Mandible reconstruction plate: patient-specific and 3D printed

Segmental defects of the mandible can best be bridged with a patient-specific reconstruction plate, possibly in combination with an autologous bone graft (fibula, iliac crest,…). Such a plate is designed to preserve the apprearance of the original mandible, fits perfectly and guarantees an accurate execution of the pre-planned mandible resection and reconstruction.

 
Standard reconstruction plates are fully straight and need to be cut and bent before or during surgery with special (heavy and expensive) tools. This is time-consuming and difficult and never leads to a perfect fit on the anatomy. To counter the poor fit, the use of locking screws is a necessity. Pre-bending also introduces stresses in the plate, leading to earlier failure.
Patient-specific plate: Pre-planned and complete freedom of design

The shape of our patient-specific reconstruction plate is designed prior to the surgery, based on the CT-scan of the patient. It is designed to follow the surface of the mandible before resection or to follow the surface of any bone graft (fibula, iliac crest,…). Screw fixation is planned based on the local bone thickness and quality. To achieve a more mechanically stable three-point fixation and to save height, Y-shaped or triangular plate endings are possible. (In standard plates you sometimes destroy the joint capsule of the TMJ in an attempt to use enough screws).

Unlike standard plates, bridging sections can be designed without regular screw holes that weaken the structure.

An increase of the interface area between bone and plate and a triangular screw configuration diminishes the mechanical stress further, which may consequently allow a reduction of plate thickness.

Since the reconstruction plate perfectly fits the patient’s mandible, there is no need for locking screws.

3D printed titanium

The final design of the reconstruction plate is 3D printed in Ti6AL4V (grade 5), which is a much stronger alloy than the titanium alloy used for the pliable standard plates. Stronger titanium also has a higher fatigue limit and since the plate does not require bending, no bending stresses are introduced, leading to a longer expected lifetime of the custom 3D printed plate.

  Ultimate Tensile Strength
Standard plate (titanium grade 2) 345 MPa
3D printed custom plate (titanium grade 5) 1100 MPa

Why use 3D printing? Plates that are milled have to be designed very smooth and therefore they can’t follow small irregularities in the bone surface, leading to a less than optimal fit. 3D printing allows us to produce plates  that match the tiny irregularities and therefore offer a perfect fit. And we waste less material while making them!

 
Save time and money

Preoperative planning combined with a patient-specific mandible reconstruction plate can reduce operation time with 1 to 1,5 hour at a OR rate of 48 – 103 dollars per minute. Furthermore you save 30-60 minutes of plate bending.

Osteosynthesis plates

The above also applies to our patient-specific osteosynthesis plates; we can provide custom plates, based on the surgical planning so you don’t need to bend plates on a model and you can be assured that fixating bone fragments with these plates results in bone positioning as planned.

Comparison: Xilloc reconstruction plates vs other 'customized' reconstruction plates

At Xilloc we are specialists in real patient-specific products. Unlike big medical device manufacturers, all our business processes are tuned towards making a perfect product for a surgeon to help one individual patient; from our online ordering system MedX, to our biomedical engineers and our design and manufacturing methods.

Xilloc patient-specific mandible reconstruction plate “Customized” reconstruction plate from big medical device company
  • perfect fit on the mandible (and bone graft)
  • customized fit; the plate follows the general contour, but does not conform exactly to the anatomy of the bone
  • 3D printed in the anatomical shape
  • often milled straight and then bent
  • Very strong Ti6Al4V (Titanium grade 5)
  • Softer titanium grade 2 to allow bending
  • Y-shape and triangular plate endings for increased stability
  • only linear plates  possible


 

Full Mandibular implants

In 2011 Xilloc had a world première with the design and production of the very first customized 3D-printed lower jaw (in titanium). The implant procedure was carried out on an 83-year old patient with a serious jaw infection. This procedure rescued important vital functions (breathing, speech, chewing, sensation) as well as the aesthetic aspect that would otherwise have been lost. 

 

Partial Mandibular implants

Segmental defects of the mandible are often bridged with a large titanium reconstruction plate in combination with e.g a fibula graft. When no bone graft is available, a partial mandible reconstruction can be designed and produced in titanium.