Mandibular Distraction - Dynamic Osteosynthesis System

Indications

Mandibular lengthening

• using local anesthesia in patients that refrain from general anesthesia;
• of larger magnitude;
• in syndromatic patients with integumental deficiency;
• in obstructic sleep apnea syndrome;
• after malunited subcondylar fractures;
• after standard orthognathic surgery complicated by condylar resorption.

Prerequisites

Moderate linguoversion of the lower anterior teeth or labioversion of the upper anterior teeth is allowed (not reverse). Other dental compensations in the anterior region should be treated orthodontically before the surgery. There should be no premature contacts upon protrusion.

The third molars are removed during surgery if they are impacted. Heavy Kobayashi hooks are installed, or otherwise surgical archbars applied.

Tubes with hook without offset and lingual cleats on the bands of the upper and lower first molars are preferred. Occasionaly the bands form the second molars have to be removed.

Radiology

Lateral cephalometric analysis provides information on the length of the posterior fixation unit, and the length of the spacer. The length of the spacer is chosen according to the thickness of the mucosa in the retromolar area, the position of the osteotomy line (in line with the vertical joint of the distractor), and the depth the screw may enter the bone. An orthopantomogram (Panorex view) is necessary to judge the thickness of the lower border and its relation to the mandibular canal.