Jon Wagner - Academia.edu (original) (raw)

Papers by Jon Wagner

Research paper thumbnail of Biomechanical Optimization of Bone Plates Used in Rigid Fixation of Mandibular Symphysis Fractures

Journal of Oral and Maxillofacial Surgery, 2010

To design and optimize a bone plate for fractures of the mandibular symphysis that will provide m... more To design and optimize a bone plate for fractures of the mandibular symphysis that will provide maximum fracture stability with minimal implanted volume and patient intrusion. The design will be driven by the unique biomechanics specific to this fracture location. A finite element model of a fractured human mandible was created using computed tomography scans. The boundary conditions included simulating molar, canine, and incisal loading. The bone plate design process included a shape optimization routine and design parameter analysis using the model. The optimized bone plate design was finally compared with standard bone plate configurations according to stress and strain measures. Compared with the miniplate combination, the InterFlex III plate, with the same thickness and just 14% more implanted volume, had only 55% of the plate stress and 25% less fracture strain under the strongest loads considered by the model. Compared with the band/fracture plate combination, the InterFlex plate had 88% of the fracture strain and 74% of the plate stress, despite having only 60% of the plate volume. The results have demonstrated that the new optimized plate is a hybrid of fixation hardware with the small profile of the smallest miniplate configuration and the superior fixation strength and safety that exceeds that of the larger fracture plate configuration.

Research paper thumbnail of Mandibular defect reconstruction utilizing preoperative 3D modeling, plate pre-bending and a novel triad graft: a case report

Stomatological Disease and Science, 2017

The reconstruction of boney defects of the mandible are a challenge in surgical therapy despite a... more The reconstruction of boney defects of the mandible are a challenge in surgical therapy despite advances in bone grafting. This case study details a 30-year-old female who sustained a gunshot wound to the mandible leaving a 5 cm boney defect. This defect was reconstructed utilizing preoperative three-dimensional (3D) planning, an accurately pre-bent reconstruction plate, and a novel "triad" construct of autogenous bone graft, demineralized bone matrix, and an osteoprotective membrane. This reconstruction workflow allowed maintenance of the contour of the mandible and bone regeneration while also acting as a barrier to other tissues. This new technique reduced operative donor site morbidity and decreased surgical time dramatically, allowing the patient to be discharged the same day. The patient has a 5-year follow-up with panorex film and a biopsy of the graft area showing normal cortical bone. This case report illustrates the combination of advanced technology and novel products which can decrease operating time, decrease anesthesia time, increase precision, and most importantly decrease patient morbidity.

Research paper thumbnail of Experimental and Numerical Modeling of Screws Used for Rigid Internal Fixation of Mandibular Fractures

Modelling and Simulation in Engineering, 2008

Experimental and numerical methods are used to explore the stresses generated around bone screws ... more Experimental and numerical methods are used to explore the stresses generated around bone screws used in rigid internal fixation of mandibular fractures. These results are intended to aid in decisions concerning both the design and the use of these bone screws. A finite element (FE) model of a human mandible is created with a fixated fracture in the parasymphyseal region. The mandibular model is anatomically loaded, and the forces exerted by the fixation plate onto the simplified screws are obtained and transferred to another finite element submodel of a screw implant embedded in a trilaminate block with material properties of cortical and cancellous bone. The stress in the bone surrounding the screw implant is obtained and compared for different screw configurations. The submodel analyses are further compared to and validated with simple axial experimental and numerical screw pull-out models. Results of the screw FE analysis (FEA) submodel show that a unicortical screw of 2.6 mm ma...

