Extraoral Disk Implants' Stability in Irradiated and Nonirradiated Bone

Area of Science:

• Oral and Maxillofacial Surgery
• Biomaterials Science
• Oncology

Background:

• Extraoral (EO) implants, particularly disk implants, are crucial for maxillofacial prosthesis retention.
• Patients undergoing resective surgery for cancer often receive radiation therapy, which can compromise bone quality for subsequent implant procedures.
• Irradiated bone presents challenges due to reduced quality and increased infection risk, potentially impacting implant stability.

Purpose of the Study:

• To prospectively evaluate and compare the stability of disk implants in irradiated versus non-irradiated bone.
• To assess the influence of radiation therapy on the long-term osseointegration and stability of extraoral disk implants.
• To investigate site-specific differences in implant stability between irradiated and non-irradiated bone.

Main Methods:

• Prospective clinical study design.
• Inclusion of patients requiring extraoral disk implants, categorized by prior radiation therapy status.
• Assessment of disk implant stability over time using standardized measurements.
• Site-specific analysis (orbital vs. nasal) of implant stability.

Main Results:

• Disk implants demonstrated significantly higher stability in non-irradiated bone compared to irradiated bone across all implant types.
• Implant stability in non-irradiated bone showed consistent significant increases throughout the follow-up period.
• In irradiated bone, stability increased significantly only during the initial osseointegration phase (first two time points), with no further significant changes.
• Orbital disk implants showed significantly better stability in non-irradiated bone; this effect was also observed for double nasal disk implants.

Conclusions:

• Disk implant stability is significantly compromised in irradiated bone compared to non-irradiated bone.
• The osseointegration and long-term stability of disk implants are negatively affected by prior radiation therapy.
• Site-specific factors, particularly in the orbital region, further highlight the disparity in implant stability between irradiated and non-irradiated bone.