Effect of growth hormone and therapeutic ultrasound on mandible and mandibular condyle

• Author / Creator

  Khan, Imran

• Previous studies have shown growth hormone and therapeutic low intensity pulsed ultrasound can enhance mandibular growth separately. The aim of this study is to evaluate the concomitant effect of both of these applications on mandibular growth in rat. Methods: 24 male Sprague Dawley rats were divided into four groups, 6 in each. Groups 1, 2, 3, and 4 were designated as untreated control, recombinant rat growth hormone, Low Intensity Pulsed Ultrasound, and combination of both groups respectively. After 21 days of daily treatment on mandibular condylar, mandibles from euthanized rats are dissected, and scanned by MicroComputed Tomography to measure the mandibular bone volume, bone surface area, and condylar bone mineral density. Also Real-time Polymerase Chain Reaction was performed on the extracted livers’ C-fos, C-jun, and IGF-1 genes expressions. Results: Groups 2, 3 and 4 showed significant (p<0.05) growth stimulation when compared to the untreated control group. However, there was no statistical significant difference between groups 2, 3 and 4 with regard to bone volume or surface area. Conversely, condylar bone mineral density for group 4 was significantly reduced than groups 1, 2, and 3. Rats’ weights were not significantly different among the treatment groups after the treatment was performed. Additionally, gene expression study showed that the expression of C-jun, in harvested livers for Group 4 was less than that of Group 2 showing fewer side effects. Conclusion: When growth hormone was applied to rats’ mandible together with therapeutic ultrasound, preferential increase in bone volume, and surface area occurred with the expense of condylar bone mineral density and with less potential side effects.

• Subjects / Keywords

  • Mandibular growth
  • Low Intensity Pulsed Ultrasound
  • Growth Hormone
  • Micro-computed Tomography

• Graduation date

  2011-06

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R34W5Z

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.