Research paper thumbnail of Effects of Topical Copper Tripeptide Complex on CO2 Laser–Resurfaced Skin

Archives of Facial Plastic Surgery, 2006

To evaluate the role of skin care products that contain a copper tripeptide complex, glycyl-L-his... more To evaluate the role of skin care products that contain a copper tripeptide complex, glycyl-L-histidyl-L-lysine-Cu 2ϩ (GHK-Cu), in treating carbon dioxide (CO 2) laser-resurfaced skin. Methods: Patients meeting the inclusion criteria underwent circumoral skin resurfacing using a CO 2 laser at standard settings. Patients were then randomized to receive posttreatment skin regimens with or without GHK-Cu. Evaluations for erythema throughout the posttreatment period were performed using computer software and blinded evaluators. In addition, overall improvement in wrinkles and overall improvement in skin appearance 12 weeks after treatment were assessed. Patients completed a validated questionnaire before and 12 weeks after treatment. Results: Thirteen patients completed the study. Computer analysis and blinded evaluators found no statistically significant differences between groups for earlier resolution of erythema. All the patients experienced significant improvement in wrinkles and overall skin quality, but no differences were found between groups. The results of the questionnaire indicated a significant difference in the posttreatment improvement of overall skin quality for patients using GHK-Cu (P =.04). Conclusions: Copper tripeptide complex (GHK-Cu) skin care products placed on CO 2 laser-resurfaced skin offered no significant reduction or resolution of posttreatment erythema. Objective evaluation found no significant improvement in wrinkles or overall skin quality. However, patient satisfaction was significantly higher for those who used GHK-Cu skin care products after CO 2 laser skin resurfacing.

Research paper thumbnail of Reviews from Current Literature

Journal of Oral Implantology, 1998

Research paper thumbnail of Osteosynthesis plate, method of customizing same, and method for installing same

Research paper thumbnail of The Effects of Frictionless/Frictional Contact Boundary Conditions in Finite Element Modeling of Mandibular Fractures

Multidiscipline Modeling in Materials and Structures, 2008

Finite element (FE) modeling of the human dentate mandible is the method of choice currently used... more Finite element (FE) modeling of the human dentate mandible is the method of choice currently used for simulating structural fracture analyses in the mandibular region. A finite element model of a parasymphyseal fracture with an internal rigid fixation plate-screw system has been developed to compare the effects of including frictionless/frictional contact boundary conditions at the fracture site. It is common

Research paper thumbnail of Dog Bites of the Scalp, Face, and Neck in Children

The Laryngoscope, 2003

To update the surgical management of injuries from dog bites of the scalp, face, and neck in chil... more To update the surgical management of injuries from dog bites of the scalp, face, and neck in children. Retrospective case review. A retrospective review of 44 children with dog bites of the scalp, face, and neck was carried out at the University of New Mexico Health Sciences Center (Albuquerque, NM) between January 1, 1995, and December 31, 2000. Data on demographics, hospitalization, surgery, and outcome were collected and entered into an Access 2000 database. The children ranged in age from 1.0 to 12.1 years. The mean age of the study population was 5.2 years (+/-2.9 y standard deviation). Sixteen severely injured children (36%) were hospitalized to repair damage to the airway and blood vessels of the neck or to treat hemodynamic compromise. The length of stay in hospital ranged from 1 to 16 days. The most common injury in these children was a scalp laceration (57%). Twenty-six less severely injured children (64%) were not hospitalized. The most common surgery in these children (88%) was repair of multiple facial lacerations. Attention deficit hyperactivity disorder was noted in the medical records of 12 children (29%). Complications occurred in five children (31%) who were hospitalized and nine children (35%) who were not hospitalized. The injured child is typically a 5-year-old boy attacked by a familiar dog at home or in the local neighborhood. Children with the diagnosis of attention deficit hyperactivity disorder appear to be at a higher risk of dog bite injuries and should be monitored during interactions with dogs. The goal of surgical management for severely injured children is to avoid immediate mortality and to establish a schedule of multiple-staged procedures for revision surgeries. An optimal cosmetic result is the principal goal for less severely injured children.

Research paper thumbnail of Modeling of Screw-Plate Systems for Mandibular Fracture Repair

Advances in Bioengineering, 2004

Fractures of the mandible are a common form of traumatic injury. These fractures may be repaired ... more Fractures of the mandible are a common form of traumatic injury. These fractures may be repaired using miniplates secured to cortical bone with screws. In the present research, the authors measure the pull-out strengths of cortical screws using a standard test paradigm and develop a ...

