Distraction Osteogenesis

§ overviewOverview

Biological process of new bone formation between vascularised bone segments gradually separated by traction (Ilizarov principle applied to craniofacial skeleton).

§ classificationClassification

• 01By vector: unidirectional, bidirectional, multidirectional
• 02By device: extraoral, intraoral tooth-borne, intraoral bone-borne
• 03By site: mandibular, maxillary, alveolar, midface (RED, Le Fort III)

§ planTreatment Planning

• 01Latency phase 5–7 days
• 02Activation 0.5–1 mm/day (usually 1 mm split into 2 turns)
• 03Consolidation ≥ 2× activation period (8–12 weeks)
• 04Vector planning with 3D CT and stereolithographic models

§ surgicalSurgical Management

• 01Corticotomy preserving medullary blood supply and periosteum
• 02Placement of distractor with correct vector
• 03Rigid fixation; activation begins after latency

§ complicationsComplications

• 01Device failure, screw loosening
• 02Vector deviation, malocclusion
• 03Nerve injury (IAN)
• 04Infection at pin site
• 05Premature consolidation
• 06TMJ ankylosis

§ prognosisPrognosis

Excellent for large advancements (>10 mm) with lower relapse than conventional osteotomy; especially useful in growing patients and syndromic hypoplasia.

§ examKey Examination Points

• 01Confirm vector before activation
• 02Monitor occlusion during activation
• 03Assess IAN function

§ revisionQuick Revision Summary

• 01Latency 5–7 d · rate 1 mm/d · consolidation 2× · Ilizarov principle

§ vivaBDS Viva Questions

• 01What are the phases of DO?
• 02Advantages over conventional osteotomy?
• 03Indications in the maxillofacial region?

§ mcqsMCQs — Assessment (3)

§ relatedRelated Diseases