Prognostic factors associated with a restricted mouth opening (trismus) in patients with head and neck cancer:Systematic review

BACKGROUND: To prescribe early trismus therapy, prognostic factors influencing the restricted mouth opening should be identified first. Our aim is to present an overview of these factors in patients with head and neck cancer. METHODS: PubMed, Cochrane, EMBASE, and CINAHL were searched using terms related to head and neck cancer and mouth opening. Risk of bias was assessed using the "Quality in Prognosis Studies" tool. A best evidence synthesis was performed. RESULTS: Of the identified 1418 studies, 53 were included. Three studies contained a prognostic multivariate model for a restricted mouth opening. CONCLUSIONS: Patients with head and neck cancer will most likely develop a restricted mouth opening when they have a large tumor near the masticatory muscles that requires extensive cancer treatment. A restricted mouth opening most likely occurs within 6 months after cancer treatment. Further research is necessary on factors related to healing tendency or pain intensity

Full 3-D digital planning of implant-supported bridges in secondary mandibular reconstruction with prefabricated fibula free flaps

Objectives In the reconstruction of maxillary or mandibular continuity defects in dentate patients, the most favourable treatment is placement of implant-retained crowns or bridges in a bone graft that reconstructs the defect. Proper implant positioning is often impaired by suboptimal placement of the bone graft. This case describes a new technique of a full digitally planned, immediate restoration, two-step surgical approach for reconstruction of a mandibular defect using a free vascularised fibula graft with implants and a bridge. Procedure A 68-year-old male developed osteoradionecrosis of the mandible. The resection, cutting and implant placement in the fibula were virtually planned. Cutting and drilling guides were 3-D printed, and the bridge was computer aided design-computer aided manufacturing (CAD-CAM) milled. During the first surgery, two implants were placed in the fibula according to the digital planning, and the position of the implants was scanned using an intra-oral optical scanner. During the second surgery, a bridge was placed on the implants, and the fibula was harvested and fixed in the mandibular defect, guided by the occlusion of the bridge. Conclusion Three-dimensional planning allowed for positioning of a fibula bone graft by means of an implant-supported bridge, which resulted in a functional position of the graft and bridge.</p

Full 3-D digital planning of implant-supported bridges in secondary mandibular reconstruction with prefabricated fibula free flaps

Objectives In the reconstruction of maxillary or mandibular continuity defects in dentate patients, the most favourable treatment is placement of implant-retained crowns or bridges in a bone graft that reconstructs the defect. Proper implant positioning is often impaired by suboptimal placement of the bone graft. This case describes a new technique of a full digitally planned, immediate restoration, two-step surgical approach for reconstruction of a mandibular defect using a free vascularised fibula graft with implants and a bridge. Procedure A 68-year-old male developed osteoradionecrosis of the mandible. The resection, cutting and implant placement in the fibula were virtually planned. Cutting and drilling guides were 3-D printed, and the bridge was computer aided design-computer aided manufacturing (CAD-CAM) milled. During the first surgery, two implants were placed in the fibula according to the digital planning, and the position of the implants was scanned using an intra-oral optical scanner. During the second surgery, a bridge was placed on the implants, and the fibula was harvested and fixed in the mandibular defect, guided by the occlusion of the bridge. Conclusion Three-dimensional planning allowed for positioning of a fibula bone graft by means of an implant-supported bridge, which resulted in a functional position of the graft and bridge.</p

Full 3-D digital planning of implant-supported bridges in secondary mandibular reconstruction with prefabricated fibula free flaps

