RESUMO
This clinical report details the rehabilitation of a patient who underwent a total rhinectomy, subsequent adjuvant radiation therapy, and eventual prosthetic rehabilitation but then developed an empirically diagnosed medical adhesive intolerance. With the aid of digital planning and real time navigation, 2 zygomatic implants were placed by using a flapless surgical approach followed by early delivery of an interim prosthesis. In spite of the failure of 1 craniofacial implant, definitive restoration was accomplished by using a titanium bar, double magnetic attachments, and a new silicone prosthesis.
Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante , Implantação Dentária Endóssea , Seguimentos , Humanos , Nariz/cirurgia , Implantação de PróteseRESUMO
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.
Assuntos
Materiais Dentários , Porcelana Dentária , Ligas Dentárias , Planejamento de Prótese Dentária , Humanos , Teste de Materiais , Doses de Radiação , ZircônioRESUMO
OBJECTIVE: The objective of this study was to assess characteristics of patients with mandibular osteoradionecrosis (ORN) of severity necessitating segmental mandibulectomy and osteocutaneous free flap reconstruction. STUDY DESIGN: This study is a retrospective review of patients who underwent free flap reconstruction of the mandible at the UCLA Medical Center between January 2016 and February 2020 secondary to ORN. RESULTS: Twenty-nine charts with detailed dental and medical records were identified. Hypertension was reported in 14 of 29 patients, diabetes in 2 of 29, osteoporosis in 2 of 29, antiresorptive use in 3 of 29, tobacco use in 15 of 29, and alcohol use in 19 of 29. Twenty-three patients initially had stage III-IV cancer. The median radiation dose was 68 Gy and median time to ORN was 5.2 years. Chemotherapy was given in 21 patients and 4 had previous mandibular surgery. Twelve of 29 patients had surgical procedures identified as the causative factor and 17 of 29 occurred spontaneously. Median decayed, missing, and filled teeth score was 17 and 17 of 29 patients had grade II-IV periodontitis. Periodontitis was present in 8 of 17 of spontaneous and 1 of 12 of surgery cases. Twenty-five of 29 cases occurred in the same oral sextant as the tumor. CONCLUSION: Severe ORN occurred at doses >60 Gy in most cases. Location of the primary tumor was predictive of site of ORN and only molars were involved when precipitated by tooth extraction. Risk of ORN persists indefinitely.
Assuntos
Doenças Mandibulares , Osteorradionecrose , Procedimentos de Cirurgia Plástica , Humanos , Mandíbula/cirurgia , Doenças Mandibulares/etiologia , Doenças Mandibulares/patologia , Doenças Mandibulares/cirurgia , Osteotomia Mandibular/efeitos adversos , Osteorradionecrose/etiologia , Osteorradionecrose/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Estudos RetrospectivosRESUMO
Fibula flap reconstruction with primary dental implant placement has been established as a successful procedure for composite mandibular defects. When using virtual surgical planning, these techniques typically require additional personnel and materials preoperatively and intraoperatively to fabricate occlusal-based guidance and prosthesis. The authors present a technique utilizing a custom-made implant-supported prosthesis completed before surgery that greatly reduces lead time and needed resources. The authors follow the established workflow of segmental mandibulectomy and fibula flap reconstruction using premanufactured cutting guides and placement of dental implants. Cylindrical holes along the implant axes are included in the printed surgical model provided by the guide manufacturer. Acrylic resin and abutments are added to the model to a positioning stent for use during surgery that does not require intraoperative modification before fibula inset. This ensures optimal position for facial esthetics and fixed dental rehabilitation. The presented technique uses printed models already provided by the guide manufacturer, reducing preparation time and requiring fewer personnel and materials intraoperatively. This is an approach to the jaw-in-a-day procedure with a lower barrier to entry that may be used by new craniofacial teams.