AtlasSurgeryDistraction Osteogenesis

Maxillofacial Surgery

Distraction Osteogenesis

aka DO · Callotasis

Gradual mechanical lengthening of bone through an osteotomy that stimulates new bone formation in the distraction gap — powerful for severe hypoplasia.

Rate
1 mm/day
Latency
5–7 d
Consolidation
≥2× activation

§ 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)

Question 1

Standard activation rate:

Question 2

Consolidation phase relative to activation:

Question 3

Principle originally described by:

References

  1. McCarthy JG. Plast Reconstr Surg 1992

Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.