الفهرس 
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Abstract
Summary
Distraction osteogenesis (DO) is a biologic process that promotes bone
formation between cut osseous surfaces that are gradually separated by
incremental traction. (The technique of bone lengthening by DO was first
described in 1905 by codvila, (but it remained undeveloped until Dr GavrielA.
Ilizarov, a Russian physician, further developed the technique in the 1950s in
Kurgan in West Siberia.
DO developed and used in craniofacial region with successful experience
and promising results with many draw backs The main drawbacks is the
inferior bone quality of bone regenerate especially with rapid distraction
compared to normal bone, and several studies were conducted either clinically
or experimentally to improve bone quality and quantity
The present study was conducted to evaluate the effect of stem cells
application in rapid distraction rate on the quality and quantity of mandibular
new bone regenerate following DO in goats. The rapid distraction rate was 2
mm/day.
The study was conducted on 14 goat. The animals were divided to two
equal groups. Group I (Study group), the distraction rate was 2 mm/day for
five days with application of stem cells at the end of distraction twice one after
10 days and second application after 20 days (3 million cell). Group II
(Control group), the distraction rate was 1 mm/day for 10 days.
Animal were examined clinically through the study. Samples were
dissected from the animal cadavers to be assessed radiographically by cone
beam computed tomography to assess distracted bone dimension and density
and histological assessment of bone samples stained by Trichrome Masson
stain and H&E stain. Results were tabulated and assessed by independent
sample t-test to assess statistical significance, Cohen’s d to assess sample size
and concordance correlation coefficient to measure to assess the interexaminer
error of assessment.
Radiographic evaluation showed decrease in distracted bone dimension
but of no statistical significance which may be attributed to small sample size.
Radiographically there was an increase in bone density with no statistical
significance but the CBCT method of assessment needs improvement in
further studies because unfortunately there was poor correlation between the
examiners. Histological and histomorphic evaluation showed highly
significant improvement in bone trabeculae size and bone quality. Stem cells
showed promising results in improving bone quality of the distraction
osteogenesis bone regenerate and compensated the bad effect of rapid
distraction on bone, but still in need for further examination