Research paper thumbnail of The Effects of Varying Frictional Contact Boundary Conditions in Finite Element Analysis of Mandibular Parasymphyseal Fracture

ASME 2007 Summer Bioengineering Conference, 2007

This paper describes a technical assessment of operating Interprovincial Pipe Line Inc.'s reactiv... more This paper describes a technical assessment of operating Interprovincial Pipe Line Inc.'s reactivated Line 1 segments from Hardisty, Alberta to Regina, Saskatchewan and active Line 13 segments from Regina to Gretna, Manitoba at a maximum operating pressure equivalent to 80 percent of the test pressure. The assessment addressed the metallurgy and manufacturing methods of the pipe materials, the operating history, the hydrostatic test results, and the analysis of the hydrostatic test failures. From the assessment it was concluded that the existing portions of original Line 1 and all of existing Line 13 that will be used as parts of the proposed New Line 13 are capable of being operated at pressure levels of 80 percent of the 1993/1994 test pressures.

Research paper thumbnail of Finite Element Analysis of Fixation Plates for Mandibular Fracture Stabilization

Plastic and Reconstructive Surgery, 2005

Wolters Kluwer Health may email you for journal alerts and information, but is committed to maint... more Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining your privacy and will not share your personal information without your express consent. For more information, please refer to our Privacy Policy. ... Skip Navigation Links Home > ...

Research paper thumbnail of Salvage of partial facial soft tissue avulsions with medicinal leeches

Otolaryngology - Head and Neck Surgery, 2004

BACKGROUND: Medicinal leeches have been demonstrated to be extremely useful and safe in the salva... more BACKGROUND: Medicinal leeches have been demonstrated to be extremely useful and safe in the salvage of venous outflow compromised tissue, particularly in digit replants and various forms of flaps. OBJECTIVE: To demonstrate the utility of medicinal leeches in the salvage of venous outflow-compromised traumatic soft tissue avulsions in key facial structures. METHODS: A retrospective review of 4 cases involving the external ear, nose, lip, and scalp in which apparent venous outflow compromise was present. Medicinal leeches were applied acutely in each of these 4 cases, salvaging each of the partially avulsed soft tissue segments. RESULTS: Complete or near complete salvage of each soft tissue segment after using medicinal leeches. CONCLUSIONS: Although it is unusual for a partial soft tissue avulsion of the face to require medicinal leech therapy, situations may occur in which there is adequate arterial inflow but inadequate venous outflow. In such cases, medicinal leeches may play a ve...

Research paper thumbnail of Rapid 3-dimensional prototyping for surgical repair of maxillofacial fractures: a technical note

Journal of Oral and Maxillofacial Surgery, 2004

Research paper thumbnail of Assessement of Proplast-Teflon disc replacements

Journal of Oral and Maxillofacial Surgery, 1990

Research paper thumbnail of Infection Rates Following Perioperative Prophylactic Antibiotics Versus Postoperative Extended Regimen Prophylactic Antibiotics in Surgical Management of Mandibular Fractures

Journal of Oral and Maxillofacial Surgery, 2009

Purpose: To determine whether or not an extended regimen of prophylactic antibiotics following ei... more Purpose: To determine whether or not an extended regimen of prophylactic antibiotics following either open or closed reduction of mandibular fractures is beneficial in lowering the rate of infection in post-operative patients. Patients and Methods: This study is a retrospective chart review of 150 patients treated operatively for both complicated and uncomplicated mandibular fractures at

Research paper thumbnail of Finite Element Analysis of Screw-Plate Systems for Fixation of Parasymphyseal Fractures of the Mandible

Journal of Mechanics, 2007

Finite Element Modeling was used to compare the efficacy of common screw-plate configurations use... more Finite Element Modeling was used to compare the efficacy of common screw-plate configurations used for fixation of parasymphyseal fractures of the mandible. Measures of Von Mises stress on the screw bone interface, as well as principal strain in the reduced fracture region, were used in this comparison. This study also explored differences between orthotropic and isotropic modeling practices and compared the effect of mastication forces on both the fractured and intact halves of the mandible. The results of this analysis showed no major differences between configurations from a mechanistic point of view. This suggests that the use of any of the studied screw-plate configurations will not increase chances for post-operative complications. Furthermore, little difference is seen between analyses with either orthotropic or isotropic material properties. The inclusion of orthotropic properties can thus be avoided in future studies with similar boundary and plating conditions. Mastication...

