A jaw ridge can be tall enough to hold an implant and still too narrow for one. The ridge split technique cuts along the top of the ridge, separates its outer and inner bone walls, and opens a gap between them for new bone to fill.1
A systematic review of 35 studies found an average width gain of 3.06 mm (95% CI 3.01 to 3.12), and implants placed into split ridges survived at 98.17% across 4,446 cases.1
What the technique gains
The 3.06 mm figure held up in a sensitivity check. The reviewers dropped one study rated at high risk of bias and reran the pooled estimate, and the average width gained moved only slightly, to 2.99 mm.1 A gap of roughly three millimeters is often the difference between a ridge that cannot take a standard-diameter implant and one that can.
A graft inside the split: no significant difference in width
Surgeons often pack graft material into the space the split opens up, on the assumption that it helps hold the gap or adds bone volume. In the pooled data, ridges grafted at the time of the split gained 2.97 mm, against 3.06 mm in ridges left to fill on their own, and the review found no statistically significant difference between the two.1 That is not proof a graft adds nothing to the split; it means this review found no significant difference in width between grafted and ungrafted ridges.
Placing at the same time or later
An implant can go into a split ridge during the same operation as the split, or the surgeon can let the widened bone mature first and place it later. Both timings produced high survival in the pooled data, though the two rates are not identical.1
| Implants | Survival | |
|---|---|---|
| Simultaneous placement | 4,103 | 97.72% |
| Delayed placement | 343 | 99.14% |
| Overall | 4,446 | 98.17% |
Delayed placement came out a little ahead, but that figure rests on only 343 implants against 4,103 for simultaneous placement, roughly a twelfth as many.1 Without that context, a reader could conclude that waiting is the better choice, and this review does not support that conclusion.
Questions patients ask
Does adding a bone graft during a ridge split make it wider?
This review did not find a statistically significant difference in width gained between grafted and ungrafted ridges: 2.97 mm with a graft against 3.06 mm without.1
Is it better to place the implant during the split or wait?
Both timings did well in the pooled data. Simultaneous placement survived at 97.72% across 4,103 implants, and delayed placement at 99.14% across 343.1 The delayed figure looks higher, but it rests on roughly a twelfth as many implants, and the choice of timing depends on more than survival alone.
How much wider does a ridge split actually make the bone?
An average of 3.06 mm, with a 95% confidence interval of 3.01 to 3.12. Excluding one study rated at high risk of bias moved the pooled figure to 2.99 mm.1
References
- Al Haydar B, Kang P, Momen-Heravi F. Efficacy of Horizontal Alveolar Ridge Expansion Through the Alveolar Ridge Split Procedure: A Systematic Review and Meta-Analysis. Int J Oral Maxillofac Implants. 2023;38(6):1083–1096. doi:10.11607/jomi.9972
This page describes published clinical practice. It is not a treatment plan, and it does not replace an examination.