ABSTRACT
INTRODUCTION: Stability in orthognathic surgery is nowadays considered as efficient and adequate. The objective of this study was to determine and to compare the mechanical resistance to vertical load of a Le Fort I advancement osteotomy stabilized by mean of two different osteosynthesis techniques, one using two 10-hole pre-bent T-shaped plates, the other using four manually bent 4-hole L- and J-shaped plates. MATERIEL AND METHODS: Standardized Le Fort I advancement osteotomies have been made on polyurethane models. The maxillary advancement was 5mm. Two groups of five models each were created. Group 1 was stabilized by mean of two 10-hole pre-bent T-shaped plates fixed by monocortical screws in the paranasal region. Group 2 was stabilized by mean of manually bent four 4-hole L-shaped plates fixed monocortical screws in the zygomatic and paranasal regions. A testing machine was used to load vertically the models at the range of 1mm/min linear displacement until peak load and system failure. Statistical analysis was realized using ANOVA and t-test, considering P as significant if <0.005. RESULTS: The maximal tolerated load was 15N in group 1and 42.71N in group 2 (P=0.003). DISCUSSION: The use of two T-shaped 10-holes pre-bent plates allows for less resistance in vertical loading than the use of four 4-holes manually bent L-shaped plates.
Subject(s)
Bone Plates , Fracture Fixation, Internal , Osteotomy, Le Fort , Stress, Mechanical , Bone Plates/adverse effects , Bone Screws/adverse effects , Equipment Design , Equipment Failure , Equipment Failure Analysis , Fracture Fixation, Internal/instrumentation , Fracture Fixation, Internal/methods , Humans , In Vitro Techniques , Materials Testing/methods , Mechanical Phenomena , Models, Anatomic , Osteotomy, Le Fort/instrumentation , Osteotomy, Le Fort/methodsABSTRACT
El objetivo de esta investigación fue comparar la respuesta tisular en defectos tratados con matriz óseo de origen bovino y humano. Se realizó un estudio descriptivo con 12 conejos en los cuales se confeccionaron dos defectos en la calota craneana de acuerdo a procesos convencionales. Cada defecto fue aleatoriamente rellenado con matriz ósea bovina o con matriz ósea humana; se realizaron evaluaciones histológicas a las 7 y 15 semanas de realizada la cirugía (6 animales en cada grupo). A las 7 semanas se identificó un leve infiltrado inflamatorio y claras diferencias entre el hueso periférico y el sitio injertado, mientras que a las 15 semanas se observo la persistencia de algunas partículas injertadas y la presencia de hueso nuevo formado en el defecto; no se logró identificar diferencias en la secuencia de reparación o retrasos en la misma con ninguno de los dos materiales. Se concluye que ambos materiales son útiles en la regeneración ósea en el presente modelo experimental.
The aim of this research was to compare the tissue response in treated defects with bone matrix with bovine or human origin. Was realized a descriptive study with 12 rabbits where was executed two defects in the skull in relation to conventional techniques. Randomized defects were used to put bone matrix with bovine or human origin; histological exam was realized in the week number 7 and 15 with 6 animals each. At 7 weeks was observed a limited inflammatory infiltrate with clear differences between the peripheral bone and the filled bone and in the 15 weeks of analysis was observed the presence of some particulate of the bone graft beside a new bone into the defect; was not observed any differences in the sequence of repair or delayed in the bovine or human material. It´s concluded that both materials are useful in bone regeneration for this experimental model.
Subject(s)
Humans , Animals , Male , Cattle , Rabbits , Biocompatible Materials , Bone Regeneration/physiology , Bone Substitutes/therapeutic use , Bone Transplantation/methods , Bone MatrixABSTRACT
Electrical stimulation has been used in different conditions for tissue regeneration. The aim of this study was to analyze the tissue response of defects created in rabbit skulls to electrical stimulation. Two groups were formed, each with 9 New Zealand rabbits; two 5 mm defects were made, one in each parietal, with one being randomly filled with autogenous bone extracted as particles and the other maintained only with blood clotting. The rabbits were euthanized at 8 weeks and 15 weeks to then study the samples collected histologically. In the 8-week analysis bone formation was observed in the defects in the test and control filled with bone graft, whereas the defects with clotting presented a very early stage of bone formation with abundant connective tissue. At 15 weeks an advanced stage of bone regeneration was identified in the defects with bone graft, whereas no significant differences were found in the electrically stimulated defects. In conclusion, electrical stimulus does not alter the sequence of bone formation; new studies could help establish patterns and influences of the stimulus on bone regeneration.
