Occlusal force transfer by removable partial denture designs for a radical maxillectomy.

Area of Science:

• Dental prosthetics
• Biomaterials engineering
• Biomechanics

Background:

• Surgical resection of the maxilla presents challenges for removable partial denture (RPD) rehabilitation.
• Understanding stress distribution from RPD retainers is crucial for long-term success and patient comfort.
• Photoelastic analysis offers a method to visualize stress patterns in dental models.

Purpose of the Study:

• To evaluate and compare the stress distribution of various removable partial denture retainer designs.
• To assess the impact of physiologic adjustment on stress reduction in RPD frameworks.
• To identify optimal retainer designs for stress management in post-maxillary resection patients.

Main Methods:

• Testing multiple RPD retainer designs on a photoelastic cast of a surgically resected human maxilla.
• Utilizing photoelastic stress analysis to visualize and quantify stress concentrations under load.
• Comparing stress patterns between physiologically adjusted and unadjusted RPD frameworks.

Main Results:

• Physiologic adjustment dramatically reduced stresses when frameworks were in place.
• Adjusted frameworks produced less damaging stress in supporting structures compared to unadjusted ones.
• High stresses were consistently observed in the premolar region across all designs.
• Lingual retainers generated higher stress concentrations than buccal retainers.
• The I-bar retainer with a cingulum rest proved most effective for anterior force transmission.

Conclusions:

• Physiologic adjustment is critical for minimizing stress in RPD frameworks.
• Infrabulge I-bar retainers (buccal or lingual) offer the most equitable stress transfer.
• Light wire circumferential and cast circumferential swing-lock retainers show less favorable stress distribution.