Research paper thumbnail of Mechanical Design Optimization of Bioabsorbable Fixation Devices for Bone Fractures

Journal of Craniofacial Surgery, 2009

Bioabsorbable bone plates can eliminate the necessity for a permanent implant when used to fixate... more Bioabsorbable bone plates can eliminate the necessity for a permanent implant when used to fixate fractures of the human mandible. They are currently not in widespread use because of the low strength of the materials and the requisite large volume of the resulting bone plate. The aim of the current study was to discover a minimally invasive bioabsorbable bone plate design that can provide the same mechanical stability as a standard titanium bone plate. A finite element model of a mandible with a fracture in the body region is subjected to bite loads that are common to patients postsurgery. The model is used first to determine benchmark stress and strain values for a titanium plate. These values are then set as the limits within which the bioabsorbable bone plate must comply. The model is then modified to consider a bone plate made of the polymer poly-L/DL-lactide 70/30. An optimization routine is run to determine the smallest volume of bioabsorbable bone plate that can perform and a titanium bone plate when fixating fractures of this considered type. Two design parameters are varied for the bone plate design during the optimization analysis. The analysis determined that a strut style poly-L-lactide-co-DL-lactide plate of 690 mm2 can provide as much mechanical stability as a similar titanium design structure of 172 mm2. The model has determined a bioabsorbable bone plate design that is as strong as a titanium plate when fixating fractures of the load-bearing mandible. This is an intriguing outcome, considering that the polymer material has only 6% of the stiffness of titanium.

Research paper thumbnail of Comparison of Plate-Screw Systems Used in Mandibular Fracture Reduction: Finite Element Analysis

Journal of Biomechanical Engineering, 2006

A finite element model of the human dentate mandible has been developed to provide a comparison o... more A finite element model of the human dentate mandible has been developed to provide a comparison of fixation systems used currently for fracture reduction. Volume domains for cortical bone, cancellous bone, and teeth were created and meshed in ANSYS 8.0 based on IGES curves created from computerized tomography data. A unilateral molar clench was loaded on the model with a fracture gap simulated along the symphysis. Results based on Von Mises stress in cortical and cancellous bone surrounding the screws, and on fracture surface spatial fixation, show some relative differences between different screw-plate systems, yet all were judged to be appropriate in their reduction potential.

Research paper thumbnail of The Effects of Frictionless/Frictional Contact Boundary Conditions in Finite Element Modeling of Mandibular Fractures

Multidiscipline Modeling in Materials and Structures, 2008

Finite element (FE) modeling of the human dentate mandible is the method of choice currently used... more Finite element (FE) modeling of the human dentate mandible is the method of choice currently used for simulating structural fracture analyses in the mandibular region. A finite element model of a parasymphyseal fracture with an internal rigid fixation plate-screw system has been developed to compare the effects of including frictionless/frictional contact boundary conditions at the fracture site. It is common

Research paper thumbnail of Salvage of partial facial soft tissue avulsions with medicinal leeches

Otolaryngology-head and Neck Surgery, 2004

BACKGROUND: Medicinal leeches have been demonstrated to be extremely useful and safe in the salva... more BACKGROUND: Medicinal leeches have been demonstrated to be extremely useful and safe in the salvage of venous outflow compromised tissue, particularly in digit replants and various forms of flaps. OBJECTIVE: To demonstrate the utility of medicinal leeches in the salvage of venous outflow-compromised traumatic soft tissue avulsions in key facial structures. METHODS: A retrospective review of 4 cases involving the external ear, nose, lip, and scalp in which apparent venous outflow compromise was present. Medicinal leeches were applied acutely in each of these 4 cases, salvaging each of the partially avulsed soft tissue segments. RESULTS: Complete or near complete salvage of each soft tissue segment after using medicinal leeches. CONCLUSIONS: Although it is unusual for a partial soft tissue avulsion of the face to require medicinal leech therapy, situations may occur in which there is adequate arterial inflow but inadequate venous outflow. In such cases, medicinal leeches may play a very important role in salvaging the soft tissue segment. This is particularly important in vital structures such as the ear, nose, lip, and eyelid in which acute or secondary reconstruction is complex. EBM rating: C.

