Comparison of Bone Formation After Early and Late Secondary Alveolar Bone Grafting in Patients With Unilateral and Bilateral Cleft Lip and Palate

Abstract

Objectives

Late-stage secondary alveolar bone grafting (SBG) has a poor prognosis; however, the case selection and timing of orthodontic treatment have not been thoroughly investigated. This study aimed to clarify the prognosis of early-SBG and late-SBG in patients with unilateral or bilateral cleft lip and palate.

Materials and Methods

Fifty-six patients underwent early-SBG performed before the eruption of the cleft-adjacent lateral incisors or canines (early-SBG group). Ten patients underwent late-SBG requiring significant tooth movement for gap closure; SBG was performed before phase II treatment for treatment efficiency, and tooth movement began approximately 3 months post-SBG (late-SBG group). Pre-SBG cleft width was measured; bone-bridge formation using the Chelsea scale and cleft gap closure post-SBG were evaluated. Types A and C bone bridges were considered adequate. These items were statistically compared between groups.

Results

Cleft width in the early-SBG group was significantly smaller than that in the late-SBG group (p < 0.001). There were no significant differences in the percentage of adequate bone-bridge formation (p = 0.055) and cleft-gap closure (p = 1.000) between groups. However, the ratio of type A bone bridges was significantly higher in the early-SBG group than in the late-SBG group (p = 0.035).

Conclusion

These results suggest that, even in late-SBG, early orthodontic tooth movement to the graft bone leads to the formation of an adequate bone bridge, similar to early-SBG. However, the maintenance of cervical grafted bone after late-SBG may be less than that after early-SBG.