Estudio experimental sobre la regeneración ósea mandibular de la rata con diferentes biomateriales / Experimental study in rats of mandibular bone regeneration with different biomaterials

Objetivo. Los defectos óseos mandibulares resultantes de infecciones,traumatismos o resecciones oncológicas, van a producir severos problemas funcionalesy/o estéticos, que van a precisar de un tratamiento complejo. Durante losúltimos años, las aportaciones al terreno de la reconstrucción ósea se han debatidoentre métodos tan dispares como la distracción ósea o la utilización de colgajos libresmicrovascularizados, pasando por un sin fin de biomateriales. El objetivo de este estudiofue comparar la formación de hueso nuevo tras la aplicación de una membranareabsorbible y dos tipos de sustitutivos óseos. Material y método. Se utilizaron 24ratas adultas macho tipo Wistar, en las que se crearon defectos circulares de 4 mmde diámetro en ambos lados de la mandíbula. Se formaron 4 grupos, un grupo controly 3 grupos experimentales. Los animales fueron sacrificados a las 3 y 6 semanasde la cirugía, realizándose un análisis radiológico e histológico. Resultados. Los defectoscontrol no mostraron formación ósea, apareciendo una reparación por tejidofibroso. La membrana de hueso utilizada de forma aislada, actuó como una barreraeficaz excluyendo los tejidos no osteogénicos, pero no se produjo reparación totaldel defecto en ningún caso. El grupo de Colloss® y membrana, mostró una regeneraciónósea completa del defecto a las 6 semanas. El grupo de NovaBone® y membrana,no mostró formación ósea, apareciendo las partículas del biomaterial ocupandoel defecto. Conclusiones. La regeneración ósea fue significativamente mayoren los defectos rellenos con Colloss® y cubiertos con la membrana de Lambone®,comparado con los otros grupos experimentales(AU)

Objective. Mandibular bone defects can occur as a resultof trauma, neoplasm, or infectious conditions. Such conditions oftenare associated with severe funtional and esthetic problems. Correctivetreatment often is complicated by limitations in tissue adaptation.The aim of this study was to compare new bone formation followingapplication of a bioabsorbable membrane and two types of bonesubstitutes. Material and method. In the present study, 24 fourmonth-old male Wistar rats were used. Standardized round throughand-through bone defects (4 mm in diameter) were made in bothmandibles and the rats were divided into four groups: one controlgroup and 3 experimental groups. Animals were killed 3 and 6 weeksafter surgery. Bone defect healing was assessed by radiologic andhistologic analysis. Results. The control defects showed no boneformation; holes were filled with fibrous connective tissue. Bonemembrane alone was an efficient barrier, excluding nonosteogenictissue. However, new bone formation underneath the membranewas incomplete. The Colloss® + membrane group showed completehealing after 6 weeks. The NovaBone® + membrane group showedno bone formation and particles appeared in the defect. Conclusions.The percentage bone regeneration was significantly better in thedefects filled with Colloss® and covered with Lambone® than theother experimental groups(AU)

Osteonecrosis de los maxilares inducida por bifosfonatos: prevención y actitud terapéutica / Bisphosphonate induced osteonecrosis of the jaws: prevention and therapeutic approach

Introducción. La osteonecrosis maxilar o mandibular por bifosfonatospuede convertirse en una epidemia debido a la amplia difusión deestos fármacos entre la población.Material y método. Se muestra un protocolo para la prevención y el tratamientode esta enfermedad. Se presentan tres casos de osteonecrosismaxilar/mandibular.Resultados. Es difícil lograr una curación completa; sin embargo es posibledetener la progresión de la enfermedad.Discusión. La cirugía y la suspensión de la terapia con bifosfonatos handemostrado poca utilidad. Los antibióticos y los enjuagues con clorhexidinason las únicas medidas eficaces.Conclusiones. Es imprescindible una planificación adecuada previa a la instauracióndel tratamiento con bifosfonatos. Ante una osteonecrosis establecida,la actitud debe ser conservadora (AU)

Introduction. Bisphosphonate-induced osteonecrosis of the jaws might reach epidemic proportions due tothe widespread use of this therapy.Materials and methods. A protocol for prevention and treatmentof this pathology is shown. Three clinical cases arereported.Results. It is quite difficult to reach restitutio ad integrum,but stopping the progress of the disease is possible.Discussion. Surgical treatment and cessation of bisphosphonatetherapy are of no use. Only antibiotics and oral chlorhexidinehave shown some benefits.Conclusions. An accurate preventive attitude is mandatoryprior to undergoing bisphosphonate therapy. If osteonecrosisof the jaws is present, management should be conservative (AU)

[A study of spontaneous regeneration of defected short nerve gaps in rats]. / Estudio de la regeneración espontánea en defectos nerviosos de poca longitud en ratas.

Nerve trunk gaps can be repaired with different anastomosis methods. We investigate if spontaneous regeneration can yield results similar to artificial repair, and have compared the degree of nerve regeneration in nerve defects of extratemporal facial nerve trunk in Wistar rats. The lesions measured 4 millimeters long. Three groups were studied: 0. Normal nerve (control). 1. No treatment (therapeutic abstention). 2. Autografts. The considered parameters were: clinical outcome (degree of postoperative facial function, aspect of the defectuous region, nerve conduction latency, and number of axons that managed to penetrate the defect as well as their morphometric characteristics (nerve area). Our conclusion is that in this model placement of autografts yielded significantly better results in all the parameters studied, in spite of the scant defect length. These results likewise allow us to use this model to compare repair by means of different graft types.

