Mandibular Distraction Devices

Advantages of Distraction:

• no need for bone grafts
  - lower infection risk
  - no atrophy of implanted bone
  - no donor side morbidity
  - less trauma to the patients

• surrounding soft tissue is expanded simultaneously with distraction of defective bone

• distracted bone is malleable prior to the consolidation phase and results can be corrected immediately after bone distraction which reduces the likelihood of relapse

• relatively simple operative technique

Indications:

Primary:

• Severe open mandibular fractures

• Highly comminuted closed fractures

• Nonunions and delayed unions, especially those associated with infection

• Fractures associated with infection

Secondary:

• Tumour resections

• Facial deformity corrections

• Burn maintenance

• Bone-grafting defects

Available Distractors:

Bi-Directional Distractor
 
Most hypoplasia of the lower jaw affects the ascending ramus, elongation at this site can result only through the optimal positioning of the Uni-Directional distractor, i.e., vertically or obliquely as indicated. When the congenital mandibular deficiency is such that both the ramus and body of the mandible are affected, a multidirectional distraction is required.

The Bi-Directional distractor allows, a variable adjustment in the angle between the two arms of the appliance. Following a single or double osteotomy, one can distract both vertically and horizontally. In very difficult cases of mandibular hypoplasia, a double osteotomy can be done to obtain two callus sites. This creates a mandibular angle.

Multi-Directional Distractor

Mandibular micrognathia, is either congenital or arises from early childhood temporomandibular joint trauma.

Because the midface adapts to the mandible in the early growth phases, a disturbance in mandibular development results in decreased midface development as well. Current methods of treatment are either orthodontic for a period before the patient can have orthognathic surgery at the appropriate age or costochondrial grafts which will also require orthognathic surgery at a later stage.  Alternately, the Multi-Directional Distractor may be used at an earlier age, avoiding secondary growth disturbances in the maxilla.

The Multi-Directional Distractor provides the benefit of allowing transverse movements as arms can be changed in all planes independent of one another.

The selection of the appropriate distractor depends upon the individual deformity, as well as the condition at the point of placement.

The degree of hypoplasia and the age of the patient determine the number (1 or 2) and location of the osteotomies, as well as the approach to the operative area.