Mandibular growth following distraction osteogenesis in children with craniofacial microsomia from a skeletal units perspective.

Background: Mandibular growth following distraction osteogenesis (DO) in patients with craniofacial microsomia (CFM) remains unclear. We aimed to investigate both the short- and long-term effects of DO on mandibular growth in children with Pruzansky-Kaban type IIA CFM based on skeletal units.

Materials and methods: We collected computed tomography data from 15 children with CFM preoperatively(T0), immediately after distractor removal(T1), and 4-6 years after distractor removal(T2). Measurements were taken to assess the size and orientation of the skeletal units. Linear and angular measurements were analyzed to evaluate the short- and long-term effects of DO. Bilateral differences in growth rates (GRs) for each unit between T1 and T2 were assessed.

Results: Preoperatively, the affected side exhibited smaller condylar and body units than the unaffected side. From T0 to T1, there was a significant increase in the body unit and normalization of the skeletal unit orientation on the affected side. However, from T1 to T2, the GRs of the units on the affected side were significantly slower than those on the unaffected side. Although the condylar and body unit length on the affected side did not show statistically significant increases, the angular unit length decreased. Relapses were also observed in the alignment of the units on the affected side.

Conclusions: Our findings suggest a potential long-term inhibitory effect of early DO on mandibular growth in children with CFM. This issue requires further attention as strategies to promote the growth of skeletal units following DO are critical for optimal long-term treatment outcomes.