Adding a low-resorption rate graft and a membrane will reduce the bone loss.

 in my experience it is imperative to add a bone graft preferable a xenograft

1- between the splitted cortical plates to mintain the space that you gain

2- on the buccal aspect inorder to have a proper cover and avoid bone loss

3- it is advisabe to cover 1-2mm the top of the ridge , this area has the highest rate of resorption