A study on differentiation potency of adult stem cells from pulp, periodontal ligament, and dental follicle to osteoblast

Complex human tissues harbor stem cells and precursor cells, which are responsible for tissue development or repair. Recently, dental tissues such as dental pulp, periodontal ligament (PDL), dental follicle have been identified as easily accessible sources of undifferentiated cells. These tissues contain mesenchymal stem cells that can be differentiate into bone, cartilage, fat or muscle by exposing them to specific growth conditions. In this study, the authors procured the stem cell from pulp, PDL, and dental follicle and differentiate them into osteoblast and examine the bone induction capacity. Dental pulp stem cell (DPSC), periodontal ligament stem cell (PDLSC), and dental follicle precursor cell (DFPC) were obtained from human 3rd molar and cultured. Each cell was analyzed for presence of stem cell by fluorescence activated cell sorter (FACs) against CD44, CD105 and CD34, CD45. Each stem cell was cultured, expanded and grown in an osteogenic culture medium to allow formation of a layer of extracellular bone matrix. Osteogenic pathway was checked by alizarin red staining, alkaline phosphatase (ALP) activity test and RT-PCR for ALP and osteocalcin (OCN) gene expression. According to results from FACs, mesenchymal stem cell existed in pulp, PDL, and dental follicle. As culturing with bone differentiation medium, stem cells were differentiated to osteoblast like cell. Compare with stem cell from pulp, PDL and dental follicle-originated stem cell has more osteogenic effect and it was assumed that the character of donor cell was able to affect on differential potency of stem cell. From this article, we are able to verify the pulp, PDL, and dental follicle from extracted tooth, and these can be a source of osteoblast and stem cell for tissue engineering.

An Experimental Study Of Effect Of Intermaxillary Fixation And Occusal Splint On Pulmonary Function

Intermaxillary fixation and occusal splint are routine procedure for maxillofacial fracture and orthognathic surgery. When these methods could obstruct oral airway the patients who kept intermaxillary fixation and occusal splint in their mouth, are very difficult to breath after surgery. Nasal bleeding and pharyngeal edema due to nasotracheal intubation, residual effect of muscle relaxants, and anesthetic agent could be contributing factor of airway obstruction. In this study, pulmonary function test was evaluated before and after intermaxillary fixation, and intermaxillary fixation with occusal splint in 22 volunteers. The results were as follows 1. FVC, %FVC, FEV1, FEV1%, PEF, PEF50, MVV without intermaxillary fixtion were 4.45L, 88%, 4.03L, 90.9%, 10.26L/s, 5.53L/s, and 136.14L/min, and with intermaxillary fixation were 3.51L, 68.67%, 3.06L, 69.39L, 6.52L/s, 3.94L/s, and 69.39L/min. The results with intermaxillary fixation and occusal splint were 2.15L, 42.41%, 1.71L, 38.81%, 2.83L/s, 1.74L/s, and 37.14L/min. 2. Compared with before and after intermaxillary fixation, all values of pulmonary function test were decreased and after intermaxillary fixation and intermaixillary fixation with occulasal splint, the results were decreased. 3. MVV and PEF were decreased significantly with interaxillary fixtion and occusal splint, and FVC was less decreased. It meant that intermaxillary fixation and occluasal splint induced reduction of respiratory flow significantly, but less reduction of respiratory volume. 4. Intermaxillary fixation and occulsal splint induced increase of airway resistance, decrease of expiratory volume and air flow. So severe respiratory difficulty could be seen to all volunteers who kept intermaxillary fixtion and occusal splint. 5. In classification of respiratory difficulty, intermaxillary fixation with occulsal splint induced complex respiratory difficulty more than intermaxillary fixation only did. From the above results, doctors who care patients kept intermaxillary fixation and occusal splint should be aware of respiratory depression caused by these treatment.