Research paper thumbnail of Biomechanical Optimization of Bone Plates Used in Rigid Fixation of Mandibular Symphysis Fractures

Journal of Oral and Maxillofacial Surgery, 2010

To design and optimize a bone plate for fractures of the mandibular symphysis that will provide m... more To design and optimize a bone plate for fractures of the mandibular symphysis that will provide maximum fracture stability with minimal implanted volume and patient intrusion. The design will be driven by the unique biomechanics specific to this fracture location. A finite element model of a fractured human mandible was created using computed tomography scans. The boundary conditions included simulating molar, canine, and incisal loading. The bone plate design process included a shape optimization routine and design parameter analysis using the model. The optimized bone plate design was finally compared with standard bone plate configurations according to stress and strain measures. Compared with the miniplate combination, the InterFlex III plate, with the same thickness and just 14% more implanted volume, had only 55% of the plate stress and 25% less fracture strain under the strongest loads considered by the model. Compared with the band/fracture plate combination, the InterFlex plate had 88% of the fracture strain and 74% of the plate stress, despite having only 60% of the plate volume. The results have demonstrated that the new optimized plate is a hybrid of fixation hardware with the small profile of the smallest miniplate configuration and the superior fixation strength and safety that exceeds that of the larger fracture plate configuration.

Research paper thumbnail of Mandibular defect reconstruction utilizing preoperative 3D modeling, plate pre-bending and a novel triad graft: a case report

Stomatological Disease and Science, 2017

The reconstruction of boney defects of the mandible are a challenge in surgical therapy despite a... more The reconstruction of boney defects of the mandible are a challenge in surgical therapy despite advances in bone grafting. This case study details a 30-year-old female who sustained a gunshot wound to the mandible leaving a 5 cm boney defect. This defect was reconstructed utilizing preoperative three-dimensional (3D) planning, an accurately pre-bent reconstruction plate, and a novel "triad" construct of autogenous bone graft, demineralized bone matrix, and an osteoprotective membrane. This reconstruction workflow allowed maintenance of the contour of the mandible and bone regeneration while also acting as a barrier to other tissues. This new technique reduced operative donor site morbidity and decreased surgical time dramatically, allowing the patient to be discharged the same day. The patient has a 5-year follow-up with panorex film and a biopsy of the graft area showing normal cortical bone. This case report illustrates the combination of advanced technology and novel products which can decrease operating time, decrease anesthesia time, increase precision, and most importantly decrease patient morbidity.

Research paper thumbnail of Experimental and Numerical Modeling of Screws Used for Rigid Internal Fixation of Mandibular Fractures

Modelling and Simulation in Engineering, 2008

Experimental and numerical methods are used to explore the stresses generated around bone screws ... more Experimental and numerical methods are used to explore the stresses generated around bone screws used in rigid internal fixation of mandibular fractures. These results are intended to aid in decisions concerning both the design and the use of these bone screws. A finite element (FE) model of a human mandible is created with a fixated fracture in the parasymphyseal region. The mandibular model is anatomically loaded, and the forces exerted by the fixation plate onto the simplified screws are obtained and transferred to another finite element submodel of a screw implant embedded in a trilaminate block with material properties of cortical and cancellous bone. The stress in the bone surrounding the screw implant is obtained and compared for different screw configurations. The submodel analyses are further compared to and validated with simple axial experimental and numerical screw pull-out models. Results of the screw FE analysis (FEA) submodel show that a unicortical screw of 2.6 mm ma...

Research paper thumbnail of Effects of Topical Copper Tripeptide Complex on CO2 Laser–Resurfaced Skin