La estimulación eléctrica ha sido empleada en diferentes condiciones para la regeneración de tejidos. El objetivo de esta investigación es analizar la respuesta tisular de defectos creados en cráneo de conejos a la estimulación eléctrica. Se formaron 2 grupos con 9 conejos de raza New Zealand cada uno; en ellos se realizaron dos defectos de 5 mm, uno en cada parietal, siendo aleatoriamente uno rellenado con el propio hueso autógeno extraído en forma de partículas y el otro mantenido solo con coagulo sanguíneo; se realizó la eutanasia a las 8 semanas y a las 15 semanas para luego estudiar histológicamente las muestras recolectadas. En el análisis de 8 semanas se observó formación ósea en los defectos test y control rellenados con injerto óseo mientras que los defectos con coagulo presentaron un estado muy precoz de formación ósea, observándose abundante tejido conectivo. A las 15 semanas se identificó un estado avanzado de regeneración ósea en los defectos con injerto óseo, donde no se apreció diferencias importantes en los defectos estimulados eléctricamente. Se concluye que el estimulo eléctrico no altera la secuencia de formación ósea; nuevos estudios podrían contribuir a establecer patrones e influencias del estimulo eléctrico en la regeneración ósea.
Subject(s)
Animals , Rabbits , Bone Regeneration/physiology , Electric Stimulation Therapy/methods , Skull/pathology , Skull/surgery , Bone Transplantation , Time FactorsABSTRACT
Electrical stimulation has been used in different conditions for tissue regeneration. The aim of this study was to analyze the tissue response of defects created in rabbit skulls to electrical stimulation. Two groups were formed, each with 9 New Zealand rabbits; two 5 mm defects were made, one in each parietal, with one being randomly filled with autogenous bone extracted as particles and the other maintained only with blood clotting. The rabbits were euthanized at 8 weeks and 15 weeks to then study the samples collected histologically. In the 8-week analysis bone formation was observed in the defects in the test and control filled with bone graft, whereas the defects with clotting presented a very early stage of bone formation with abundant connective tissue. At 15 weeks an advanced stage of bone regeneration was identified in the defects with bone graft, whereas no significant differences were found in the electrically stimulated defects. In conclusion, electrical stimulus does not alter the sequence of bone formation; new studies could help establish patterns and influences of the stimulus on bone regeneration.
ABSTRACT
El objetivo de este estudio fue realizar un análisis retrospectivo de la etiología, incidencia, uso de dispositivos de seguridad, tipo y severidad de las fracturas, tratamiento y complicaciones de los traumatismos del tercio medio facial en una población pediátrica e adolescente del Estado de São Paulo. La muestra fue seleccionada a partir del análisis de historias clínicas de 2986 pacientes víctimas de traumatismos faciales atendidos entre 1999 y 2008 por el Área de Cirugía Buco-Maxilo-Facial de la Facultad de Odontología de Piracicaba, Universidad Estatal de Campinas, Estado de São Paulo-Brasil. Durante este periodo, 757 pacientes menores de 18 años fueron víctimas de traumatismos maxilofaciales. De éstos, 138 pacientes presentaron 148 fracturas nasales y de tercio medio. Los adolescentes fueron el grupo etario más afectado, mientras que el género masculino fue el de mayor prevalencia. Los accidentes ciclísticos se constituyeron en la principal etiología (21.7%). El tratamiento conservador fue utilizado en la gran mayoría de los casos (118 pacientes, 85.5%). Veinte pacientes (14.5%) recibieron tratamiento quirúrgico y solo un caso de complicación pos-operatoria fue reportado. La incidencia de traumatismos y fracturas del tercio medio fue alta en la región de estudio. Los accidentes ciclísticos y las agresiones físicas fueron los principales factores etiológicos, siendo el género masculino predominante en todos los grupos etarios evaluados. Las fracturas nasales y del complejo zigomático orbitario fueron las más prevalentes, mientras que el tratamiento conservador fue instituido en la gran mayoría de los casos
This study showed a retrospective analysis of the etiology, incidence, use of safety devices, type and severity of fractures, treatment and complications of midface trauma in a pediatric and adolescent population of São Paulo - Brazil. We analyzed 2986 medical records of facial trauma patients treated by the Division of Oral and Maxillofacial Surgery Piracicaba Dental School, State University of Campinas, São Paulo - Brazil between 1999 and 2008. During this period, 757 patients under 18 were identified and 138 had 148 nasal and midface fractures. The adolescents were the most affected age group, male gender being the most prevalent. The most common injury causes were bicycle accident (21.74%) and violence (19.6%). Conservative treatment was used in the majority of cases (118 patients, 85.5%). Twenty patients (14.5%) received surgical treatment and only one case of postoperative complication was reported. The incidence of trauma and middle third fractures in pediatric and adolescents patients was high in the study area, being the main etiological factors the bicycle accidents and violence. The male were most affected in all age groups tested. Nasal fractures and zygomatic complex were most prevalent, while conservative treatment was instituted in most cases
