Frontiers in Surgery (Jul 2017)

The Use of Cone Beam Computed Tomography in Assessing the Insertion of Bone Conduction Hearing Implants

  • Tim George Ate Calon,
  • Martin Lars Johansson,
  • Martin Lars Johansson,
  • Elske Larissa van den Burg,
  • Anna Maria Louisa Janssen,
  • Marc van Hoof,
  • Robert Jan Stokroos

DOI
https://doi.org/10.3389/fsurg.2017.00038
Journal volume & issue
Vol. 4

Abstract

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ObjectiveThis study aimed to compare postoperative cone beam CT (CBCT) imaging to implant stability quotient (ISQ) measurement and direct caliper measurements as a suitable technique to assess bone conduction hearing implant (BCHI) seating and insertion depth.MethodsIn vitro, BCHIs were completely (n = 9) and partially inserted (n = 9) in bone blocks of different densities and subsequently scanned. Scans were processed using 3DSlicer 4.3.1 and Mathematica 10.3. ISQ measurements were obtained for all BCHIs mounted with different abutment lengths (9, 12, and 14 mm). CBCT imaging was performed for patients with a clinical indication.ResultsIn vitro, 95% prediction intervals for partially inserted and completely inserted BCHIs were determined. ISQ values significantly decreased with partial insertion, low-density artificial bone, and longer abutment lengths. Evaluation of in vitro and in vivo 3D models allowed for assessment of insertion depth and inclination.ConclusionCBCT imaging allows to study implant seating and insertion depth after BCHI surgery. This can be useful when visual confirmation is limited. It is possible to distinguish a partial BCHI insertion from a complete insertion in artificial bone blocks. This technique could prove to be a valuable research tool. In vitro, ISQ values for Ponto BCHIs relate to abutment length, insertion depth, and artificial bone density.

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