Recombinant human bone morphogenic protein-2 Induces the Differentiation and Mineralization of Osteoblastic Cells Under Hypoxic Conditions via Activation of Protein Kinase D and p38 Mitogen-Activated Protein Kinase Signaling Pathways

Hypoxia suppresses osteoblastic differentiation and the bone-forming capacity. As the leading osteoinductive growth factor used clinically in bone-related regenerative medicine, recombinant human bone morphogenic protein-2 (rhBMP- 2) has yielded promising results in unfavorable hypoxic clinical situations. Although many studies have examined the effects of rhBMP-2 on osteoblastic differentiation, mineralization and the related signaling pathways, those of rhBMP-2 on osteoblastic cells remain unknown, particularly under hypoxic conditions. Therefore, this study was conducted under a 1% oxygen tension to examine the differentiating effects of rhBMP-2 on osteoblastic cells under hypoxia. rhBMP-2 could also induce the differentiation and mineralization of Osteoblastic (MC3T3-E1) cells under1%hypoxic conditions. rhBMP-2 could also induce the differentiation and mineralization of MC3T3-E1 cells under 1% hypoxic conditions. rhBMP-2 increased the alkaline phosphatase {ALP} activity in a time dependent manner, and expression of ALP, collagen type-1 (Col-1) and osteocalcin (OC) mRNAwere up-regulated significantly in a time- and concentration-dependent manner. In addition, the area of the mineralized nodules increased gradually in a concentration-dependent manner. Western blot analysis, which was performed to identify the signaling pathways underlying rhBMP-2-induced osteoblastic differentiation under hypoxic conditions, showed that rhBMP-2 significantly promoted the phosphorylation of the p38 mitogen-activated protein kinase (MAPK) in a time-dependent manner. A pretreatment with SB203580, a p38 MAPK inhibitor, inhibited the rhBMP-2-mediated differentiation and mineralization. Moreover, the phosphorylation of p38 induced by rhBMP-2 was inhibited in response to a pretreatment of the cells with Go6976, a protein kinase D {PKD) inhibitor. These findings suggest that rhBMP-2 induces the differentiation and mineralization of MC3T3-E1 cells under hypoxic conditions via activation of the PKD and p38 MAPK signaling pathways.

Sequential treatment for a patient with hemifacial microsomia: 10 year-long term follow up / 대한악안면성형재건외과학회지

Hemifacial microsomia (HFM) is the most common craniofacial anomaly after cleft lip and cleft palate; this deformity primarily involves the facial skeleton and ear, with either underdevelopment or absence of both components. In patients with HFM, the management of the asymmetries requires a series of treatment phases that focus on their interception and correction, such as distraction osteogenesis or functional appliance treatment during growth and presurgical orthodontic treatment followed by mandibular and maxillary surgery. Satisfactory results were obtained in a 9-year-old girl with HFM who was treated with distraction osteogenesis. At the age of 19, genioplasty and mandible body augmentation with a porous polyethylene implant (PPE, Medpor(R), Porex) was sequentially performed for the functional and esthetic reconstruction of the face. We report a case of HFM with a review of the literature.

Erratum to: Sequential treatment for a patient with hemifacial microsomia: 10 year-long term follow up / 대한악안면성형재건외과학회지

"Acknowledgements" section should be inserted in this article.

Effect of hepatocyte growth factor on the repair of defect in the articular disc in rabbit temporomandibular joint

Clinical Study Of Odontogenic Keratocyst

PURPOSE: The purpose of this study is to investigate the clinical and histological features of odontogenic keratocyst PATIENTS AND METHODS: A retrosective review of 100 patients who were diagnosed as odontogenic keratocyst by hitological findings during the period of January 2000 and December 2005 in the Dept. of Oral and Maxillofacial surgery Pusan National University was consecuted. For each patient, age, sex, location of lesion, initial diagnosis by radiographic features, treatment procedure, hitologic findings and recurrance rate were evaluated. RESULTS: In this study, OKC has male prevalance to female by 1.38:1, and most likely occurs during third decade. The most common site of lesion was mandibular ramus region(34.6%) and the most common symptom was swelling(50%). The most common initial diagnosis by radiographic findings was OKC and cyst enucleation was the most common treatment method. The recurrance rate was 28% and existence of daugther cyst is thought to be most convincing factor for prediction of recurrence. CONCLUSION: In this study, total recurrence rate was 28% and existence of daugther cyst is thought to be most convincing factor for prediction of recurrence. But, since 97% of patients were treated by enucleation and adjuntive excision, further styudy is need about concordance of recurrence rate with surgical method.