title: The bone regenerative effect of growth hormone on consolidation in mandibular distraction osteogenesis of a dog model.
abstract: The purpose of this project was to study the effect of growth hormone on early bony consolidation in distraction osteogenesis of a dog model. Sixteen dogs were used for this study. The vertical osteotomy on the mandibular body was extended downward. An external distraction device was applied to the mandibular body and the mandibular distraction was started 5 days after the operation at a rate of 1 mm/d up to a 10-mm distraction. The experimental group was divided into a control group and growth hormone group. Dogs in the growth hormone group received a daily subcutaneous injection of 100 microg (1 IU) of recombinant human growth hormone per kilogram of body weight. The daily administration of growth hormone was performed from the day of the osteotomy through the whole distraction period to the sacrifice. Normal saline was injected in the control group. Eight dogs were allocated to each group. Two dogs in each group, a total of four dogs, were killed at 2 weeks after completion of distraction, four dogs were killed at 4 weeks, and the other eight dogs were killed at 6 weeks. The level of serum IGF-I in the growth hormone group was elevated and peaked between 8 days and 12 days after systemic administration of growth hormone. Bone mineral density was higher in the growth hormone group and lower in the control group for the whole period. Bone mechanical strength was 300% higher in the growth hormone group than in the control group. However, results were more suggestive than conclusive. On histological examination, the formation of a substantial amount of active woven bone was observed throughout the distracted zone at six weeks in the growth hormone group. In the control group, new bone was generated from the edge to the center of the distracted zone. In addition, most of the central area of the distracted zone was filled with fibrous tissue at six weeks. In conclusion, these findings suggest that growth hormone appears to be effective in early bony consolidation in distraction osteogenesis.
authors.affiliation: Department of Plastic and Reconstructive Surgery, School of Medicine, Kyungpook National University, Samduk 2-ga 50, Taegu-city 700-721, Korea. bccho@knu.ac.kr
authors.forename: Byung Chae
authors.initials: BC
authors.lastname: Cho
authors.forename: Jeong Hwan
authors.initials: JH
authors.lastname: Moon
authors.forename: Ho Yun
authors.initials: HY
authors.lastname: Chung
authors.forename: Jae Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Ick Chan
authors.initials: IC
authors.lastname: Kweon
authors.forename: In San
authors.initials: IS
authors.lastname: Kim
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects; D001861:Bone Regeneration / Q000187:drug effects*; D004285:Dogs; D019382:Human Growth Hormone / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000187:drug effects / Q000378:metabolism; D008334:Mandible / Q000033:anatomy & histology / Q000187:drug effects* / Q000601:surgery; D023421:Models, Animal; D019647:Oral Surgical Procedures / Q000379:methods; D010012:Osteogenesis / Q000187:drug effects*; D019857:Osteogenesis, Distraction / Q000379:methods*; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology
chemical_list: D011994:Recombinant Proteins; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I