Craniofacial titanium implants and chronic pain: histologic findings

Area of Science:

• Biomaterials science
• Oral and maxillofacial surgery
• Histopathology

Background:

• Percutaneous titanium implants are used for craniofacial prostheses and bone-anchored hearing aids.
• Chronic pain at the implant site can occur despite conservative treatment.
• Understanding the histologic factors associated with implant pain is crucial for improving patient outcomes.

Purpose of the Study:

• To investigate the histologic features and histomorphometric outcomes of retrieved craniofacial titanium implants.
• To determine if any histologic findings correlate with chronic pain at the implant site in the temporal bone.

Main Methods:

• Histologic examination and histomorphometric measurements were performed on seven retrieved titanium implants and surrounding bone tissue.
• Implants were retrieved from four patients experiencing chronic pain at the implant site.
• Qualitative light microscopy and quantitative measurements of bone-to-metal contact and bone area were conducted.

Main Results:

• Soft tissue zones were observed at the implant interface, particularly under the flange.
• Inflammatory cells were present in the interface of all seven implants.
• Implants with poor bone-to-metal contact showed more extensive soft tissue and skin reactions.

Conclusions:

• The exact cause of chronic pain associated with these craniofacial titanium implants remains unclear.
• Common histologic findings included inflammatory cells and soft tissue zones at the interface.
• A variable degree of bone-to-metal contact was observed among the retrieved implants.