What are the considerations for combining total joint replacement with double jaw surgery to correct bite alignment?

Combined Total Joint Replacement and Double Jaw Surgery for Bite Correction

Custom total joint prostheses combined with double jaw surgery is a viable and effective approach for patients requiring both TMJ reconstruction and bite correction, with studies showing significant improvements in pain, function, and quality of life. 1

Benefits of Combined Approach

• Improved surgical efficiency: Combining TMJ replacement with orthognathic surgery allows for simultaneous correction of both joint dysfunction and malocclusion in a single procedure 2, 1
• Enhanced long-term outcomes: Custom total joint prostheses have demonstrated sustained improvement in:
  • Pain-free mouth opening
  • Correction of facial asymmetry
  • Reduced recurrence of TMJ problems
  • Improved quality of life 3
• Functional improvements: Studies show significant post-operative enhancements in:
  • Maximum interincisal opening
  • Jaw function during chewing
  • Reduction in TMJ pain 1, 4

Considerations for Combined Surgery

Patient Selection

• Best suited for skeletally mature patients with end-stage TMJ disorders 2
• Ideal candidates have:
  • Failed conservative management (soft diet, anti-inflammatories, physical therapy)
  • Functional impairment (limited mouth opening, difficulty eating)
  • Severe pain affecting daily activities 1

Prosthesis Selection

• Custom vs. Stock Prostheses: Custom-designed TMJ replacement devices demonstrate better surgical efficiency and long-term quality of life improvements compared to stock devices 1
• Material Considerations:
  • UHMWPE (Ultra-high molecular weight polyethylene) remains the gold standard for bearing surfaces
  • Ti6AL4V alloy is preferred for major components due to biocompatibility 2
  • Consider pre-implantation screening for metal allergies via skin patch tests or lymphocyte transformation tests 2

Surgical Planning

• 3D CT scans and models are essential for proper planning 2
• Virtual surgical planning allows for:
  • Precise positioning of the prosthetic components
  • Optimal screw placement to avoid mandibular nerve damage 5
  • Accurate prediction of post-operative occlusion 6

Potential Complications and Management

Immediate Complications

• Facial nerve weakness: Usually transient 1
• Prosthesis dislocation: Most common within first six weeks post-operatively 2
  • Prevention: Maintain muscular stability and proper adaptation of prosthetic components

Long-term Complications

• Prosthetic joint infection:
  • Most common organisms: Staphylococcus aureus (53%) and Propionibacterium acnes (33%)
  • Prevention: Prophylactic antibiotics (1st or 2nd-generation cephalosporins) one hour prior to surgery 1
• Condylar component screw loosening:
  • Risk factors: Excessive anterior rotation of condylar component 7
  • Prevention: Proper component orientation and adequate screw configuration 7
• Metal hypersensitivity reactions: Occurs in 10-15% of patients 1

Expected Outcomes

• Success rate: Combined TMJ and orthognathic surgery has shown an overall success rate of 91.4% based on improved mouth opening (>35mm) and decreased pain 6
• Functional limitations: Expect some reduction in anterior movement of the prosthetic condyle and restricted protrusion/lateral excursions compared to natural joints 4
• Long-term stability: Orthognathic procedures combined with TMJ surgery have demonstrated good long-term stability 6

Post-operative Care

• 7-10 day course of oral antibiotic prophylaxis 1
• Consider antimicrobial photo-disinfection therapy combined with chlorhexidine gluconate body wipes to reduce bacterial burden 1
• Regular follow-up to monitor:
  • Maximum interincisal opening
  • Pain levels
  • Occlusal stability
  • Prosthesis integrity

The combined approach of total joint replacement with double jaw surgery represents an advanced solution for patients with both TMJ dysfunction and malocclusion, offering comprehensive correction with predictable and stable results when performed by an experienced surgical team.