Objective: To assess the feasibility of internal transport disk distraction osteogenesis (ITDDO) for the regeneration of segmental mandibular defects and to evaluate the effect of radiation therapy.
Design: Prospective case series.
Setting: Tertiary care academic medical centre.
Methods: Nine patients were accrued (M:F 6:3; mean age 63 years, range 37-77 years) and underwent ITDDO for the regeneration of segmental mandibular defects. The mean follow-up time was 43 months (range 6-87 months). The average bony defect was 6.1 cm (range 3.0-10.0 cm).
Main outcome measures: Construct formation (graded as complete, partial, and none based on evidence of calcification on panorex films and palpation), complications, and plate exposure (grouped by those that were thought to be related to distraction and those that were independent of distraction).
Results: Construct formation was "complete" in two of nine patients (22%), "partial" in four of nine (44%), "none" in two of nine (22%), and one of nine patients (11%) died prior to the 6 month assessment point. Four patients did not undergo radiation therapy, and two had stable constructs 6 years after treatment completion. Five patients underwent radiation therapy, and none of these patients formed stable, ossified constructs. All patients experienced a complication, and seven of nine (78%) developed hardware exposure, with six contributing to construct loss.
Conclusions: Construct formation with ITDDO is possible for large composite mandibular defects in patients who have not received radiation. The complication rate was unacceptably high but may improve with better patient selection, refinement in surgical technique and distractor design, and tissue engineering for construct support.