Archives of Facial Plastic Surgery, 2006

To evaluate the role of skin care products that contain a copper tripeptide complex, glycyl-L-his... more To evaluate the role of skin care products that contain a copper tripeptide complex, glycyl-L-histidyl-L-lysine-Cu 2ϩ (GHK-Cu), in treating carbon dioxide (CO 2) laser-resurfaced skin. Methods: Patients meeting the inclusion criteria underwent circumoral skin resurfacing using a CO 2 laser at standard settings. Patients were then randomized to receive posttreatment skin regimens with or without GHK-Cu. Evaluations for erythema throughout the posttreatment period were performed using computer software and blinded evaluators. In addition, overall improvement in wrinkles and overall improvement in skin appearance 12 weeks after treatment were assessed. Patients completed a validated questionnaire before and 12 weeks after treatment. Results: Thirteen patients completed the study. Computer analysis and blinded evaluators found no statistically significant differences between groups for earlier resolution of erythema. All the patients experienced significant improvement in wrinkles and overall skin quality, but no differences were found between groups. The results of the questionnaire indicated a significant difference in the posttreatment improvement of overall skin quality for patients using GHK-Cu (P =.04). Conclusions: Copper tripeptide complex (GHK-Cu) skin care products placed on CO 2 laser-resurfaced skin offered no significant reduction or resolution of posttreatment erythema. Objective evaluation found no significant improvement in wrinkles or overall skin quality. However, patient satisfaction was significantly higher for those who used GHK-Cu skin care products after CO 2 laser skin resurfacing.

Research paper thumbnail of Reviews from Current Literature

Journal of Oral Implantology, 1998

Research paper thumbnail of Osteosynthesis plate, method of customizing same, and method for installing same

Research paper thumbnail of The Effects of Frictionless/Frictional Contact Boundary Conditions in Finite Element Modeling of Mandibular Fractures

Multidiscipline Modeling in Materials and Structures, 2008

Finite element (FE) modeling of the human dentate mandible is the method of choice currently used... more Finite element (FE) modeling of the human dentate mandible is the method of choice currently used for simulating structural fracture analyses in the mandibular region. A finite element model of a parasymphyseal fracture with an internal rigid fixation plate-screw system has been developed to compare the effects of including frictionless/frictional contact boundary conditions at the fracture site. It is common

Research paper thumbnail of Dog Bites of the Scalp, Face, and Neck in Children

The Laryngoscope, 2003

To update the surgical management of injuries from dog bites of the scalp, face, and neck in chil... more To update the surgical management of injuries from dog bites of the scalp, face, and neck in children. Retrospective case review. A retrospective review of 44 children with dog bites of the scalp, face, and neck was carried out at the University of New Mexico Health Sciences Center (Albuquerque, NM) between January 1, 1995, and December 31, 2000. Data on demographics, hospitalization, surgery, and outcome were collected and entered into an Access 2000 database. The children ranged in age from 1.0 to 12.1 years. The mean age of the study population was 5.2 years (+/-2.9 y standard deviation). Sixteen severely injured children (36%) were hospitalized to repair damage to the airway and blood vessels of the neck or to treat hemodynamic compromise. The length of stay in hospital ranged from 1 to 16 days. The most common injury in these children was a scalp laceration (57%). Twenty-six less severely injured children (64%) were not hospitalized. The most common surgery in these children (88%) was repair of multiple facial lacerations. Attention deficit hyperactivity disorder was noted in the medical records of 12 children (29%). Complications occurred in five children (31%) who were hospitalized and nine children (35%) who were not hospitalized. The injured child is typically a 5-year-old boy attacked by a familiar dog at home or in the local neighborhood. Children with the diagnosis of attention deficit hyperactivity disorder appear to be at a higher risk of dog bite injuries and should be monitored during interactions with dogs. The goal of surgical management for severely injured children is to avoid immediate mortality and to establish a schedule of multiple-staged procedures for revision surgeries. An optimal cosmetic result is the principal goal for less severely injured children.

Research paper thumbnail of Modeling of Screw-Plate Systems for Mandibular Fracture Repair

Advances in Bioengineering, 2004

Fractures of the mandible are a common form of traumatic injury. These fractures may be repaired ... more Fractures of the mandible are a common form of traumatic injury. These fractures may be repaired using miniplates secured to cortical bone with screws. In the present research, the authors measure the pull-out strengths of cortical screws using a standard test paradigm and develop a ...

