title: The effect of chitosan bead encapsulating calcium sulfate as an injectable bone substitute on consolidation in the mandibular distraction osteogenesis of a dog model.
abstract: OBJECTIVE
  The purpose of this project was to study the effect of chitosan bead encapsulating calcium sulfate, which provides a sustained release of chitosan and calcium sulfate after implantation, on early bony consolidation in distraction osteogenesis of a dog model.
  
  
  METHODS
  Forty-five dogs were used for this study. An external distraction device was applied to the mandibular body after a vertical osteotomy and mandibular distraction was initiated 5 days after the operation at a rate of 1 mm/day up to a 10-mm distraction. The experimental group was divided into a control group (I), hyaluronic acid group (II), chitosan group (III), calcium sulfate group (IV), and chitosan bead encapsulating calcium sulfate group (V). Normal saline was injected in group I. In group II, 1 mL of hyaluronic acid solution was injected into the distracted region. In group III, 1 mL of injectable solution of chitosan mixed with hyaluronic acid was implanted. In group IV, 1 mL of injectable solution of calcium sulfate mixed with hyaluronic acid was implanted. In group V, an injectable form of powdered chitosan bead encapsulating calcium sulfate mixed with 1 mL volume of hyaluronic acid was implanted.
  
  
  RESULTS
  Bone mineral density was 12% of the contralateral normal mandible at 3 weeks, 23.4% at 6 weeks in group I, 15% at 3 weeks, 29.1% at 6 weeks in group II, 16% at 3 weeks and 32% at 6 weeks in group III, 30.4% at 3 weeks and 52.8% at 6 weeks in group IV, and 33.6% at 3 weeks and 55% at 6 weeks in group V with statistical significance (P < .005). The mean 3-point failure load was compared with the intact contralateral mandible and noted to be 12% in the control group, 16% in group II, 18% in group III, 34.3% in group IV, and 31.7% in group V. Difference of mean percentages between one group and another was statistically significant (P < .005). In the histologic findings, new bone was generated in all groups. In groups IV and V, the formation of active woven bone was observed throughout the distracted region at 6 weeks. The amount of new bone formation in the distracted zone was in the order of group IV and V, III and II, and the control group.
  
  
  CONCLUSIONS
  These findings suggest that chitosan bead encapsulating calcium sulfate appears to facilitate early bony consolidation in distraction osteogenesis.
authors.affiliation: Department of Plastic and Reconstructive Surgery, College of Medicine, Kyungpook National University, Daegu, Korea. bccho@knu.ac.kr
authors.forename: Byung Chae
authors.initials: BC
authors.lastname: Cho
authors.forename: Ho Yun
authors.initials: HY
authors.lastname: Chung
authors.forename: Dong Gul
authors.initials: DG
authors.lastname: Lee
authors.forename: Jung Duk
authors.initials: JD
authors.lastname: Yang
authors.forename: Jae Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Kyung Ho
authors.initials: KH
authors.lastname: Roh
authors.forename: Go Un
authors.initials: GU
authors.lastname: Kim
authors.forename: Dong Sin
authors.initials: DS
authors.lastname: Lee
authors.forename: Ick Chan
authors.initials: IC
authors.lastname: Kwon
authors.forename: Eun Hee
authors.initials: EH
authors.lastname: Bae
authors.forename: Kwang Ho
authors.initials: KH
authors.lastname: Jang
authors.forename: Rang Woon
authors.initials: RW
authors.lastname: Park
authors.forename: In San
authors.initials: IS
authors.lastname: Kim
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015519:Bone Density; D001861:Bone Regeneration; D018786:Bone Substitutes / Q000008:administration & dosage*; D002133:Calcium Sulfate / Q000008:administration & dosage; D048271:Chitosan / Q000008:administration & dosage; D003799:Dental Stress Analysis; D004285:Dogs; D006820:Hyaluronic Acid / Q000008:administration & dosage; D008334:Mandible / Q000601:surgery*; D019186:Mandibular Advancement / Q000379:methods*; D008863:Microspheres; D023421:Models, Animal; D019857:Osteogenesis, Distraction; D018583:Pliability
chemical_list: D018786:Bone Substitutes; D006820:Hyaluronic Acid; D048271:Chitosan; D002133:Calcium Sulfate