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Updated: Jul 18, 2026

Creating Rigidly Stabilized Fractures for Assessing Intramembranous Ossification, Distraction Osteogenesis, or Healing of Critical Sized Defects
Published on: April 11, 2012
Monobloc advancement by distraction osteogenesis decreases morbidity and relapse
James P Bradley1, Joubin S Gabbay, Peter J Taub
1Los Angeles, Calif.; and New York, N.Y. From the Division of Plastic and Reconstructive Surgery, University of California, Los Angeles, and Division of Craniofacial and Pediatric Plastic Surgery, Westchester Medical Center.
Background:
Treatment of midface hypoplasia and forehead retrusion with monobloc advancement is associated with significant complications, including meningitis, prolonged intubation, and frontal bone flap necrosis. To see whether distraction of the monobloc segment offered decreased morbidity, the authors compared clinical outcomes of patients who underwent conventional monobloc advancement with those of patients who underwent monobloc distraction.
Methods:
Group 1 (conventional monobloc; n = 12) underwent traditional monobloc advancement with bone grafting. Group 2 (modified monobloc; n = 11) did not receive ventriculoperitoneal shunts and underwent the above procedures with placement of a pericranial flap and fibrin glue over the midline defect. Group 3 (monobloc distraction; n = 24) underwent advancement of the monobloc segment by distraction osteogenesis using internal distraction devices. Complications included meningitis, cerebrospinal fluid leak, frontal bone flap loss, and wound infection. Preoperative, postoperative, and follow-up lateral cephalograms were used to assess horizontal changes of the forehead, midface, and maxilla.
Results:
Group 3 (distraction monobloc) had the lowest complication rate (8 percent), followed by groups 2 (modified monobloc; 43 percent) and 1 (conventional monobloc; 61 percent) (p < 0.05). Group 3 achieved greater advancement (12.6 mm) than did group 2 (9.4 mm) or group 1 (9.1 mm) (p < 0.05). Relapse was least in group 3 (8 percent) compared with groups 2 (67 percent) and 1 (45 percent).
Conclusions:
Monobloc advancement by distraction osteogenesis had less morbidity and achieved greater advancement with less relapse compared with conventional methods of acute monobloc advancement with bone grafting. Monobloc distraction is superior to conventional methods of acute monobloc advancement and is an alternative to staged fronto-orbital advancement followed by Le Fort III advancement.

