The Concept of Distraction Osteogenesis Established by Illizarov

The Concept of Distraction Osteogenesis Established by Illizarov in the field of orthopedic surgery. 1

Advantages of Distraction Osteogenesis • • • No need for a donor site No limit to lengthening Simultaneous lengthening of the surrounding soft tissues, such as skin, muscle, blood vessel, and nerves 2

Distraction Osteogenesis Gradual, controlled displacement of a surgical fracture resulting in simultaneous formation of new bone and expansion of adjacent soft tissue. 3

Distraction Osteogenesis Procedures • Surgery : osteotomy gap of 4 mm • Latency period : for 5 -7 days • Activation period : 1 mm, once each day for several days Martin Chin (1999) 4

Distraction Osteogenesis Procedures • Fixation period : left in place for 10 days or few weeks without activation • Consideration period : lead screw removal and left to considerate for 6 ~ 10 weeks. Martin Chin (1999) 5

Osseointegration in Distracted Segments • Entered 10 to 16 weeks after completion of the activation phase. • The implants remain submerged for 5 months. Martin Chin (1999) 6

Surgical Technique • Horizontal incision in vestibule & subperiosteal dissection. • Vertical osteotomy (not involving ridge crest) : extending through both the labial and lingual cotex. Martin Chin (1999) 7

Surgical Technique • Horizontal osteotomy : should not compromise the continuity of the mandible or encroach on the inferior alveolar nerve • Drilling a hole for lead screw through the crestal mucosa without flap reflection. Martin Chin (1999) 8

Surgical Technique • Transport segment is mobilized by wedging an osteotome into horizontal osteotomy. • Crestal component of the osteotomy requires greenstick fracture at the crest to achieve mobility. Martin Chin (1999) 9

Surgical Technique • Insertion of distraction devices : threaded rod, two small bony plates fabricated from titanium. Martin Chin (1999) 10

Devices for Distraction Osteogenesis • Intraosseous distracting device (Alveolar distractor, ACE Surgical Supply) • OMS 5000 oscillating microsaw (Nouvag) • Osteotomes Urbani et al. (1999, IJPRD) 11

Surgical Technique • Crestal incision • Full thickness mucoperiosteal flap (buccal only) • Lingual flap was left in place : constant blood supply through the periosteum. • Osteoplasty for ideal ridge form : minimum width of 5 mm Urbani et al. (1999, IJPRD) 12

Surgical Technique • Horizontal 1. 0 to 1. 5 mm wide osteotomy on the buccal aspect 7 -8. 5 mm inferior to the crest. • Saw penetrating to the border of the lingual plate. • Vertical osteotomy to receive distraction implant. • Distractor base plugs were inserted. Urbani et al. (1999, IJPRD) 13

Surgical Technique • 5 mm-long alveolar distraction implant was inserted. • 2 vertical osteotomies were made mesially and distally to release the bony segment. • Bone chisel was used to fracture through the lingual plate and free the bony segment • Stage 2 axial screw was inserted. Urbani et al. (1999, IJPRD) 14

Surgical Technique • On the 5 th day the distraction screw was rotated 2 full turns. : one full turn = 0. 5 mm vertical distraction • The screw, on average, were changed every 2 days. • A period of 10 days was needed to reach the proper vertical augmentation. Urbani et al. (1999, IJPRD) 15

Surgical Technique • Covered with final healing screw. • Allowed to heal for an additional 30 days before the alveolar distraction device was removed. • Implants are place in the site where the distraction device had been removed. Urbani et al. (1999, IJPRD) 16

Relapse of Distraction • Bone resorption of the transport segment • Distraction loss by sinking the implants into the cancellous bone of the base segment under masticatory pressure • Distraction loss by tension from surrounding soft tissue. Oda et al. (2000, JOMI) 17