Subject(s)
Humans , Male , Adolescent , Female , Child, Preschool , Child , Maxillary Fractures/therapy , Pediatric Dentistry/methods , Facial Injuries/etiology , Facial Injuries/therapy , Maxillofacial Injuries/therapy , Dental Care for Children/methodsABSTRACT
OBJECTIVE: This study showed a retrospective analysis of the etiology, incidence and treatment of maxillofacial injuries in a pediatric and adolescent population of the State of Sao Paulo. METHODS: We analyzed 2986 medical records of victims of facial trauma under 18 years, treated between 1999 and 2008 by the Department of Oral and Maxillofacial Surgery, Piracicaba Dental School, University of Campinas, Sao Paulo - Brazil. During this period, 757 patients under 18 were victims of maxillofacial trauma, of which, 112 patients had 139 lines of fracture in the mandible. The most affected age group were male adolescents. RESULTS: The bicycle accidents constituted the main etiology (34.82%). The conservative treatment was used in 51% of cases, and 49% received surgical treatment. Only 5 cases of postoperative complications were identified. CONCLUSION: The incidence of trauma and mandible fractures in pediatric and adolescent patients was high in the area of study. Bicycle accidents and falls being the main etiological factors. The group of adolescents was most affected. The conservative and surgical treatment was used almost in the same proportion.
Subject(s)
Mandibular Fractures/epidemiology , Accidental Falls/statistics & numerical data , Adolescent , Age Distribution , Bicycling/injuries , Brazil/epidemiology , Child , Child, Preschool , Facial Bones/injuries , Female , Fracture Fixation, Internal , Humans , Infant , Infant, Newborn , Male , Mandibular Fractures/etiology , Mandibular Fractures/therapy , Postoperative Complications , Retrospective Studies , Sex DistributionABSTRACT
Objetivo. Analizar histométricamente el efecto de la matriz óseadesmineralizada de origen humana y de la resina poliuretana derivada delaceite de mamona, sobre el proceso de regeneración ósea. Diseño del estudio:fueron utilizados 24 conejos y en cada calota craniana fueron preparadasdos cavidades quirúrgicas, siendo una a cada lado de la sutura parietal.Los animales fueron divididos en dos grupos. En el grupo I la cavidadexperimental (lado derecho) fue rellenada con la poliuretana derivadadel aceite de mamona, mientras que en el grupo II la cavidad experimentalfue rellenada con la matriz ósea desmineralizada de origen humano. Lascavidades de control fueron rellenadas solo con la sangre del animal. Losanimales fueron sacrificados en los períodos postoperatorios de 04, 07 y15 semanas. Resultados. El análisis estadístico, realizado en base de losdatos de la histometría, mostró una mayor neoformación ósea de los gruposI y II en relación al grupo control, no existiendo diferencia estadísticacuando los grupos experimentales fueron comparados. Conclusiones. Eluso de poliuretana derivada del aceite de mamona y matriz ósea desmineralizadade origen humano mejoran el proceso de regeneración cuandolo comparamos a la regeneración ósea normal resultando que entre ambosmateriales tuvieron un comportamiento similar sin diferencias estadísticas significantes entre sí (AU)
Objective. The present study was aimed at carrying out a histological and histometric analysis on the effect of humande mineralized bone matrix and a polyurethane resin, derived of the castor bean oil, on the bone regeneration process. Design: For this,24 rabbits were used and in each calvarium two surgical bone defect were prepared, one on the right side and another on the left side of the parietal suture. The animals were divided into two groups. In group I the experimental defect (right side) was filled with polyurethane derived from oil of the castor oil plant, while in group II the experimental cavity was filled with demineralized bone matrix of human origin. The control cavities were just filled with the bloodof the animal. The animals were sacrificed in the postoperative period at 04, 07 and 15 weeks. Results. The statistical analysis, which was based on the data of the histometric study, showed larger bone neoformation in groups I and II in relation to the control groups, and there were no statistical differences when the experimental groups were compared. Conclusions. The use of polyurethane resinimplants and demineralized human bone matrix helped and optimized the regeneration process when compared with naturalbone regeneration, and similar behavior was obtained without statistical differences in both materials (AU)
