209 A Comparison of Soft Tissue Reactions Seen with Different Bone Anchored Hearing Aid Abutments: Smooth-Titanium Vs Hydroxyapatite-Coated

Aim Bone Anchored Hearing Aids allow hearing via stimulation of the cochlear through bone conduction. These devices are largely successful; however, soft tissue reactions often hinder their benefit. The type of abutment used could contribute to complications. We aimed to investigate whether using smooth-titanium abutments instead of hydroxyapatite-coated abutments reduced the rate of soft tissue reactions and need for revision surgery. Method A retrospective cohort analysis of all patients who received a Bone Anchored Hearing Aid during a 3-year period. An electronic database was screened for skin reactions and surgical revisions. A comparison was made between patients who received a hydroxyapatite-coated abutment and smooth-titanium abutments. The same surgical technique, linear incision skin preservation surgery, was used for inserting both abutments. Results Sixty-six patients received a Bone Anchored Hearing Aid. Forty-five patients received hydroxyapatite-coated abutments and twenty-one received smooth-titanium abutments, two patients had smooth-titanium inserted bilaterally. The groups were significantly similar with regards to age and gender. Significantly more patients who received hydroxyapatite-coated abutments recorded soft tissue reactions, 77.78% vs 23.81% (p < 0.0001). Significantly more patients who received hydroxyapatite-coated abutments required surgical revision, 40% vs 9.52% (p = 0.0197). 17.14% underwent skin revision and change of abutment. 5.7% had the abutments removed and were not immediately replaced. Conclusions When utilising skin preservation surgery for Bone Anchored Hearing Aid insertion smooth-titanium abutments have a favourable complication profile; with less soft tissue reactions and subsequent need for revision surgery, in comparison with hydroxyapatite-coated abutments. The reasons behind these differences warrant further investigations.

Case of oculo-auriculo-vertebral spectrum: rare clinical features

A 2-month-old boy presented to us with bilateral microtia, left lower motor neuron facial palsy, micrognathia, hemivertebra, bifid rib, bifid thumb and absent/hypoplastic right-sided depressor anguli oris. He had bilateral external auditory canal atresia, although response to loud sound was present. Brain stem evoked response audiometry (BERA) was advised at 3 months of age. Karyotype was normal. We diagnosed him as a case of oculo-auriculo-vertebral spectrum. Child was discharged on request by the family with the plan for bone-anchored hearing aid after BERA and plan for pinna and ear canal reconstruction at a later age but child did not come for any follow-up visit. On telephonic enquiry, it was found that he is thriving well but has developmental delay including speech delay. We conclude that children presenting with external ear abnormalities should be screened for multiple congenital anomalies so that a multidisciplinary approach to management can be planned.

Salivary Gland Choristoma of the Middle Ear in a Child: A Case Report

Salivary gland choristoma is an extremely rare middle ear pathology. We present the case of a 10-year-old girl with unilateral conductive hearing loss. Tympanotomy showed a nonspecific middle ear mass, absence of stapes, anomaly of incus, and displaced facial nerve. It was not possible to remove the mass completely. Histology confirmed salivary gland choristoma. The hearing in this case can be improved with a bone-anchored hearing aid.

Bioinstructive Micro-Nanotextured Zirconia Ceramic Interfaces for Guiding and Stimulating an Osteogenic Response In Vitro

Osseous implantology’s material requirements include a lack of potential for inducing allergic disorders and providing both functional and esthetic features for the patient’s benefit. Despite being bioinert, Zirconia ceramics have become a candidate of interest to be used as an alternative to titanium dental and cochlear bone-anchored hearing aid (BAHA) implants, implying the need for endowing the surface with biologically instructive properties by changing basic parameters such as surface texture. Within this context, we propose anisotropic and isotropic patterns (linear microgroove arrays, and superimposed crossline microgroove arrays, respectively) textured in zirconia substrates, as bioinstructive interfaces to guide the cytoskeletal organization of human mesenchymal stem cells (hMSCs). The designed textured micro-nano interfaces with either steep ridges and microgratings or curved edges, and nanoroughened walls obtained by direct femtosecond laser texturing are used to evaluate the hMSC response parameters and osteogenic differentiation to each topography. Our results show parallel micro line anisotropic surfaces are able to guide cell growth only for the steep surfaces, while the curved ones reduce the initial response and show the lowest osteogenic response. An improved osteogenic phenotype of hMSCs is obtained when grown onto isotropic grid/pillar-like patterns, showing an improved cell coverage and Ca/P ratio, with direct implications for BAHA prosthetic development, or other future applications in regenerating bone defects.

Application of Acceptable Noise Level to Confirm Fitting Strategy for Bone-Anchored Hearing Aid

Since there is no standardized fitting procedure for bone-anchored hearing aid (BAHA) patients, many clinics have failed to perform their successful fitting. The present case study tried to identify whether acceptable noise level (ANL) was clinically applied as one of fitting procedures for the BAHA users. Four hearing-impaired adults with BAHA (3 female and 1 male) who had a period of hearing deprivation for at least 8 years and the BAHA experience of more than 1 year participated. They conducted ANL in their unaided and aided BAHA conditions after being familiar with the ANL instruction. Also, the subjects responded to a self-report of Korean version of Profile of Hearing Aid Benefit (K-PHAB) to subjectively check amount of satisfaction with BAHA. Compared to the unaided condition, two out of four BAHA users showed a decreased ANL in the aided condition whereas the other users had a slightly increased ANL. Regardless, their levels were examined within the permissible range except for one subject. Their K-PHAB scores were similar to the ANL results in the aided condition. Although measured ANLs were slightly differed from the users, the current results suggest that ANL might be a tool to measure individual’s inherent value when the BAHA fitting being appropriated while also supported by K-PHAB scores. In the following study, we need to confirm a typical pattern of many BAHA users with longitudinal measures of ANL.