Deproteinized Bovine Bone in Alveolar Bone Critical Size Defect (>2cm) Secondary to Cyst Removal
Condition: Maxillary Cyst
MeSH terms: Cysts
Study type: Interventional
Phase: Phase 2

Summary: 
      The aim of this study was to evaluate the effect of the use of deproteinized bovine bone as a
      filler material of critical-sized (diameter >=20 mm) bony defects derived from the excision
      of maxillary and mandibular cysts. 20 patients were considered.

      Patients were randomly divided into 2 groups according to the type of treatment: the bone
      defect was filled with granules of deproteinized bovine bone (test); no filling material
      (control). Clinical parameters were recorded at 7 days, 1, 6 and 12 months after surgery.
      Radiological follow up consisted of an orthopantomograph and a CT scan taken at the baseline
      (pre-operatory) and 12 months after surgery.

      In order to evaluate the difference in percentage of filling of the bone defect between the
      two groups, the pre-op and the 1-year radiolucent volumes were evaluated in the CT scans.
    

Detailed description: 
      The healing of extensive alveolar bone defects secondary to cyst removal is not predictable.
      Residual voids of various entity may persist. Some Authors proposed the use of grafting
      materials to reconstitute the loss of hard tissue. The primary objective was to determine the
      efficacy of bone grafting.The secondary objectives were to evaluate the incidence rate of
      wound dehiscence, pus drainage, recurrence and other complications 7 and 30 days and 6 months
      after surgery. Recurrence at 12 months of healing was also evaluated. For all patients
      included, surgeries were performed in conscious sedation and local anesthesia.Full-thickness
      flap of the appropriate shape and dimensions were lifted, and the bone exposed. When
      necessary, osteotomy was done, in order to enucleate the cystic lesion. The residual bone
      cavity was filled with deproteinized bovine bone (test), or not filled with any graft
      material (control). The flap was finally repositioned and sutured in order to achieve primary
      closure.

      In both test and control groups antibiotic therapy with amoxicillin tablets of 1 g every 12
      hours for six days (alternatively, for allergic patients, clarithromycin 500 mg tablets twice
      daily were given) and proper analgesics were prescribed. Postoperatory physical, therapy was
      prescribed as well.

      Radiological follow up consisted of an orthopantomography and a CT scan taken at 12 months
      after surgery.For bone volume evaluation, a computerized method was adopted to compare the
      pre-operatory and the 12 months post-operatory CT scan. The Digital Imaging and Communication
      in Medicine (DICOM) obtained files were transferred to a Mac Pro Quad 2.66- GHz work- station
      (Apple Corp., Cupertino, CA, USA) and analyzed using an open-source medical image processing
      software (OsiriX v. 5.8.5, Pixmeo Sarl, Bernex, Switzerland). The margin of the radiolucent
      areas of each CT slice was traced manually on each axial view, and the volume calculated by
      the software with the ROI (Region Of Interest) tool. Volumes in mm3 and 3D images were
      obtained for each pre-op and post-op ct scan, for every test and control patient. Each exam
      was evaluated by two assessors (GL and SR) who were trained in radiological diagnosis and
      measurement detection. The volumetric reduction of the cysts was calculated by subtracting
      the preoperatory from the post operatory volumes, both in test and control groups.
    

Intervention name(s): Deproteinized bovine bone; granules of deproteinized bovine bone (Bio-Oss)
Intervention type(s): Biological; Device
Intervention description(s): cyst removal followed by heterologous bone grafting
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Bio Oss; critical-size defect; bone grafting; cyst; CT bone analysis; alveolar bone