gp130 is important for the normal morphogenesis of Meckel's cartilage and subsequent mandibular development

gp130-mediated signaling is involved in both chondrogenesis and osteogenesis, but its direct role in the formation of embryonic Meckel's cartilage and associated mandibular development has not yet been elucidated. In this study, we examined the influence of gp130 ablation on the developing mandibular Meckel's cartilage by evaluating the morphological and histological changes as well as the gene expression patterns in developing embryonic gp130-/- mice. The ablation of the gp130 gene showed no change in region-specific collagen mRNA expression except for a slight delay in its expression but caused shortened embryonic Meckel's cartilage, delayed hypertrophic chondrocyte maturation and subsequent bony replacement with characteristic bending of the intramandibular Meckel's cartilage. The bending of Meckel's cartilage led to a narrow mandibular arch at the rostral area with poor cortical plate formation. These findings indicate that gp130-mediated signaling is important for the normal morphogenesis of Meckel's cartilage and subsequent mandibular development.

Closed Reduction of Mallet Fractures using Extension Black Kirshner Wire / 대한정형외과학회잡지

Operative repair of mallet fracture is a technically difficult operation because fracture of fragment and the difficulty in visualizing the articular congruity. The problems with these methods include soft tissue scar formation and subsequent joint stiffness. From January 1993 to April 1994, eight cases of mallet fingers with displaced large fracture fragment and/or subluxed distal phalanx were treated by closed reduction using extension-block Kirschner wire. The follow-up evaluation took place after a mean of 6 months. The results according to Crawford's criteria were four excellent, two good and two fair. This technique is simple, and easier than other techniques for reduction of mallet fractures, and is associated with a low morbidity.