[Repair of facial nerve gaps with cryopreserved allografts in rats immunosuppressed with cyclosporin A]. / Reparación de lesiones del nervio facial mediante aloinjertos criopreservados en ratas inmunodeprimidas con ciclosporina A.

UNLABELLED: The aim of this study is to assess the feasibility of peripheral nerve allografts pretreated utilizing cold storage and cyclosporin A to improve the facial nerve regeneration in Wistar rat. Three groups were designed: Normal Wistar rats. 4 millimeters nerve gaps repaired with cryopreserved nerve allografts. 4 millimeters nerve gaps repaired with cryopreserved nerve grafts and treated with cyclosporin A. At 16 weeks post-engraftment the animals were evaluated: Facial palsy grading system. Electrophysiologic latency. Axonal counting. Nervous fiber area immediately distal to the graft. The facial function of the experimental groups was similar to the control rats while the latency and morphometric parameters was poor than the normal rats. CONCLUSIONS: 1. Cryopreserved nerve allografts in facial nerve repair in rats are useful in the aquisition of a facial functional nerve recovery as much in immunosuppressed animal as not. 2. Cryopreservation of nerve allografts results a good method of storage of nerve grafts. 3. Cyclosporin A immunosuppression improved not much the grading facial palsy in this model but the electrophysiologic and morphometry is significantly better.

Reparación de lesiones del nervio facial mediante aloinjertos criopreservados en ratas inmunodeprimidas con ciclosporina A / Reparation of facial nerve gaps with cryopreserved allografts in rats immunosuppressed with ciclosporin A

El objetivo de este trabajo es comprobar el papel de la inmunodepresión con ciclosporina A en la reparación de un defecto nervioso en el tronco del nervio facial de la rata con aloinjertos criopreservados. El defecto nervioso, en el tronco extratemporal del nervio facial de la rata Wistar tenía 4 mm de longitud. Diseñamos 3 grupos:- Control normal.- Reparación con aloinjertos criopreservados.- Reparación con aloinjertos criopreservados e inmunodepresión con ciclosporina A. Métodos de evaluación de la regeneración tras 4 meses:- Grado clínico de función.- Latencia de conducción.- Contaje de axones.- Area media de las fibras nerviosas en el tronco nervioso distal al injerto. El grado de función facial en los 2 grupos reparados era muy similar al normal en cuanto a motilidad facial pero los resultados electrofisiológicos y morfométricos diferían de manera significativa respecto al nervio normal. Las conclusiones a las que llegamos fueron las siguientes:1. La utilización de aloinjertos criopreservados en animales inmunodeprimidos o no, logra la adquisición de una función facial clínicamente valorada como buena o muy buena.2. La criopreservación de injertos nerviosos alógenos resulta un proceso de almacenamiento de tejidos útil para reparar lesiones nerviosas. Los injertos así conservados llegan a alcanzar resultados clínicamente satisfactorios en el modelo que hemos utilizado.3. La inmunosupresión de ratas portadoras de aloinjertos con ciclosporina A acarrea la aparición de una función facial que mejora poco la lograda con los otros injertos en este modelo experimental. Los parámetros histológicos y morfométricos se asemejan en mayor medida a los nervios normales (AU)

The aim of this study is to assess the feasibility of peripheral nerve allografts pretreated utilizing cold storage and cyclosporin A to improve the facial nerve regeneration in Wistar rat. Three groups were designed: Normal Wistar rats. 4 millimeters nerve gaps repaired with cryopreserved nerve allografts. 4 millimeters nerve gaps repaired with cryopreserved nerve grafts and treated with cyclosporin A. At 16 weeks post-engraftment the animals were evaluated: Facial palsy grading system. Electrophysiologic latency. Axonal counting. Nervous fiber area immediately distal to the graft. The facial function of the experimental groups was similar to the control rats while the latency and morphometric parameters was poor than the normal rats. CONCLUSIONS: 1. Cryopreserved nerve allografts in facial nerve repair in rats are useful in the aquisition of a facial functional nerve recovery as much in immunosuppressed animal as not. 2. Cryopreservation of nerve allografts results a good method of storage of nerve grafts. 3. Cyclosporin A immunosuppression improved not much the grading facial palsy in this model but the electrophysiologic and morphometry is significantly better (AU)

[Gold weights for the treatment of lagophthalmos caused by facial paralysis. Our experience and review of the literature]. / Pesas de oro en el tratamiento de lagoftalmos por parálisis facial. Experiencia y revisión de la literatura.

Paralysis of the orbicularis oculi muscle in patients with facial palsy can originate serious functional and esthetic problems. The implantation of a gold weight in the upper eyelid is one of the many surgical techniques that have been described for the correction of lagophthalmos in these patients. In this article we review the literature and present our experience with gold weight implantation for eyelid reanimation in patients with facial palsy. This procedure is technically simple to perform, produces good functional and cosmetic results, has a relatively low complication rate and is reversible should facial function return.

Oral sarcoidosis with tongue involvement.

A case of oral sarcoidosis involving the tongue and buccal region is reported in a 56-year-old woman. Intraoral presentations of sarcoidosis are uncommon, and sarcoidosis of the tongue is particularly rare. In this case the tongue lesion was asymptomatic, and unusual clinical behavior. In this article, we review the clinical manifestations, diagnostic procedures, differential diagnosis and treatments of oral sarcoidosis.