Objectives In the reconstruction of maxillary or mandibular continuity defects in dentate patients, the most favourable treatment is placement of implant-retained crowns or bridges in a bone graft that reconstructs the defect. Proper implant positioning is often impaired by suboptimal placement of the bone graft. This case describes a new technique of a full digitally planned, immediate restoration, two-step surgical approach for reconstruction of a mandibular defect using a free vascularised fibula graft with implants and a bridge. Procedure A 68-year-old male developed osteoradionecrosis of the mandible. The resection, cutting and implant placement in the fibula were virtually planned. Cutting and drilling guides were 3-D printed, and the bridge was computer aided design-computer aided manufacturing (CAD-CAM) milled. During the first surgery, two implants were placed in the fibula according to the digital planning, and the position of the implants was scanned using an intra-oral optical scanner. During the second surgery, a bridge was placed on the implants, and the fibula was harvested and fixed in the mandibular defect, guided by the occlusion of the bridge. Conclusion Three-dimensional planning allowed for positioning of a fibula bone graft by means of an implant-supported bridge, which resulted in a functional position of the graft and bridge.</p

Full 3-D digital planning of implant-supported bridges in secondary mandibular reconstruction with prefabricated fibula free flaps

Objectives In the reconstruction of maxillary or mandibular continuity defects in dentate patients, the most favourable treatment is placement of implant-retained crowns or bridges in a bone graft that reconstructs the defect. Proper implant positioning is often impaired by suboptimal placement of the bone graft. This case describes a new technique of a full digitally planned, immediate restoration, two-step surgical approach for reconstruction of a mandibular defect using a free vascularised fibula graft with implants and a bridge. Procedure A 68-year-old male developed osteoradionecrosis of the mandible. The resection, cutting and implant placement in the fibula were virtually planned. Cutting and drilling guides were 3-D printed, and the bridge was computer aided design-computer aided manufacturing (CAD-CAM) milled. During the first surgery, two implants were placed in the fibula according to the digital planning, and the position of the implants was scanned using an intra-oral optical scanner. During the second surgery, a bridge was placed on the implants, and the fibula was harvested and fixed in the mandibular defect, guided by the occlusion of the bridge. Conclusion Three-dimensional planning allowed for positioning of a fibula bone graft by means of an implant-supported bridge, which resulted in a functional position of the graft and bridge.</p

Full 3-D digital planning of implant-supported bridges in secondary mandibular reconstruction with prefabricated fibula free flaps

Objectives In the reconstruction of maxillary or mandibular continuity defects in dentate patients, the most favourable treatment is placement of implant-retained crowns or bridges in a bone graft that reconstructs the defect. Proper implant positioning is often impaired by suboptimal placement of the bone graft. This case describes a new technique of a full digitally planned, immediate restoration, two-step surgical approach for reconstruction of a mandibular defect using a free vascularised fibula graft with implants and a bridge. Procedure A 68-year-old male developed osteoradionecrosis of the mandible. The resection, cutting and implant placement in the fibula were virtually planned. Cutting and drilling guides were 3-D printed, and the bridge was computer aided design-computer aided manufacturing (CAD-CAM) milled. During the first surgery, two implants were placed in the fibula according to the digital planning, and the position of the implants was scanned using an intra-oral optical scanner. During the second surgery, a bridge was placed on the implants, and the fibula was harvested and fixed in the mandibular defect, guided by the occlusion of the bridge. Conclusion Three-dimensional planning allowed for positioning of a fibula bone graft by means of an implant-supported bridge, which resulted in a functional position of the graft and bridge.</p

Full 3-D digital planning of implant-supported bridges in secondary mandibular reconstruction with prefabricated fibula free flaps

Objectives In the reconstruction of maxillary or mandibular continuity defects in dentate patients, the most favourable treatment is placement of implant-retained crowns or bridges in a bone graft that reconstructs the defect. Proper implant positioning is often impaired by suboptimal placement of the bone graft. This case describes a new technique of a full digitally planned, immediate restoration, two-step surgical approach for reconstruction of a mandibular defect using a free vascularised fibula graft with implants and a bridge. Procedure A 68-year-old male developed osteoradionecrosis of the mandible. The resection, cutting and implant placement in the fibula were virtually planned. Cutting and drilling guides were 3-D printed, and the bridge was computer aided design-computer aided manufacturing (CAD-CAM) milled. During the first surgery, two implants were placed in the fibula according to the digital planning, and the position of the implants was scanned using an intra-oral optical scanner. During the second surgery, a bridge was placed on the implants, and the fibula was harvested and fixed in the mandibular defect, guided by the occlusion of the bridge. Conclusion Three-dimensional planning allowed for positioning of a fibula bone graft by means of an implant-supported bridge, which resulted in a functional position of the graft and bridge.</p

