Computed tomographic analysis of outer XXXX for osseointegrated bone-anchored hearing system insertion.

@entity30037 @entity1 @entity9332 @entity2319 @entity702 @entity393
INTRODUCTION: Osseointegrated bone-anchored hearing systems (BAHSs) are a useful tool in auditory rehabilitation for single-sided @entity2319 and conductive/mixed @entity393 . They rely on adequate osseointegration of @entity702 implants, which can be limited by @entity9332 . This study examines adult computed tomographic (CT) temporal bone normative data for @entity9332 in the areas commonly recommended for BAHS insertion and identifies hazards that may compromise the osseointegration process. METHODS: Prospective analysis of 100 consecutive adult helical CT scans. Calvarial thickness was measured in axial and coronal planes 5.5 cm posterior to the superior external auditory canal at 6 vertical points ( @entity30037 cm). Other parameters measured include temporal bone pneumatization and the presence of suture lines, bone marrow, and vascular structures. RESULTS: A total of 195 temporal bones were examined in 100 @entity1 . Mean @entity1 age was 60.9 years, of whom 54.4% were @entity1 and 45.6% were @entity1 . Mean @entity9332 was greatest at +1 cm above the @entity30037 level (6.3 mm) and thinnest at +4 cm (5.1 mm). Of temporal bones, 55% had at least 1 site thinner than 4 mm and 21% had at least 1 site thinner than 3 mm. Air cells and suture lines were more likely to be encountered within 2 cm above the @entity30037 level, and marrow space is more likely to be encountered 3 to 4 cm above the @entity30037 level. DISCUSSION: Selecting a position 3 to 4 cm above the level of the @entity30037 is more likely to result in dural exposure for a 3-mm BAHS abutment, especially in @entity1 . Selecting a position near the level of the @entity30037 provides thicker bone, but the surgeon is more likely to encounter suture line or enter mastoid air cells. Preoperative CT imaging may be a useful tool in evaluating @entity9332 and hazards when planning BAHS insertion in the adult population.
