Ultrasonographic Evaluation of Bone Formation after Maxillary Distraction Osteogenesis in Patients with Unilateral Cleft Lip and Palate

Abstract

Objective: Ultrasonographic (US) observation was carried out in order to investigate bone formation and remodeling after distraction osteogenesis (DOG) using the rigid external distraction (RED) system.
Patients and method: The patients were seven cases of unilateral cleft lip and palate treated using the RED system: six males and one female with the mean age of 19 years. The amount of maxillary advancement by DOG ranged from 7.5 to 17.5mm and the timing of US observation was from 2.2 to 6.9 years post-DOG. B mode US examination of the distracted maxillary anterior wall was performed with a 14-MHz transducer. Bone formation and remodeling were assessed on both cleft and non-cleft sides by evaluating bone continuity and smoothness of the distracted bony gap, respectively.
Results: Continuity of the cortical bone was recognized in six cases, but was, not detectable in one case. On the other hand, the distraction gap was not recognizable in one case on both sides; was obvious in four cases on both sides; and was obvious on the cleft side and detectable on the non-cleft side in two cases.
Conclusion: The diverse aspects of bone formation and remodeling suggest that continuous monitoring is needed after maxillary DOG using the RED system.