Surgically assisted rapid palatal expansion: orthodontic preparation for clinical success.

Close root proximity between the maxillary central incisors presents a problem in the surgical management of a maxillary palatal expansion. During the surgical fracture of this interdental area, the possibility exists for a separation to occur between the root surface and the bone. If this does occur, it is paramount that the gingival attachment remain intact. Asymmetric separation places more stress on the mesial gingival attachment because of the anatomy of the gingival fiber apparatus. Gingival detachment results in epithelial downgrowth in an apical direction, which in turn prevents bone apposition in a coronal direction. The resulting osseous defect is difficult to treat with an osseous graft procedure, as there are few if any intrabony walls. Treatment planning should include analysis of a recent periapical radiograph of the incisor roots to determine the need for orthodontic root separation before surgery. A postsurgical periapical radiograph should be taken to determine where the interdental separation has occurred. The expansion schedule should be adjusted depending on the symmetry of the separation and the health of the gingival attachment.