Research paper thumbnail of The Effects of Varying Frictional Contact Boundary Conditions in Finite Element Analysis of Mandibular Parasymphyseal Fracture

ASME 2007 Summer Bioengineering Conference, 2007

This paper describes a technical assessment of operating Interprovincial Pipe Line Inc.'s reactiv... more This paper describes a technical assessment of operating Interprovincial Pipe Line Inc.'s reactivated Line 1 segments from Hardisty, Alberta to Regina, Saskatchewan and active Line 13 segments from Regina to Gretna, Manitoba at a maximum operating pressure equivalent to 80 percent of the test pressure. The assessment addressed the metallurgy and manufacturing methods of the pipe materials, the operating history, the hydrostatic test results, and the analysis of the hydrostatic test failures. From the assessment it was concluded that the existing portions of original Line 1 and all of existing Line 13 that will be used as parts of the proposed New Line 13 are capable of being operated at pressure levels of 80 percent of the 1993/1994 test pressures.

Research paper thumbnail of Finite Element Analysis of Fixation Plates for Mandibular Fracture Stabilization

Plastic and Reconstructive Surgery, 2005

Wolters Kluwer Health may email you for journal alerts and information, but is committed to maint... more Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining your privacy and will not share your personal information without your express consent. For more information, please refer to our Privacy Policy. ... Skip Navigation Links Home > ...

Research paper thumbnail of Salvage of partial facial soft tissue avulsions with medicinal leeches

Otolaryngology - Head and Neck Surgery, 2004

BACKGROUND: Medicinal leeches have been demonstrated to be extremely useful and safe in the salva... more BACKGROUND: Medicinal leeches have been demonstrated to be extremely useful and safe in the salvage of venous outflow compromised tissue, particularly in digit replants and various forms of flaps. OBJECTIVE: To demonstrate the utility of medicinal leeches in the salvage of venous outflow-compromised traumatic soft tissue avulsions in key facial structures. METHODS: A retrospective review of 4 cases involving the external ear, nose, lip, and scalp in which apparent venous outflow compromise was present. Medicinal leeches were applied acutely in each of these 4 cases, salvaging each of the partially avulsed soft tissue segments. RESULTS: Complete or near complete salvage of each soft tissue segment after using medicinal leeches. CONCLUSIONS: Although it is unusual for a partial soft tissue avulsion of the face to require medicinal leech therapy, situations may occur in which there is adequate arterial inflow but inadequate venous outflow. In such cases, medicinal leeches may play a ve...

Research paper thumbnail of Rapid 3-dimensional prototyping for surgical repair of maxillofacial fractures: a technical note

Journal of Oral and Maxillofacial Surgery, 2004

Research paper thumbnail of Assessement of Proplast-Teflon disc replacements

Journal of Oral and Maxillofacial Surgery, 1990

Research paper thumbnail of Infection Rates Following Perioperative Prophylactic Antibiotics Versus Postoperative Extended Regimen Prophylactic Antibiotics in Surgical Management of Mandibular Fractures

Journal of Oral and Maxillofacial Surgery, 2009

Purpose: To determine whether or not an extended regimen of prophylactic antibiotics following ei... more Purpose: To determine whether or not an extended regimen of prophylactic antibiotics following either open or closed reduction of mandibular fractures is beneficial in lowering the rate of infection in post-operative patients. Patients and Methods: This study is a retrospective chart review of 150 patients treated operatively for both complicated and uncomplicated mandibular fractures at

Research paper thumbnail of Finite Element Analysis of Screw-Plate Systems for Fixation of Parasymphyseal Fractures of the Mandible

Journal of Mechanics, 2007

Finite Element Modeling was used to compare the efficacy of common screw-plate configurations use... more Finite Element Modeling was used to compare the efficacy of common screw-plate configurations used for fixation of parasymphyseal fractures of the mandible. Measures of Von Mises stress on the screw bone interface, as well as principal strain in the reduced fracture region, were used in this comparison. This study also explored differences between orthotropic and isotropic modeling practices and compared the effect of mastication forces on both the fractured and intact halves of the mandible. The results of this analysis showed no major differences between configurations from a mechanistic point of view. This suggests that the use of any of the studied screw-plate configurations will not increase chances for post-operative complications. Furthermore, little difference is seen between analyses with either orthotropic or isotropic material properties. The inclusion of orthotropic properties can thus be avoided in future studies with similar boundary and plating conditions. Mastication...

