Diseño y fabricación de un nuevo distractor curvo de sínfisis mandibular para transporte óseo / Design and manufacture of a new curve symphyseal distractor for mandibular bone transport

Son activados principalmente por el operador diariamente; teniendo como ventaja estos últimos la ausencia de cicatrices cutáneas permanentes. El objetivo principal de este estudio fue diseñar y fabricar un prototipo de distractor curvo de sínfisis, intraoral para reconstrucción mandibular. Materiales y Métodos: Se realizaron pruebas técnicas: modelo elementos finitos del distractor y cuerpo mandibular, generando una malla formada por 80.000 elementos con restricciones en el condilo mandibular, dos tornillos a cada lado de la placa y cuatro a cada lado del distractor en todos los grados de libertad; se aplicaron fuerzas de 248N a la zona. Finalmente, se realizó la prueba de instalación en cadáver para verificar la técnica quirúrgica y su ergonomía. Resultados: Se observó una distribución uniforme de esfuerzos para todo el sistema mandíbula- distractor, garantizando su resistencia y estabilidad estructural. Conclusiones: El dispositivo es resistente a las fuerzas de masticación, es de facial instalación y activación; permite la reconstrucción de segmentos curvos de amplia longitud.

Introduction and Objective: Currently, there are extra-and intra devices, which are mainly triggered by the operator daily, taking advantage as the latter no permanent scars skin. The main objective of this study was to design and manufacture a prototype of intraoral curve symphyseal distractor for mandibular reconstruction. Materials and Methods: The following technical tests were carried out: finite element model of the distractor and mandibular body creating a net of 80,000 elements with restrictions in the mandibular condyle, two screws on each side of the plate and four on each side of the distractor in every degree of freedom. 248N forces were applied to the zone. Finally, the installation test on a cadaver was done in order to verify the surgical technique and its ergonomy. Results: A uniform distribution of strains was observed for all the mandibular-distractor system, guarantying its resistance and structural stability. Conclusions: The device is resistant to masticatory forces; it is easy to install and to activate and allows the reconstruction of wide range curved segments.

Three cases of symphysis pubis separation associated with delivery / 영남의대학술지

Symphysis pubis separation is an uncommon but not rare complication of delivery. Characteristic symptoms of symphyseal separation include suprapubic pain and tenderness which radiate to the back or legs, difficult ambulation, and bladder dysfunction. Clinical history, presenting symptoms, and response to therapy are sufficient to make the diagnosis, although radiographic documentation of symphyseal separation by x-ray or ultrasound are frequently used to confirm the diagnosis. The underlying etiology of symptomatic symphyseal separation has not been fully elucidated. Associations with macrosomia, pathological joint loosening, and increased force placed on the pelvic ring have been suggested as possible etiologies. Conservative therapy, including bed rest, pelvic binders, ambulation devices, and mild analgesics usually result in complete recovery within 4-16 weeks. Our experience of three cases of peripartum symphysis pubis separation delivered from 1998 to 1999 were reviewed with related articles.