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.

Oncology Curricula in Postgraduate General Dentistry Programs: a Survey of Residency Program Directors.

Management of patients undergoing treatment for cancer requires a multidisciplinary team including general dentistry providers; however, the relative knowledge and training of general dentists in the management of this patient population are relatively unknown. The purpose of this study was to assess the oncology curricula of postgraduate general dentistry training programs, from the perspective of the program directors, to better understand the opportunities for and/or barriers to dental care for cancer patients. A cross-sectional survey was sent to the 275 Commission on Dental Accreditation-accredited programs; 82 program directors responded (response rate, 30%). More than 50% of respondents indicated "none" or "little" curricular emphasis on cancer biology, bone marrow transplantation, immunotherapy, or prosthetics for use during head and/or neck surgery. Conversely, more than 50% of respondents indicated "moderate" or "substantial" emphasis on acute oral effects of cancer-related therapy, long-term oral effects of cancer-related therapy, antiresorptive medication pharmacology, radiotherapy techniques and biological effects, and osteonecrosis of the jaw. Residents had the most experience with radiotherapy patients and the least with bone marrow or transplantation patients. Overall, general dentistry program directors were enthusiastic to participate in the multidisciplinary team but reported challenges to including oncology curricula in residency training programs. Training for general dentistry providers in formalized postgraduate residency programs may be variable or limited-as a result, communication regarding patient management is critical. Opportunities exist to enhance the general dentistry curricula and, thereby, improve access to dental care for patients receiving treatment for cancer.

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.

Radiation dose enhancement associated with contemporary dental materials.

STATEMENT OF PROBLEM: Electron backscatter radiation from dental materials can contribute to soft tissue injury in patients undergoing head and neck radiation therapy. PURPOSE: The dose enhancement from the materials used for prosthodontic restoration of the dentition has not been well quantified. This study reports the magnitude of backscatter dose from the contemporary dental materials lithium disilicate and zirconia as compared with high-noble alloy and investigates the role of a spacer material in mitigating this effect. MATERIAL AND METHODS: Three flat slabs of dental materials high-noble alloy, lithium disilicate, and zirconia with thicknesses of 1.5 and 3 mm were irradiated with 6-MV photons from a clinical linear accelerator. Measurements were made using a thin-window parallel-plate ionization chamber placed at 0, 1, 3, and 5 mm from the material. One millimeter of poly(methyl methacrylate) or thermoplastic material was used to cover the dental material and measure the effect on the adjacent dose enhancement. RESULTS: Dose enhancements between 8% and 50% were recorded adjacent to the dental restoration materials. The largest enhancements occurred for the material of the highest density, the high-noble alloy. Dose enhancement was substantially lower for lithium disilicate (8%) and zirconia (30%). The thickness of the restoration material did not significantly affect dose enhancement. The dose enhancement decreased with distance from the material, dropping to <10% for all materials at 3 mm. CONCLUSIONS: Contemporary dental restorations enhance the backscatter dose. The presence of dental restorations may warrant the use of a stent to create separation from these materials as this can mitigate the effect.

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.

Oral rehabilitation of the cancer patient: A formidable challenge.

Rehabilitation of oral functions following surgery on the jaws is a goal that is often difficult to achieve. Removable dentures supported by remaining teeth or gum are often unstable and seldom satisfactory. On the other hand, endosseous (dental) implants offer a mechanism to provide stability to the dentures. This review, discusses factors related to the tumor, patient, treatment, and physicians which impact upon the feasibility and success of dental implants in patients with oral cancer.

Intraoral angiosarcoma: treatment with a brachytherapy prosthesis.

Angiosarcomas are rare, malignant neoplasms of vascular origin that account for less than 1% of all soft tissue tumors. Angiosarcomas of the oral cavity are especially rare, and brachytherapy may be prescribed as a localized treatment to manage these malignancies. Intraoral brachytherapy requires collaboration between the radiation oncologist and a dental professional for the fabrication of the brachytherapy delivery prosthesis. This clinical report describes an intraoral angiosarcoma and the fabrication of an intraoral brachytherapy prosthesis to manage this malignancy.

Fabrication of a provisional nasal prosthesis.

A technique for making a provisional nasal prosthesis for interim use after the ablation of a midface tumor is described. The technique is especially useful for the re-creation of a nasal form in an expedient and cost-effective manner. A preoperative definitive cast, or moulage, of the patient that includes a nasal form is used to fabricate a vacuum form of the midface. The vacuum form is evaluated on the patient, the extension is adjusted, and an external adhesive knit liner is applied to give the appearance of a contoured nasal bandage. The provisional nasal prosthesis is attached with medical adhesive tape and removed daily by the patient. The prosthesis is easily replaced during the course of treatment and has been found to be functional and esthetically acceptable to those patients receiving care from the Dental Service at Memorial Sloan Kettering Cancer Center.

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.

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.

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.

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.

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.