Alveolar split osteotomy for the treatment of the severe narrow ridge maxillary atrophy: a modified technique.

Alveolar bone splitting and immediate implant placement have been proposed for patients with severe atrophy of the maxilla in the horizontal dimension. A new modification of the classical alveolar bone splitting for the treatment of the narrow ridge in the maxilla is provided. Thirty-three dental implants in eight consecutive patients were evaluated retrospectively following the described modified split-crest osteotomy. Inclusion criteria were: inadequate maxillary buccolingual dimension, 3-4mm of crestal width, and sufficient height from alveolar ridge tip to maxillary sinus floor. Primary stability was calculated using resonance frequency analysis (RFA). Alveolar bone height was measured in the panorex pre- and postoperatively. Histological bone examination was assessed following trephine bone harvesting during the second operation. Mean follow-up was 28.33 months. Bone regeneration of the inter-cortical gap occurred in 98% of implant sites (implant survival rate 100%). Mean implant stability quotient (ISQ) for the whole series of implants was 69.48. At the second operation, mean loss of the alveolar bone height was 0.542mm. Predictable results are obtained using the modified split-crest osteotomy. This technique provides an acceptable inter-cortical gap, decreases the risk of necrosis of the outer cortex, and provides a firm-wall box for the placement of particulate bone grafting.