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Biomedical subjects

Yin-zhong Duan

Publications and source records attributed to Yin-zhong Duan.

7 recordsLinked to original sources
PubMed2006

[Tooth movement in tissue-engineered bone].

OBJECTIVE: To explore the effect and practical value of repairing the alveolar defects with tissue engineering technique and investigate the influence of the generated new bone on the orthodontic tooth movement. METHODS: The marrow stromal cells of rats were separated, cultured in vitro and induced to osteoblast-like cells. The osteoblast-like cells were implanted onto the ceramic bovine bone. Then the complex was implanted into the alveolar defect in one side of the rat's mandible. The other side of the mandible served as control. Eight weeks later, the orthodontic appliances were placed between the first molar and incisors of SD rats to move the first molar forward. The tooth movement and root resorption of the molar were observed. RESULTS: We found that the tooth movement in the experimental area was faster than that in the normal alveolar bone (P < 0.05). The root resorption and the alveolar bone height loss were less than that in the control area (P < 0.05). CONCLUSIONS: The tissue-engineered bone did not have negative influences on tooth movement. The repair of alveolar bone defect by tissue engineering approach may be used in craniofacial surgery and orthodontics.

Animals↗
PubMed2004

[Clinical research on unilateral extraction for moderate crowding].

OBJECTIVE: To clinically investigate the results of unilateral extraction in the treatment of special moderate crowding cases. METHODS: 22 patients with harmonic profile and moderate crowding were selected and treated by unilateral extraction with Edgewise technique. The patients crowding was 6 - 9 mm and focused on one side of the arch. 22 patients with moderate crowding were treated by bilateral extraction as control. RESULTS: 22 patients have been treated successfully within 18 months. Crowding was completely resolved. Midline coincidence was basically maintained.Good intercuspation was achieved. There is no significant difference in dental arch symmetry between unilateral extraction and bilateral extraction (P > 0.05). CONCLUSION: Unilateral extraction can be successful in the treatment of special moderate crowding cases.

Adolescent↗
PubMed2004

[Cloning genes sensitive to mechanical stretch in osteoblasts through subtractive hybridization technique].

OBJECTIVE: In this experiment, genes sensitive to mechanical stretch in osteoblast like cells were cloned through subtractive hybridization technique. METHODS: Two dimensional mechanical stretch with deformation of 12% and frequency of 6 cycles was loaded on human osteoblastic like cell line Saos-2. Complementary deoxyribonucleic acid (cDNA) library of cells was constructed 12 h after loading, acting as tester. cDNA library of cells without loading was constructed, acting as driver. A subtractive cDNA library osteoblastic like cell stimulated with mechanical stretch was constructed through subtractive hybridization technique. RESULTS: Of clones randomly selected from this library, fifteen genes were identified to be the differentially expressed genes. Comparing with the sequences published in GeneBank via Internet, two sequences located in chromosome 9 and 18 respectively were identified to be novel, which were named as stretch sensitive gene 1 and stretch sensitive gene 2. CONCLUSION: It is an efficient approach to clone and study genes relative to mechanical stretch through subtractive hybridization technique.

Cell Line↗
PubMed2003

[Orthodontic treatment of malocclusion with mandibular congenital missing teeth guided by Bolton index].

OBJECTIVE: To evaluate the outcome of the treatment of malocclusion with mandibular congenital missing teeth guided by Bolton index. METHODS: 26 class I and II cases (males 10, females 16) were chosen in this study. Guided by Bolton index, enamel stripping, denture and two types of tooth extraction were used in the treatment. RESULTS: Normal Bolton index was achieved and the results of treatment were satisfactory. CONCLUSIONS: Malocclusion with mandibular congenital missing teeth can be treated successfully guided by Bolton index.

Adolescent↗
PubMed2003

[Effect of elastic stress on expression of corebinding factor a 1 mRNA in human periodontal ligament cells in vitro].

OBJECTIVE: To investigate the osteoblast-like characteristics of human periodontal ligament cells affected by elastic stress in vitro, and the role of corebinding factor a 1 (cbfa1) in alveolar bone formation during orthodontic tooth movement. METHODS: Rat dig-labeled cbfa1 cDNA probe was prepared from SD rat osteoblasts cultured in vitro. Human periodontal ligament cells were cultured on the elastic bottom plate and stimulated by elastic stress using mechanical loading system for cultured cells in vitro. The expression of cbfa1 mRNA was detected by in situ hybridization method. RESULTS: Cbfa1 mRNA express in human periodontal ligament cells stimulated by elastic stress and did not express in normal human periodontal ligament cells. CONCLUSION: It is suggested that elastic stress plays a role in the differentiation process from human periodontal ligament cells to osteoblast-like cells. Cbfa1 is a transcription factor in alveolar bone remodeling during orthodontic tooth movement.

Adolescent↗
PubMed2002

[Development of an analysis system for X-ray cephalometry by Windows platform].

Here in this paper introduced is an analysis system for X-ray cephalometry developed through Windows platform,which includes three parts: data input, cephalometry analysis & calculation, and display & printing of diagnostic results. It has been applied in orthodontic department of Stomatological Hospital of the Fourth Military Medical University, and it is quite convenient for doctors' cephalometry diagnosis.

Cephalometry↗