title: Use of bioglass for orbital volume augmentation in enophthalmos: a rabbit model (oryctolagus cuniculus).
abstract: OBJECTIVE
  To investigate the clinical and histologic response of Novabone-C/M as an osteoproductive alloplastic implant for volume augmentation in the orbit in the treatment of enophthalmos and to compare its outcome alone versus its use in combination with autogenous bone or Medpor granules.
  
  
  METHODS
  Novabone-C/M, a bioactive silicone glass material, was implanted in the subperiosteal space of the left orbit of 12 New Zealand White rabbits. The animals were divided into 3 groups, each with 4 animals, based on the material implanted in the orbit: group 1, Novabone alone; group 2, Novabone plus Medpor granules; and group 3, Novabone plus autogenous bone fragments. All rabbits were studied clinically, radiographically, and histologically at 1-, 3-, and 6-month intervals. Animals underwent preoperative and postoperative computed tomography (CT) with 3-dimensional reconstruction, proptosis measurements, and volumetric analysis. Orbit specimens were studied histologically with mineralized bone stain (MIBS) to look for bone formation, reactivity, infection, implant resorption, and migration.
  
  
  RESULTS
  There were no signs of significant inflammation or infection. Subcutaneous migration of the implant was seen radiographically but not clinically in groups 1 and 3. Induced proptosis averaged 2.5 mm (at 1 month) and showed regression in all groups over a 6-month period but was not statistically significant. Implant volume was markedly reduced in all groups, averaging 69% in group 1, 37% in group 2, and 59% in group 3 at 6 months. New bone formation and bone remodeling was present in all 3 groups at 3 months and only in group 2 at 6 months. The rate and amount of implant remodeling and bone formation was greatest in the Novabone/Medpor group (group 2).
  
  
  CONCLUSIONS
  Bioglass particulate is biocompatible, easy to use in the orbit, and stimulates bone growth. Bioglass is associated with volume loss and migration over 6 months and may not provide adequate volume augmentation in the orbit when used alone for the treatment of enophthalmos. The duration and amount of bone formation may be enhanced when Novabone is used in conjunction with Medpor.
authors: Texas Oculoplastic Consultants, Austin, Texas, USA. malena_amato@hotmail.com
authors: Malena M
authors: MM
authors: Amato
authors: Sean M
authors: SM
authors: Blaydon
authors: Frank W
authors: FW
authors: Scribbick
authors: Cliff J
authors: CJ
authors: Belden
authors: John W
authors: JW
authors: Shore
authors: Russell W
authors: RW
authors: Neuhaus
authors: Patrick S
authors: PS
authors: Kelley
authors: David E E
authors: DE
authors: Holck
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology; D016723:Bone Remodeling; D018786:Bone Substitutes / Q000494:pharmacology; D016025:Bone Transplantation; D002516:Ceramics / Q000494:pharmacology; D015841:Enophthalmos / Q000601:surgery*; D005094:Exophthalmos / Q000000981:diagnostic imaging; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D009915:Orbit / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D010012:Osteogenesis / Q000187:drug effects; D011095:Polyethylenes; D019736:Prostheses and Implants; D011817:Rabbits; D012828:Silicones / Q000494:pharmacology; D014057:Tomography, X-Ray Computed
chemical_list: D001672:Biocompatible Materials; C022107:Bioglass; D018786:Bone Substitutes; C084562:Medpor; C481262:Novabone-C-M; D011095:Polyethylenes; D012828:Silicones