Wide Diameter Bone-anchored Hearing System Implants: a Comparison of Long-term Follow-up Data Between Tissue Reduction and Tissue Preservation Techniques

Objective: To present long-term data on the Wide Ponto implant bone-anchored hearing system (BAHS) in regards to implant stability, soft tissue reaction and implant loss for two case series undergone either the tissue reduction- or the tissue preservation surgical technique.

Methods: Comparison of two consecutive, prospective case series. Each case series enrolled 24 patients. The case series underwent one-stage implantation of the Wide Ponto implant BAHS using either a linear incision technique with subcutaneous reduction or a linear incision technique without subcutaneous reduction. Implant stability quotient (ISQ) values were measured using resonance frequency analysis and soft tissue reactions were graded according to Holgers' classification system. Follow-up visits were performed at 10 days, 6 weeks, 6 months, 12 months and annually up to 4 years (tissue preservation) or 5 years (tissue reduction) postoperatively.

Results: The two case series had homogenous patient populations and followed an identical postoperative scheme. The ISQ values increased consistently the first 12 months for both groups (p ≤ 0.001), and were higher in the tissue preservation case series, (p = 0.04, 9 mm abutment). More than 91% of the soft tissue observations were assessed as Holgers' grade 0 or 1. One implant (2.1%) was lost due to trauma.

Conclusion: In both case series, the Wide Ponto implant showed increasing implant stability during the follow-up period from the time of surgery, irrespective of surgical technique, indicating good osseointegration. Soft tissue reactions were rare and of minor severity. Implant survival was high.