The use of stretching devices for treatment of trismus in head and neck cancer patients:a randomized controlled trial

PURPOSE: To compare the effects of two stretching devices, the TheraBite® Jaw Motion Rehabilitation System™ and the Dynasplint Trismus System®, on maximal mouth opening in head and neck cancer patients. METHODS: Patients were randomly assigned to one of two exercise groups: the TheraBite® Jaw Motion Rehabilitation System™ group or the Dynasplint Trismus System® group. Patients performed stretching exercises for 3 months. During the three study visits, maximal mouth opening was measured and the patients completed questionnaires on mandibular function and quality of life. RESULTS: In our study population (n = 27), five patients did not start the exercise protocol, eight patients discontinued exercises, and two patients were lost to follow-up. No significant differences regarding the change in mouth opening between the two devices were found. Patients had an increase in MMO of 3.0 mm (IQR - 2.0; 4.0) using the TheraBite® Jaw Motion Rehabilitation System™ and 1.5 mm (IQR 1.0; 3.0) using the Dynasplint Trismus System®. Exercising with either stretching device was challenging for the patients due to the intensive exercise protocol, pain during the exercises, fitting problems with the stretching device, and overall deterioration of their medical condition. CONCLUSIONS: The effects of the two stretching devices did not differ significantly in our study population. The factors described, influencing the progression of stretching exercises, need to be taken into account when prescribing a similar stretching regimen for trismus in head and neck cancer patients. TRIAL REGISTRATION: NTR - Dutch Trial Register number: 5589

Criterion for trismus in head and neck cancer patients:a verification study

Several cut-off points for trismus in head and neck cancer patients have been used. A mouth opening of 35 mm or less is most frequently used as cut-off point. Due to the variation in cut-off points, prevalence, risk factors and treatment outcomes of trismus cannot be studied in a uniform manner. To provide uniformity, we aimed to verify the cut-off point of 35 mm or less. Additionally, we aimed to determine associated covariates with reported difficulties when opening the mouth

A continuous-discontinuous model for crack branching

This is the peer reviewed version of the following article: Tamayo, E. [et al.]. A continuous-discontinuous model for crack branching. "International journal for numerical methods in engineering", 5 Octubre 2019, vol. 120, núm. 1, p. 86-104, which has been published in final form at https://doi.org/10.1002/nme.6125. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.A new continuous-discontinuous model for fracture that accounts for crack branching in a natural manner is presented. It combines a gradient-enhanced damage model based on nonlocal displacements to describe diffuse cracks and the extended finite element method (X-FEM) for sharp cracks. Its most distinct feature is a global crack tracking strategy based on the geometrical notion of medial axis: the sharp crack propagates following the direction dictated by the medial axis of a damage isoline. This means that, if the damage field branches, the medial axis automatically detects this bifurcation, and a branching sharp crack is thus easily obtained. In contrast to other existing models, no special crack-tip criteria are required to trigger branching. Complex crack patterns may also be described with this approach, since the X-FEM enrichment of the displacement field can be recursively applied by adding one extra term at each branching event. The proposed approach is also equipped with a crack-fluid pressure, a relevant feature in applications such as hydraulic fracturing or leakage-related events. The capabilities of the model to handle propagation and branching of cracks are illustrated by means of different two-dimensional numerical examples.Peer ReviewedPostprint (author's final draft