Research paper thumbnail of Mechanical Design Optimization of Bioabsorbable Fixation Devices for Bone Fractures

Journal of Craniofacial Surgery, 2009

Bioabsorbable bone plates can eliminate the necessity for a permanent implant when used to fixate... more Bioabsorbable bone plates can eliminate the necessity for a permanent implant when used to fixate fractures of the human mandible. They are currently not in widespread use because of the low strength of the materials and the requisite large volume of the resulting bone plate. The aim of the current study was to discover a minimally invasive bioabsorbable bone plate design that can provide the same mechanical stability as a standard titanium bone plate. A finite element model of a mandible with a fracture in the body region is subjected to bite loads that are common to patients postsurgery. The model is used first to determine benchmark stress and strain values for a titanium plate. These values are then set as the limits within which the bioabsorbable bone plate must comply. The model is then modified to consider a bone plate made of the polymer poly-L/DL-lactide 70/30. An optimization routine is run to determine the smallest volume of bioabsorbable bone plate that can perform and a titanium bone plate when fixating fractures of this considered type. Two design parameters are varied for the bone plate design during the optimization analysis. The analysis determined that a strut style poly-L-lactide-co-DL-lactide plate of 690 mm2 can provide as much mechanical stability as a similar titanium design structure of 172 mm2. The model has determined a bioabsorbable bone plate design that is as strong as a titanium plate when fixating fractures of the load-bearing mandible. This is an intriguing outcome, considering that the polymer material has only 6% of the stiffness of titanium.

Research paper thumbnail of Comparison of Plate-Screw Systems Used in Mandibular Fracture Reduction: Finite Element Analysis

Journal of Biomechanical Engineering, 2006

A finite element model of the human dentate mandible has been developed to provide a comparison o... more A finite element model of the human dentate mandible has been developed to provide a comparison of fixation systems used currently for fracture reduction. Volume domains for cortical bone, cancellous bone, and teeth were created and meshed in ANSYS 8.0 based on IGES curves created from computerized tomography data. A unilateral molar clench was loaded on the model with a fracture gap simulated along the symphysis. Results based on Von Mises stress in cortical and cancellous bone surrounding the screws, and on fracture surface spatial fixation, show some relative differences between different screw-plate systems, yet all were judged to be appropriate in their reduction potential.

Research paper thumbnail of The Effects of Frictionless/Frictional Contact Boundary Conditions in Finite Element Modeling of Mandibular Fractures

Multidiscipline Modeling in Materials and Structures, 2008

Finite element (FE) modeling of the human dentate mandible is the method of choice currently used... more Finite element (FE) modeling of the human dentate mandible is the method of choice currently used for simulating structural fracture analyses in the mandibular region. A finite element model of a parasymphyseal fracture with an internal rigid fixation plate-screw system has been developed to compare the effects of including frictionless/frictional contact boundary conditions at the fracture site. It is common

Research paper thumbnail of Salvage of partial facial soft tissue avulsions with medicinal leeches

Otolaryngology-head and Neck Surgery, 2004

BACKGROUND: Medicinal leeches have been demonstrated to be extremely useful and safe in the salva... more BACKGROUND: Medicinal leeches have been demonstrated to be extremely useful and safe in the salvage of venous outflow compromised tissue, particularly in digit replants and various forms of flaps. OBJECTIVE: To demonstrate the utility of medicinal leeches in the salvage of venous outflow-compromised traumatic soft tissue avulsions in key facial structures. METHODS: A retrospective review of 4 cases involving the external ear, nose, lip, and scalp in which apparent venous outflow compromise was present. Medicinal leeches were applied acutely in each of these 4 cases, salvaging each of the partially avulsed soft tissue segments. RESULTS: Complete or near complete salvage of each soft tissue segment after using medicinal leeches. CONCLUSIONS: Although it is unusual for a partial soft tissue avulsion of the face to require medicinal leech therapy, situations may occur in which there is adequate arterial inflow but inadequate venous outflow. In such cases, medicinal leeches may play a very important role in salvaging the soft tissue segment. This is particularly important in vital structures such as the ear, nose, lip, and eyelid in which acute or secondary reconstruction is complex. EBM rating: C.