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

## TL;DR

This study compares bone formation outcomes in patients with cleft lip and palate who received early or late bone grafting, finding similar success rates but differences in bone bridge types.

## Contribution

The study provides new insights into the effectiveness of early versus late secondary alveolar bone grafting in cleft patients.

## Key findings

- Early-SBG group had significantly smaller cleft width compared to late-SBG group.
- Early-SBG group showed a significantly higher ratio of type A bone bridges compared to late-SBG group.
- Late-SBG patients achieved adequate bone bridge formation and cleft gap closure similar to early-SBG patients.

## Abstract

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.

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.

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).

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.