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

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

JOURNAL=Frontiers in Surgery

VOLUME=4

YEAR=2017

URL=https://www.frontiersin.org/journals/surgery/articles/10.3389/fsurg.2017.00038

DOI=10.3389/fsurg.2017.00038

ISSN=2296-875X

ABSTRACT=<sec id="ST1"><title>Objective</title><p>This 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.</p></sec><sec id="ST2"><title>Methods</title><p><italic>In vitro</italic>, BCHIs were completely (<italic>n</italic> = 9) and partially inserted (<italic>n</italic> = 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.</p></sec><sec id="ST3"><title>Results</title><p><italic>In vitro</italic>, 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 <italic>in vitro</italic> and <italic>in vivo</italic> 3D models allowed for assessment of insertion depth and inclination.</p></sec><sec id="ST4"><title>Conclusion</title><p>CBCT 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. <italic>In vitro</italic>, ISQ values for Ponto BCHIs relate to abutment length, insertion depth, and artificial bone density.</p></sec>