolar crest and mandibular canal were measured after marginal mandibulectomy. The feasibility and success of tooth-borne or implant-supported resection prostheses were measured. RESULTS: Following marginal mandibulectomy, the median heights between the alveolar crest and lower border of the mandible were 21.8 mm, 17.7 mm, and 14.3 mm in the anterior, premolar, and molar regions, respectively. However, the median distances between the alveolar crest and the mandibular canal in the premolar and molar regions were only 3.98 and 3.4 mm, respectively. These residual bone measurements are not satisfactory for implant-supported mandibular resection prostheses, which can be considered only in the anterior region of the mandible. Patients with marginal mandibulectomy in the premolar and molar regions can only be rehabilitated with removable dentures, provided they have remaining stable teeth to clasp and anchor the removable denture. CONCLUSION: Implant-supported resection prostheses after marginal mandibulectomy are feasible only in the anterior segment of the mandible and are not possible in the premolar and molar regions.

Immediate Dental Implantation in Oncologic Jaw Reconstruction: Workflow Optimization to Decrease Time to Full Dental Rehabilitation.

Full dental rehabilitation following segmental mandibulectomy or maxillectomy for oncologic tumor ablation should be the goal for every patient. But despite advances in technology and reconstructive techniques, many patients do not achieve timely or complete oral rehabilitation. Recognizing this fault, we recently adopted an innovative workflow to increase the number of patients undergoing dental restoration, irrespective of tumor pathology or need for adjuvant radiotherapy. Preoperatively, every osseous jaw reconstruction undergoes virtual surgical planning to incorporate the placement of endosseous implants into the fibula osteocutaneous free flap. The dental implants are then placed intraoperatively at the time of tumor ablation and reconstruction. Four-to-six weeks following the initial surgery, the patient returns to the operating room for vestibuloplasty and exposure of the dental implants. Within 3 days of the vestibuloplasty, a temporary dental prosthesis is placed in the dental clinic, and the patient can then begin radiation therapy if needed. Following adjuvant radiation therapy, the temporary prosthesis can be replaced with a permanent one. At our institution, this innovative workflow has allowed for earlier aesthetic restoration of the jaw and greatly expanded the number of patients able to achieve oral rehabilitation. Herein, we describe this innovative workflow and provide technical pearls for successful execution.

Novel intraoperative radiotherapy utilizing prefabricated custom three-dimensionally printed high-dose-rate applicators.

BACKGROUND: Intraoperative radiotherapy (IORT) is an effective strategy for the delivery of high doses of radiotherapy to a residual tumor or resection cavity with relative sparing of nearby healthy tissues. This strategy is an important component of the multimodality management of pediatric soft tissue sarcomas, particularly in cases where patients have received prior courses of external beam radiotherapy. PURPOSE: Tumor beds with significant topographic irregularity remain a therapeutic challenge because existing IORT technologies are typically most reliable with flat surfaces. To address this limitation, we have developed a novel strategy to create custom, prefabricated high-dose-rate (HDR)-IORT applicators designed to match the shape of an anticipated surgical cavity. METHODS AND MATERIALS: Silastic applicators are constructed using three-dimensional (3D) printing and are derived from volumetric segmentation of preoperative imaging. RESULTS: HDR preplanning with the applicators improves dosimetric accuracy and minimizes incremental operative time. In this report, we describe the fabrication process for the 3D-printed applicators and detail our experience utilizing this strategy in two pediatric patients who underwent HDR-IORT as part of complex base of skull sarcoma resections. CONCLUSIONS: Early experience suggests that usage of the custom applicators is feasible, versatile for a variety of clinical situations, and enables the uniform delivery of high superficial doses of radiotherapy to irregularly shaped surgical cavities.